[HN Gopher] Webb captures iconic Horsehead Nebula in unprecedent...
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Webb captures iconic Horsehead Nebula in unprecedented detail
Author : rbanffy
Score : 1017 points
Date : 2024-04-29 15:31 UTC (1 days ago)
(HTM) web link (www.esa.int)
(TXT) w3m dump (www.esa.int)
| forrestthewoods wrote:
| Here's a link to the actual image.
|
| https://www.flickr.com/photos/nasawebbtelescope/53686360156/...
| mk_stjames wrote:
| The youtube link to a 'zoom' in video to the image:
|
| https://www.youtube.com/watch?v=TkVprNB5XbI
|
| What is really, really neat to notice isn't just the detail in
| that final image.... look behind it, and there are whole edge-on
| spiral galaxies in the distance. Not stars. Galaxies.
|
| The nebula is about 1375 light years away. Those galaxies in the
| distance.... are billions of light years away. It's hard to
| comprehend.
| lionkor wrote:
| There really is a lot of stuff left to see for the first time
| patates wrote:
| "A lot" is the number of fish in a swarm maybe.
|
| This is so far away from our concept of counting things that
| the mind just gives up. There's no comparison, no dumbing
| down to X amount of football fields, just nothing.
|
| I find it depressing, confusing but also inspiring and
| fascinating at the same time.
| steve_adams_86 wrote:
| Yes, there is so much we can't possibly know or experience
| in our lifetimes, perhaps in the span of time our species
| will exist, to the extent that it becomes easy to imagine
| ourselves more like bacteria on a speck of dust floating in
| the air rather than on any scale towards the inverse. We're
| incredibly small in size and mental capacity.
|
| In ways the bacteria on the dust are oblivious to the scale
| and nature of the world around them, we seem similarly lost
| and hopeless in the pursuit of comprehending the universe.
| We just weren't built to grasp this kind of scale. We can
| enjoy images of the tiniest little slices of it, though.
| I'm actually very grateful for that. I think it'll be a
| source of endless wonder for my entire life.
| mr_mitm wrote:
| I heard comparisons of the number of stars in the
| observable universe to the number of all grains of sand on
| Earth's beaches, or the number of molecules in a bottle of
| air. Not sure if that helps anyone, though.
| patates wrote:
| The radius of the observable universe is estimated to be
| about 46.5 billion light-years. The Horsehead Nebula that
| they zoom into in the video is 0.000001375 billion light-
| years from Earth. I'm doing mind acrobatics to try to
| understand the scale but... nope! :)
| jll29 wrote:
| That feeling of awe, if that could be shared with most
| people on earth - perhaps they wouldn't waste their pity
| lives fighting each other.
| alex_suzuki wrote:
| Wasn't their recently an article on how witnessing a
| solar eclipse has a measurable effect on people's view of
| the world? It certainly affected me.
| rpozarickij wrote:
| I have never seen a solar eclipse in person, but I wonder
| whether this type of feeling has similarities with the
| overview effect [1].
|
| [1] https://en.wikipedia.org/wiki/Overview_effect
| dylan604 wrote:
| > look behind it, and there are whole edge-on spiral galaxies
| in the distance. Not stars. Galaxies.
|
| just to add to the awe of that, pretty much every "dot" in one
| of these images is going to be another galaxy. individual stars
| from within the Milky Way will have diffraction spikes and very
| obvious as a single item.
| TheVespasian wrote:
| It's dizzying even on the galactic scale to internalize that
| discrete, visible stars are "right there" compared to the
| general murkiness of the Milky Way. A sphere of very near
| stars _right_ next to us relatively speaking
| shagie wrote:
| There's also a zoom on the image on ESA -
| https://esawebb.org/images/weic2411a/
|
| The zoomable version:
| https://esawebb.org/images/weic2411a/zoomable/
| wrsh07 wrote:
| I found this mesmerizing. Particularly fun is to scrub forward
| and backward through the video to clarify where exactly you're
| looking. (I found it worked better on the embedded video in the
| article than the yt one, not sure why)
| coda_ wrote:
| Do you (or does anyone) know about how zoomed in the video is
| at the start? Like is that the milky way and are there some
| things in that starting frame that I could identify with the
| naked eye?
|
| It seems like it is already quite zoomed in to start with, but
| I can't tell how much.
| mk_stjames wrote:
| At the start of the video you are looking at a good potion of
| the whole visible sky. If you look at the very center of the
| frame, there is Orion, and you can see the three close bright
| stars together that we zoom in towards are Orion's belt.
| kibwen wrote:
| The zoom-in video at the end is utterly unbelievable, don't miss
| it. What an engineering and scientific triumph.
| p1mrx wrote:
| And it's in glorious 432p resolution!
|
| Edit: Here is the 2160p version:
| https://www.youtube.com/watch?v=UdHnF9Go_DQ
| mckn1ght wrote:
| I wonder how fast an observer would need to be traveling for it
| to look like that!
| p1mrx wrote:
| 99.x% the speed of light, but the image would be blueshifted
| and highly distorted.
| coder543 wrote:
| Since the images in the article are from infrared cameras,
| blue-shifting the light might just land the view from those
| IR images into the visible spectrum for the observer! Just
| need to tune the speed correctly.
| arbuge wrote:
| Particularly if you notice all the galaxies above the top of
| the gas cloud in the final frame.
| qwertox wrote:
| It's so very unlikely that there aren't millions of other
| lifeforms out there.
|
| Sometimes I think that life could well have been just my soul and
| no one else, but here I am sharing this world with billions of
| other people, trillions of other lifeforms on this planet alone.
| So it is possible that more than one lifeform exists, that they
| share this universe and communicate in it. Why shouldn't this
| also be possible on millions of other earth-like planets out
| there?
| kibwen wrote:
| Of course there are other lifeforms out there, it's
| statistically implausible for it to be otherwise. What's also
| implausible is that, given the impossible vastness and
| hostility of interstellar space, that any will ever manage to
| contact us, specifically. Fortunately, we've got lots of crazy
| lifeforms here on Earth to keep us occupied, if we can take a
| moment to stop extincting them as fast as we possibly can.
| nyokodo wrote:
| > Of course there are other lifeforms out there, it's
| statistically implausible for it to be otherwise.
|
| I'll grant you that once we have found a single other planet
| with life. Until then we're doing statistics on a single data
| point and no, the number of planets and galaxies etc are not
| sufficient to statistically determine the prevalence of life
| because as yet none of them are confirmed to have life. This
| is wishful thinking and statistical truthiness.
| xandrius wrote:
| This is only true if we believe Earth is special, which we
| have no bases. So I'll stick to statistics for now, thank
| you very much.
| mr_mitm wrote:
| Statistics is a very precise science. Can you show your
| work or is it just a gut feeling?
| xandrius wrote:
| I know nothing compared to people who work in the field,
| so I don't have my own work, I trust theirs.
| mr_mitm wrote:
| Whose work exactly? I'm always eager to read about this
| fascinating question.
| the_af wrote:
| > _Statistics is a very precise science. Can you show
| your work or is it just a gut feeling?_
|
| In my case, my gut feeling, but is it so unlikely?
|
| As mentioned in "Cosmos: Possible Worlds", planets may go
| through a "habitable zone", which is the window in which
| they are just the right distance from just the right
| star, and they have the right elements in their surface
| or whatnot. And then just the right random events have to
| happen and there's the spark of life. And then a
| gazillion extinction events must be averted, at times
| when the Tree of Life (to use the metaphor from Cosmos)
| is at its most fragile, when all of life could be cut
| down before its prime.
|
| It sounds unlikely for any single planet, any single star
| system, any single galaxy, etc. But on the grand scale of
| the universe, it cannot be that _nowhere else but here on
| Earth_ did this happen.
|
| I don't know if this is statistics. It surely is gut
| feeling. But I think it's the right kind of gut
| feeling...
| nyokodo wrote:
| > it cannot be that nowhere else but here on Earth did
| this happen. > I don't know if this is statistics. It
| surely is gut feeling.
|
| It's possible that life emerging is so unlikely that it
| has never happened before anywhere even if it could
| happen again. We do not have the data to establish how
| likely and in fact we don't even have enough data to fill
| in all the gaps of how life on earth emerged in the first
| place. Our gut feelings are likely heavily influenced by
| science fiction or other priors and can't be trusted for
| knowledge but we are as a species very good at deluding
| ourselves into thinking we know things that we don't.
| the_af wrote:
| But that's it. Life doesn't _seem_ so unlikely, does it?
| There are things we still don 't understand about it, but
| we understand some, and it's not magic. It can happen,
| given the right conditions, much like mold may grow on a
| piece of bread under the right conditions.
|
| What's difficult to comprehend is the immense vastness of
| the universe. It seems _unlikely_ that nowhere else did
| the preconditions for life arise, and in fact, it seems
| likely that they must have arisen in multiple places.
| Immensely many places, in fact. Considered like that, it
| 's _more_ unlikely that life didn 't appear anywhere else
| but in this Pale Blue Dot.
|
| We look at our planet, and all that had to happen for
| those first lifeforms to come into existence, and it
| seems _so unlikely_... but not impossible. And we 're
| playing with _a lot of dice_ here! Very hard not to roll
| a few sixes with a bag of dice so large.
| nyokodo wrote:
| > There are things we still don't understand about it,
| but we understand some, and it's not magic.
|
| > What's difficult to comprehend is the immense vastness
| of the universe.
|
| We know a whole lot about ways life changes once it's
| there but we haven't observed life emerging from non-life
| and our hypotheses for how life emerged on earth has more
| holes than swiss cheese and it doesn't have to be magic
| in order to be exceedingly improbable. And magnitudes
| work in both ways, if it is sufficiently improbable for
| life to emerge, let's say 1 chance in 1E100 against then
| even if you had dice rolls in proportion to all the
| subatomic particles in the universe (~1E80) multiplied by
| the number of seconds since the big bang (~4E17) then it
| would still be about 3 orders of magnitude against the
| likelihood of life emerging even once. In this scenario
| if the probability was 4E97 then we'd expect for life to
| have emerged once. Until we have the data to infer what
| the probability actually is we can't determine which
| scenario is the case.
| the_af wrote:
| True, we cannot determine the scenario.
|
| > _but we haven 't observed life emerging from non-life_
|
| But our laboratory is very, very small, so that proves
| little.
|
| And we know life emerged at least once, and it doesn't
| seem particularly improbable. That's what I mean by "not
| magic"; not that we understand every little step, but we
| have _some_ idea.
|
| I don't think it's scifi to believe it's unlikely only
| Earth has sparked life. The one thing that is unlikely is
| that we will ever witness life anywhere else, but that's
| a different problem.
| jcranmer wrote:
| If you're sticking to statistics, the right answer is we
| don't know enough. The general rule of thumb I've seen is
| that you want to see n * p >= ~20 to be able to
| accurately assess the probability.
|
| For the difficulty of evolution of life, we have a total
| N of 1-5 of life-could-have-evolved, depending on how
| optimistic or pessimistic you want to be about life's
| chances (could life have evolved on Venus? Mars? Titan?
| Europa? any other moons I'm forgetting about).
|
| At this point, the statistics says more about your priors
| than they do about actual data, since there's not enough
| data to actually do any statistics on.
| terryf wrote:
| Why does that make the earth special?
|
| Is the single one in a million dimensional one-hot vector
| special? Why?
|
| If only intelligent life can have this conversation then
| it will always be "but why us?!?!" well, it was random.
| Just the other random values don't get to ask the
| question...
| the_af wrote:
| > _If only intelligent life can have this conversation
| then it will always be "but why us?!?!" well, it was
| random_
|
| "It was random" in my opinion explains little. If it was
| sentient, maybe the dice would say "why did I land
| showing my '6' face? Why me?" and the answer would be
| many other dice landed showing their '6' faces. Random,
| but given enough dice rolling you'll get another '6'.
|
| The universe is finite but it's mind-boggingly large. I
| think Earth is special because a- I was born there,
| enough said, and b- it has just the right conditions
| _and_ luck for life to exist. But I don 't think it's _so
| special_ that it 's the only planet in the whole mind-
| boggingly large universe to be this way. There must be
| other planets/dice rolling out there.
|
| Until we find another such planet we cannot know for
| certain, but in my opinion it seems unlikely that these
| conditions don't exist anywhere else but on Earth. Why?
| Well, because the universe is so large -- the dice pool
| is very, very large.
| travisjungroth wrote:
| I do think there's other life out there. But just considering
| the other side, the statistical model only applies if the
| existence of life is _actually_ stochastic.
|
| If a farmer plants a single tree in the middle of a square
| mile plot and rips up anything else that grows, any Fermi
| approximations done by the tree are going to be quite
| misleading.
| xandrius wrote:
| Who's this galactic farmer you're talking about?
| travisjungroth wrote:
| One or more beings with power and intelligence many
| orders of magnitude higher than our own. To call it god
| or gods gives a religious tone to it that totally derails
| the discussion and I'm specifically avoiding. This isn't
| about going to church on Sundays.
|
| There are a few answers to the "Where are they?"
| question. One is that the parameters to the Drake
| equation mean life is so rare we actually are alone (as
| another commenter linked to). Another group of answers is
| that there is life, but something about the relationship
| between us means we don't observe them. Maybe they're
| hiding from us. Maybe they're hiding from everyone.
|
| I think the range of possible answers that people think
| of for this scenario is generally much too narrow. The
| power imbalances can be wildly greater than "they're
| avoiding us". We experience power imbalances this large
| every day. What's the relationship between a Petri dish
| of bacteria and a person? Imagine a culture of penicillin
| reasoning how it came to be.
|
| Maybe this universe is a total construction. Maybe it's
| partially constructed, in the same way a farmer "makes" a
| farm from the Earth. If anything like that is the case,
| stochastic models are completely the wrong way to reason.
|
| It would be like if I wove a basket. There's now at least
| one basket made by Travis Jungroth. Surely there must be
| more? Out of the millions of baskets made across time,
| what's the probability that only _one_ was made by me?
| Even for a low probability of any individual basket, the
| numbers start getting decent there's another out there.
|
| But there's not. I just... decided to make only one.
| zolland wrote:
| I suppose there could be a distinction, but that is the
| idea of God, and that is the rational foundation for
| God's existence in Abrahamic religions. Funny to think
| that scientific development could invoke faith in some
| ways.
| travisjungroth wrote:
| I'm specifically _not_ invoking faith. This doesn't
| support Abrahamic religions more than any other. The line
| of reasoning here applies just as much to Hinduism,
| simulation theory, many creation stories, zoo theory,
| etc.
| zolland wrote:
| The idea that the universe was created by a higher being
| applies to every religion, but does not invoke faith? If
| you were to believe that theory at all it would require
| faith. How else could you believe it? No matter what you
| call it, there is a leap of faith.
| travisjungroth wrote:
| Just to make sure we're on the same page, here's the
| definition of faith from Merriam Webster that I think
| applies: a(1): belief and trust in and
| loyalty to God (2): belief in the traditional
| doctrines of a religion b(1): firm belief in
| something for which there is no proof (2):
| complete trust
|
| The first thing is you don't have to "believe" in the
| idea I outlined to use it. It's just a condition under
| which a probabilistic explanation doesn't account for the
| lack of observed intelligent life. And, it hasn't been
| disproven. So that's a way any probabilistic model is
| incomplete.
|
| Second, we could come to seriously believe in this theory
| through consensus direct interactions with these higher
| powers. That wouldn't require a leap of faith at all. If
| robots showed up and were like "we were sent by your
| creators, they say you're doing great" and gave us a
| second moon as a present, that would be very strong proof
| of more powerful beings.
| zolland wrote:
| Yes, if we had direct contact with the higher being that
| created our universe, or any proof of their existence,
| humans would no longer require faith regarding the
| existence of God...
|
| How would you use this theory if you didn't believe it
| held any truth? You certainly can't draw any corollaries
| from it. If it is actually a relevant condition worth
| considering, then you must believe it to be tenable to
| some degree.
|
| There's a condition where when I kick a ball, just before
| I touch it, the ball actually invisibly flies to the moon
| and back and then moves forward. It would be a condition
| under which Newton's laws fail... but I would have to
| actually believe in that condition to some degree to
| _use_ it. It is also similarly unfalsifiable. With
| current observations it is scientifically untenable, and
| believing in that condition would require faith.
|
| Any model can be proven incomplete if you conjure up
| unfalsifiable conditions that exist outside its domain
| and believe in them.
|
| > b(1): firm belief in something for which there is no
| proof
|
| For you to use the theory of creation in any meaningful
| way you must believe it is tenable. For you to believe it
| is tenable, without being faithful, there must be proof.
| Proof of this existence comes in many forms, where is
| _your_ proof? Morality? Reason? Those aren 't entirely
| scientific proofs...
|
| Just to be clear, I'm not trying to censure or disprove
| creationism and the metaphysical systems built upon it,
| they are very important and super interesting... but I
| don't think any of them are without a bit of faith, and
| they are certainly beyond science's capabilities. This is
| why I was saying it was interesting that science could
| invoke faith in some way.
| the_af wrote:
| I think it's not the same. Religions are usually not
| _mainly_ about more powerful beings creating other
| beings. There 's always a whole set of prescriptive
| rules, "this is how you're supposed to live your life"
| that doesn't apply here.
|
| This is not a nitpick, it's actually the _main_ thing
| about religion. Giving meaning and purpose to life. The
| hypothesis of some beings creating the rest of life in
| the universe doesn 't provide this.
| xandrius wrote:
| Ok, now I see what you are going for.
|
| It's a compelling idea but there is no evidence helping
| it.
|
| For me, it's easier to take what we see in our own "lawn"
| and expand it outwards to the cosmos as a whole. A frog
| evolved from a single-cell as well as an elephant did,
| and the geological landscapes we see are the result of
| physics, time and random fluctuations. I apply that to
| every other galaxy and that's it.
|
| Of course, one could think that single cell to be
| "planted" like a seed would be but no supporting evidence
| for now (or ever?).
| travisjungroth wrote:
| _No_ evidence helping it? Not a single thing that's ever
| happened supports the idea that our current reality was
| constructed?
|
| > For me, it's easier to take what we see in our own
| "lawn" and expand it outwards to the cosmos as a whole.
|
| The uncomfortable thing about reality is that it's often
| different from what is easier for us.
|
| _What_ you choose to expand out into the galaxy or even
| the entire universe is a critical choice. You could
| choose to extend the relationships between plants, or how
| power structures develop, or the explosion of complexity
| localized on Earth, or the human tendency to purposefully
| create environments for life.
|
| > the geological landscapes we see are the result of
| physics, time and random fluctuations
|
| Most of them. Not all of them. Bingham Canyon Mine is an
| open pit 4km wide and 1.2km deep. El Teniente mine is
| 3,000km of tunnels up to 2km deep. There's Mount Rushmore
| and the Hoover Dam. There are artificial islands and
| nuclear test sites.
|
| That's all just in the last 150 years. Draw the trend of
| human progress and where does it end up a billion years
| from now?
|
| That's even just assuming the conditions that created the
| universe mirror the conditions here on Earth, which is a
| tremendous assumption. It might be like having a letter
| dropped through your door slot for the first time and
| reasoning the postal service is entirely made of paper
| folded and stuffed into other paper. The actual reality
| of mail carriers with pensions, trucks with antilock
| breaks and sorting machines bigger than any animal that
| has ever existed would be unfathomable. Anyone suggesting
| it would be easily dismissed in favor of a simpler and
| less correct explanation.
| the_af wrote:
| > _No evidence helping it? Not a single thing that's ever
| happened supports the idea that our current reality was
| constructed?_
|
| I'm curious. What evidence do you see?
| travisjungroth wrote:
| Mostly things that exist without other concrete
| explanations. Consciousness in humans and animals. A lack
| of contact with other intelligent life. The constants of
| the universe being such that the universe can exist at
| all and not do something like collapse on itself.
|
| The common report of having met non-human entities,
| especially when on psychedelics.
|
| Our own tendency to creat artificial worlds (farms, zoos)
| and simulations.
|
| None of it _proves_ anything or necessarily moves towards
| a constructed reality versus a specific alternative.
| the_af wrote:
| I understand you're not saying this is a proof of
| anything.
|
| However, I have a hard time understanding the connection
| between those things you list and "... and therefore this
| may be evidence of a constructed universe."
|
| I just don't see it. For example, things "without
| concrete explanations" are more easily chalked to our
| lack of understanding. Or even better, to the idea that
| there's no "why" to the universe, it just is; we can
| sometimes understand the "how" to some degree, if at all.
|
| I think some emergent properties like consciousness and
| others are elegantly hypothesized about in Stephen Jay
| Gould's "The Panda's Thumb". Some things arise as
| secondary structures to other things which more readily
| relate to the environment. Like some hypothesize -- mind
| you, not interested in whether this specific hypothesis
| is right or wrong, just an example -- that walking
| upright/hip posture may have precipitated the evolution
| of mammalian brain cortex as a side effect!
|
| I don't want to pick on or challenge your every sentence,
| because I understand this is just opinion and we're all
| entitled to it. But I really don't see where's the
| evidence for a constructed universe.
| jcul wrote:
| Have you read the dark forest trilogy?
| travisjungroth wrote:
| I haven't.
| the_af wrote:
| Re: your "creator beings", I think we cannot say for
| sure, but where is the evidence? It's an extraordinary
| claim with almost nothing backing it.
|
| You make a point here:
|
| > _What's the relationship between a Petri dish of
| bacteria and a person? Imagine a culture of penicillin
| reasoning how it came to be._
|
| But the difference between ourselves and bacteria is that
| we can reason about things other than our immediate
| surroundings; and about magnitudes other than those we
| live in. If bacteria in a Petri dish developed
| intelligence, curiosity about the world, and some sort of
| scientific method, might they not discover there is a
| world outside their Petri dish? Maybe they would get many
| things wrong, but wouldn't they be able to indirectly
| determine at least _some_ things about the wider universe
| (the lab!), even if they never get to meet us? And wouldn
| 't they be able to develop some tools to finally observe
| the human beings in the lab, at least partially? And
| finally, wouldn't they be able to think "hey, these
| scientists are not the gods of the sacred Protozoan Book,
| they must be made of the same building blocks as we
| are!". We're talking intelligent bacteria who go to
| university and publish papers, mind you.
|
| I don't think there is _any_ evidence about the
| hypothesis that life is a single occurrence, like a
| basket woven by Travis Jungroth. It _could_ still be
| true, but I think it 's one of the least interesting
| starting points to think about the universe. It's
| somewhat like solipsism; maybe it's true, but it leads
| nowhere -- and we cannot tell, anyway.
| mr_mitm wrote:
| First of all: the question needs to be qualified by what we
| mean by "out there". The galaxy? The observable universe? The
| entire universe?
|
| The universe might be infinite, in which case: yes, there is
| life out there. We know the probably of life forming on any
| given planet must be greater than zero, or else we wouldn't
| be here. From this we can deduce the average volume which
| contains exactly one planet with life, which must be finite.
| Whether it makes sense to talk about what could be happening
| beyond the cosmological event horizon is another discussion.
|
| If we are talking about the observable universe or an even
| smaller volume: How can you say it's statistically
| implausible without knowing the probability of life forming
| on any given planet? It might be incredibly small, yet
| greater than zero. Your line of reasoning is incredibly
| common but I can't help but feel like it's mainly driven by
| wishful thinking.
| phantompeace wrote:
| Probably extrapolating from the fact that life here on
| Earth being found in harsh conditions, and those conditions
| being likely to be found all over the universe.
| floxy wrote:
| "Dissolving the Fermi Paradox"
|
| https://arxiv.org/abs/1806.02404
| dudeinjapan wrote:
| Strong evidence for a race of horse-headed aliens.
| IggleSniggle wrote:
| Each galaxy is a neuron and we are a spec of electricity within
| a spec of a neuron experiencing ourself, the universe, in
| realtime, together, forever
| Barrin92 wrote:
| >that they share this universe and communicate in it. Why
| shouldn't this also be possible on millions of other earth-like
| planets out there?
|
| one trivial but powerful observation that von Neumann made was
| that our galaxy say, is actually pretty small. It's about 100k
| light years big, which means that any civilization spreading at
| only a tiny fraction of the speed of light could expand through
| the entire milky way in only a million years. _We_ could very
| well spread through the entire galaxy in the near future if we
| manage to get to like, 1% of light speed in the next few
| hundred years.
|
| So our galaxy, which contains a few hundred billion stars
| almost certainly has no other _intelligent_ life in it for the
| simple reason that it 'd be everywhere. That doesn't mean
| there's no microbial life or maybe technological life billions
| of light years out there but the fact that we're so alone in
| our neighborhood is a pretty strong indicator in the direction
| that advanced life might be much more rare than some people
| assume.
| lm28469 wrote:
| > So our galaxy, which contains a few hundred billion stars
| almost certainly has no other intelligent life in it for the
| simple reason that it'd be everywhere.
|
| By that account another civilisation as advanced as us would
| say they're equally alone in the galaxy no ? yet here we are.
| And you forget time, they might have done that 2b years ago
| and there is nothing left for us to detect, or they might do
| it in 2b years and we might not be there to witness it. Also
| there might be barriers we're not aware of, for example
| advanced civilisations could go through things like
| extinction through pollution, over consumption of resources
| before reaching a tipping point to being multi planetary, &c.
|
| Plus we're far from the only galaxy, there might be galaxy
| wide civilisations out there, far far away. And more
| important, nothing guarantees the premise of multi-planetary
| civilisation has any validity outside of sci-fi
|
| It's like going in the woods twice a year, not seeing
| mushrooms and concluding mushrooms don't exist on earth
| because surely you'd have seen them by now! The bottom line
| is that we just have absolutely no clue
| gitaarik wrote:
| Or we are as ignorant about the aliens as ants are about us.
| the_af wrote:
| I don't think this is a good indication.
|
| Assuming that von Neumann was right, and assuming it's even
| technologically possible to achieve 1% of light speed, here's
| some alternative explanations of why we don't see aliens in
| the Milky Way:
|
| - Maybe we're ahead of the race here. It's _unlikely_ , but
| it has to be the truth for some intelligent lifeform. Why not
| us? I admit this is unlikely.
|
| - Maybe galaxy exploration is _technically_ feasible but
| _economically_ unfeasible. Aliens would have to solve the
| same problems than us.
|
| - Maybe galaxy exploration is technically _and_ economically
| feasible, but the overwhelming majority of lifeforms go
| extinct before reaching this point, an none have been able so
| far (additional assumption: life is relatively new in the
| universe, much like it 's relatively new on Earth itself).
|
| - Maybe galaxy exploration is possible and evidence of life
| forms has reached us, but we didn't understand them because
| we weren't looking for the right things.
|
| - Maybe galaxy exploration is possible and aliens want us to
| remain untouched and unaware, much like some wish would
| happen with lost Amazonian tribes (only the aliens would be
| more successful).
| layer8 wrote:
| We don't know how large the universe is, and how (un)likely
| life is. Life _could_ very well be highly unlikely with respect
| to the size of the universe. We currently have no good way to
| tell. The only thing we know is that life is not impossible.
| brcmthrowaway wrote:
| r/Reincarnation
| SamLeBarbare wrote:
| Universe is fractal, Please stop iterating, it will cause a
| buffer overflow
| dudeinjapan wrote:
| I want them to zoom in further to find a horsehead with the
| horsehead. Mind blown!
| mjrpes wrote:
| We are but a breakpoint in an endless and eternal buffer
| overflow. Happy debugging!
| itishappy wrote:
| Wow. The NIRCam image is probably going to be the most exciting
| new photo, but I can't get over how well MIRI reveals the
| internal structure of the nebula.
|
| NIRCam:
| https://www.esa.int/ESA_Multimedia/Images/2024/04/Horsehead_...
|
| MIRI:
| https://www.esa.int/ESA_Multimedia/Images/2024/04/Horsehead_...
|
| Comparison:
| https://www.esa.int/ESA_Multimedia/Images/2024/04/Slider_Too...
| dylan604 wrote:
| I love that there are multiple sensors that can be compared to
| like this, but also love when the optical images from Hubble
| are compared as well.
|
| The images that combine all of the frequencies from Chandra
| X-rays, Hubble's optical, and now Webb's IR make for some truly
| fascinating images.
| GrumpyNl wrote:
| Is this image of what the eye would see or is it modified?
| Sharlin wrote:
| The JWST, as is well known, is a near and mid infrared
| telescope, its range (600 to 2850 nm) overlapping with
| human vision only a little bit in the deep red. So every
| single JWST image is necessarily in false color.
| dylan604 wrote:
| Even Hubble images are false color as well. It uses
| filters and then recombines them to RGB channels. People
| naturally ask what they would actually see, but they
| actually wouldn't see much of anything. Using a telescope
| to look at things, one only sees a black and white image.
| We've been shown so much from sci-fi with space ships
| showing nebulas and nova remnants out their view screens,
| but that' just not what one would see.
| dekhn wrote:
| No. A normal visible light telescope absolutely shows
| color. You can just point a DSLR with a zoom lens and no
| filters at the sky, take a picture of M42, and confirm
| that yourself.
| dylan604 wrote:
| I'm sorry, but the last time I checked a DSLR is not my
| eye. I have plenty of images from my telescope and
| various cameras. How you can conflate the 2 is beyond me.
| Comparing a long exposure from a digital sensor to what
| your eye can see is beyond bonkers and confusion of the
| topic at hand, or right in front of our eyes to keep it
| on subject
| dekhn wrote:
| Maybe I misread your statement "Using a telescope to look
| at things, one only sees a black and white image".
| Certainly you can see color when looking at planets
| (mars, jupiter, saturn). But more importantly: you can
| see M42 in color with a telescope and eyes, it doesn't
| need to be a camera or film. If your point is that it's
| hard for your retina to detect a rich color spectrum from
| distant objects without either magnification or time-
| averaging, sure, but that's not how your comment reads.
|
| Before you jump to "bonkers" maybe give the people you
| reply to some credit- I'm an amateur astronomer with
| facts at his disposal.
| dylan604 wrote:
| > Before you jump to "bonkers" maybe give the people you
| reply to some credit- I'm an amateur astronomer with
| facts at his disposal.
|
| As am I, and any time I use an eye piece, it is nothing
| but b&w for DSOs even for something as bright as Orion's
| Nebula. The spirit of the conversation is if people can
| see the true color the way images from large telescopes
| posted in articles like this. They cannot. You take the
| reaction from the average person that has only seen
| processed images after looking through a telescope for
| the first time, and they will almost always have a bit of
| disappointment in their voice. I have taken my scope to
| rooftop bars and let patrons look through at whatever can
| be seen at the time. I have yet to do this and not meet
| someone that's never looked through a telescope with
| their own eyes--which is the point of my effort.
| dekhn wrote:
| I understand. The way you wrote it it sounded like you
| were implying that the scope itself strips the color
| spectrum ("black and white") when really it's just the
| light is so faint that our cones don't really register
| color while our rods can easily register bright white
| light. (i work with weird people who don't like false
| color and instead look at the image as a series of
| monochromatic filtered images because you can see more
| detail that way)
|
| For demonstration, I always attach a DSLR to prime focus
| and display Live View.
| SiempreViernes wrote:
| Your comment about the colour fidelity of deep sky
| objects is _waay_ too sloppily written for you to get
| away with that tone!
|
| I mean, just look at what you wrote:
|
| > Using a telescope to look at things, one only sees a
| black and white image.
|
| as anyone who owns a telescope that can point at trees
| knows, you can _definitely_ "look at things" and see them
| in colour (assuming you have normal colour vision).
| dylan604 wrote:
| Yes, because in a thread about the JWST, then moving to
| backyard telescopes, we all naturally assume we're
| pointing them at trees.
| pmontra wrote:
| > Using a telescope to look at things, one only sees a
| black and white image.
|
| I remember seeing Jupiter in colors when looking at it
| from the backyard of a friend of mine.
|
| That telescope didn't have a motor and we were constantly
| chasing Jupiter manually. It stays inside the ocular only
| for a few seconds, then Earth points us into another
| direction.
| HumblyTossed wrote:
| Crazy how many galaxies are in that one photo (in the
| background).
| afterburner wrote:
| Number of stars in the Milky Way: 100 billion
|
| Number of galaxies in the universe: 200 billion to 2,000
| billion
| markus_zhang wrote:
| Is 2,000 billion some theoretical limit or something else?
| Thanks.
| sandworm101 wrote:
| Yes. Take the age of the universe, multiple by the rate
| of expansion to get the total size of the universe, then
| multiple by the average density of galaxies in the
| observable universe. There are some further
| complications, but at the root it is basic algebra.
| worldsayshi wrote:
| Is that really the way to see it? As I understand it, the
| Big Bang didn't happen in "one place". The Universe is
| expanding from an compressed state - the Big Bang state.
| But there is no center point. We can only see that
| there's expansion but it's not from a single point. The
| only known "center point" is us. And the only reason it's
| a center point is because we can only see as far away as
| light has traveled since the Big Bang.
| reactordev wrote:
| This theory of multiple points supports the big ring and
| other structures outside the "this shouldn't exist"
| bubble. The bubble is the Big Bang + rate of expansion.
| It was thought that there was nothing outside of the
| farthest point... but there is!
| pdonis wrote:
| _> As I understand it, the Big Bang didn 't happen in
| "one place"...there is no center point._
|
| That is correct. The only tenable answer to "where did
| the Big Bang take place" is "everywhere".
| injidup wrote:
| So if the universe has a _size_ then what do you see if
| you are on the edge of it? Do you see stars to the left
| and nothing to the right? I mean given the speed of light
| and the age of the universe and the rate of expansion
| there are regions inaccessible to us but that doesn 't
| quite mean the universe has a finite size.
| dragonwriter wrote:
| Finite size doesn't require an edge. Consider the surface
| of a balloon for a 2-D case (or the perimeter of a
| sphere, for a 1-D case): it has finite extent, but no
| edge.
| lupire wrote:
| It has a surface, though, which is what PP was asking
| about.An answer to the question is, yes, nesr the
| edge/face, one side is dark. But relativity and expansion
| makes the situation a bit more complicated.
| dotnet00 wrote:
| The _observable_ universe has a size, the cosmic
| microwave background is what we 'see' at the 'edge' in
| terms of photons (~400k years after the big bang). We
| could see further if we could map out the gravitational
| wave or neutrino backgrounds (1 sec after the big bang).
|
| But for now we can't really say if the universe in its
| entirety has a finite size.
| mvkel wrote:
| Fascinating. Do you think it's possible that we can map
| these out in the next 50 years?
| dotnet00 wrote:
| For the gravitational wave background, maybe with LISA we
| might be able to get a glimpse, but the neutrino
| background seems like it'd take some truly unprecedented
| breakthroughs in our ability to detect neutrinos to have
| any chance of mapping it out.
| mvkel wrote:
| Funny, in reading up on both, I had higher hopes for the
| gravitational waves.
|
| It seems like GWB is a superposition of infinite
| overlapping waves that would be impossible to single out
| and "unwind" in order to form a map.
|
| And big bang neutrinos are very weak, which makes them
| undetectable. My assumption was we'd need a breakthrough
| in measurement sensitivity but is there more to it?
| datameta wrote:
| Naive thought - can a subsurface detector on the moon
| serve as an ultracold shielded scenario?
| causal wrote:
| Replying to the other replies here - this regards the
| observable universe. Speed of light limits and all that.
| Of course we have no reason to believe the universe just
| stops at the point where we happen to lack the ability to
| observe.
| sandworm101 wrote:
| Well, no. The density in the observed universe is used to
| extrapolate the number of galaxies in the non-observed
| universe. The size of that universe is extrapolated from
| the rate of expansion and the time since the big bang.
|
| The size and shape of the observable universe also
| changes. A moving observer, say someone doing 30% of
| lightspeed, will see further in one direction than
| another. Accelerate quickly enough and the "dark" side of
| your custom observable universe might catch up with you,
| causing all sorts of havoc.
|
| https://en.wikipedia.org/wiki/Unruh_effect
| layer8 wrote:
| As far as we know, the total universe may have infinite
| size, and thus contain infinitely many galaxies.
| an-honest-moose wrote:
| That doesn't necessarily follow - the universe can be
| infinite in size, but contain a finite amount of matter.
| layer8 wrote:
| True, I was keeping the reasoning about the average
| density. A homogeneous universe is still the null
| hypothesis.
| pdonis wrote:
| Not the universe we observe, no. There is no valid model
| in GR that has this property and matches our observations
| of the universe as a whole. Models with a finite amount
| of matter surrounded by an infinite region of vacuum
| exist in GR, but they are not homogeneous and isotropic
| on large scales, while our observations indicate that our
| universe is.
| nilkn wrote:
| You're assuming that space was compressed into a single
| point at the Big Bang. However, this is not implied by
| the Big Bang or cosmology. All we can truly infer is that
| the universe was very hot and dense and that spacetime
| experienced rapid expansion. We do not know the size,
| extent, or shape of space at that time, and we don't even
| know how much matter and energy were present. We only
| have a notion of the density.
| causal wrote:
| Yeah this is a difficult concept, and I think the way the
| big bang is commonly portrayed in media often leads to
| this misconception of the big bang as starting at a point
| in space rather than a density.
|
| I uncovered this for myself when asking, "where is that
| point now?" and discovering it was never a point at all,
| space is expanding from all points simultaneously.
| sandworm101 wrote:
| The easy answer to the hard concept is that the big bang
| is not the increase in size of a thing. It is an increase
| in dimensions, including time. Our notions of size, of
| dimension, might not exist outside the bubble. We would
| therefore never perceive an edge, but that doesn't mean
| that one does not exist nor that there may be a finite
| size.
| Baeocystin wrote:
| I explain it to folks as if one was trying to go further
| south than the south pole. There's nothing physically
| impeding you; it's simply that once on the pole, all
| directions are north.
| regularfry wrote:
| Even that's not especially easy, because you then need to
| deal with "if the dimensions themselves are changing, why
| aren't protons the size of planets?"
| sandworm101 wrote:
| We may not know the exact size at the start, but we know
| it was infinitesimally smaller than it is today. So the
| size of the initial universe isn't a big factor in the
| equations about how big it likely is today. Weather it
| started as a few centimeters across or a few thousand
| light years across, both are functionally zero compared
| to the current size.
| nilkn wrote:
| We don't know that, though. Consider an evolution of a
| flat coordinate plane given by (x,y) -> (e^t * x, e^t *
| y). This process can run forever and has the property
| that all points appear to move away from all other points
| through time, yet the size of the plane never changes.
|
| It's better to think of the Big Bang as describing a
| point in time rather than a point in space.
| mynameishere wrote:
| Does anyone know why wolframalpha is plotting this with
| cute little arrows?
|
| https://www.wolframalpha.com/input?i=plot+%28x%2Cy%29+%3D
| +%2...
| itishappy wrote:
| It's a vector field! It has 2 dimensional inputs and 2
| dimensional outputs, so it doesn't fit on your
| traditional graph. f(x,y) = (c * x, c *
| y) f(x,y) = c * (x,y) f(P) = c * P
|
| If you give some thought to what `c` is doing to each
| point of your plane (start with the origin!), I bet that
| graph might make a bit more sense. :)
| thaumasiotes wrote:
| > Consider an evolution of a flat coordinate plane given
| by (x,y) -> (e^t * x, e^t * y). This process can run
| forever and has the property that all points appear to
| move away from all other points through time, yet the
| size of the plane never changes.
|
| What do you mean by that last claim? Any observable
| region is bigger at later times than it is at earlier
| times. The reason all points always appear to be moving
| away from all other points is that that is in fact
| happening.
|
| What's the significance of claiming that the size of the
| infinite plane never changes? It's just as true that if
| you start with the unit interval [0, 1] and let it evolve
| under the transformation f(x) = tx, the size of the
| interval will never change -- every interval calculated
| at any point in time will be in perfect 1:1
| correspondence with the original (except at t=0). But
| this doesn't mean that the measured length of the
| interval at different times isn't changing; it is.
| BearOso wrote:
| We know the observable universe was part of the big bang
| and is expanding, maybe even _because_ we 're observing
| it. We have no concept of whether that dense spot was all
| there was, and there are a whole slew of other caveats,
| so it could even be orders of magnitude larger.
|
| Our current knowledge is functionally zero in the grand
| scheme of things.
| irjustin wrote:
| > Well, no. The density in the observed universe is used
| to extrapolate the number of galaxies in the non-observed
| universe. The size of that universe is extrapolated from
| the rate of expansion and the time since the big bang.
|
| > We may not know the exact size at the start, but we
| know it was infinitesimally smaller than it is today. So
| the size of the initial universe isn't a big factor in
| the equations about how big it likely is today. Weather
| it started as a few centimeters across or a few thousand
| light years across, both are functionally zero compared
| to the current size.
|
| Most things you're saying are correctly rooted except for
| what's beyond the observable universe. I'm not sure why
| the staunch belief that you can confidently claim this.
| To be clear, you aren't provably wrong - likewise not
| provably right either.
|
| The replies to you are just fine, they represent a
| significant portion of the scientific community that says
| our universe is likely infinitely big and that, possibly,
| the big bang was infinitely small, yet still, still
| infinitely large. An infinite expanding into infinite
| still results not knowing what's out there.
|
| PBS Space time talks about it in terms of "scale
| factor"[0] instead of absolute diameter.
|
| Still, these are all debatable theories, so your take
| _could_ be valid, but generally, it points infinitely
| large.
|
| [0] https://youtu.be/K8gV05nS7mc?t=271
| pdonis wrote:
| _> The density in the observed universe is used to
| extrapolate the number of galaxies in the non-observed
| universe._
|
| As has already been pointed out, our best current model
| of our universe is that it is spatially infinite. That
| means an infinite number of galaxies.
|
| The finite galaxy numbers that astronomers give _are_ for
| the observable universe.
|
| _> The size and shape of the observable universe also
| changes._
|
| Not the way you are describing, no. The observable
| universe does increase in size as time goes on, because
| there is more time for light to travel so the light we
| see can come from objects further distant. Its shape,
| however, does not change.
|
| A good reference is Davis & Lineweaver's 2003 paper:
|
| https://arxiv.org/abs/astro-ph/0310808
|
| _> A moving observer, say someone doing 30% of
| lightspeed, will see further in one direction than
| another._
|
| I don't know where you're getting this from. What part of
| the universe you can observe from a given point does not
| depend on your state of motion.
|
| _> Accelerate quickly enough and the "dark" side of
| your custom observable universe might catch up with you,
| causing all sorts of havoc._
|
| This is nonsense. The Unruh effect is (a) nothing like
| what you are describing, and (b) irrelevant to this
| discussion anyway, since the Unruh effect only applies to
| objects which have nonzero proper acceleration, which is
| not the case for any galaxies, stars, or planets in the
| universe.
| Nevermark wrote:
| > The density in the observed universe is used to
| extrapolate the number of galaxies in the non-observed
| universe.
|
| The unobserved universe is likely to be many orders of
| magnitude larger than the observed universe. It is
| possible that it is unimaginably larger.
|
| Technically, it is possible that the unobserved universe
| is infinite, however whether that is a credible option
| depends on individual scientists informed intuitions. We
| simply have no experimental or theoretical evidence
| either way at this point.
|
| So there is no estimate of how many galaxies there are in
| the universe in toto.
| reactordev wrote:
| What about the big ring [0]? Or other mega structures of
| galaxies outside that "bubble"?
|
| [0] https://en.m.wikipedia.org/wiki/Big_Ring
| mvkel wrote:
| Isn't the rate of the expansion of the universe
| increasing?
|
| And that assumes the observable universe is homogeneous,
| which it isn't
| pdonis wrote:
| _> Isn 't the rate of the expansion of the universe
| increasing?_
|
| It is now, but up until a few billion years ago, it
| wasn't, it was decreasing. Many of the objects we
| currently see are far enough away that the light we are
| now seeing from them was emitted while the universe's
| expansion was still decelerating.
|
| _> that assumes the observable universe is homogeneous,
| which it isn 't_
|
| No, the models cosmologists use do not assume the
| universe is homogeneous period. They only assume it is
| homogeneous on average, on large distance scales (roughly
| scales larger than the size of the largest galaxy
| clusters).
| glenstein wrote:
| >Take the age of the universe, multiple by the rate of
| expansion to get the total size of the universe, then
| multiple by the average density of galaxies in the
| observable universe
|
| My understanding is that, at the largest scales, clusters
| of galaxies are organized along a series of
| gravitationally bound filaments, sometimes called the
| cosmic web.
|
| So they aren't distributed like random noise, but more
| like a web. I have no reason to think this changes
| anything about calculating average densities, but it is
| notable that there's the general density but probably a
| significantly different density within that structure.
| layer8 wrote:
| *observable universe
| bufferoverflow wrote:
| 100 billion is the low end estimate for our galaxy.
|
| 400 billion is the high end.
| ridgeguy wrote:
| A few years ago, I calculated that there are approximately
| one Mole (6e23) of stars in the visible universe. That was a
| fun result.
| m463 wrote:
| We are probably looking at galaxies when we look at some
| stars and have no idea how many turtles deep things go.
| HenryBemis wrote:
| And when 'zooming in' and seeing the top 2/3 of the photo (http
| s://www.esa.int/var/esa/storage/images/esa_multimedia/im...) I
| am super amazed that all these small discs showing are
| galaxies. GALAXIES (sorry for the caps).
|
| How tiny are we (Humans, Earth, Solar system)... less than a
| speck of dust in the Sahara.
|
| I used to look up in space when I was growing up and there
| wasn't any light pollution to the small town I was growing up
| in. At some point I think I started suffering from 'cosmic
| horror'. In later years I would pay attention only to the moon,
| and that reduced my stress significantly.
|
| Nowadays (like in this bit of news, with photos) when I stick
| to the small photo in an article, I feel ok. When I see it in
| full size and I zoom in, and I realize that "sh*t! these
| 5-10-50 tiny white marks are GALAXIES.. and I have to change
| topics/tabs to keep the cosmic horror at bay.
| chrisweekly wrote:
| Interesting. I've also always had a visceral response to
| particularly clear night skies - but it's only ever been a
| profoundly positive feeling. It kind of erases the idea that
| my "problems" have any significance at all.
| lm28469 wrote:
| The loss of dark skies is so painful, maybe the worst thing
| modern life brought to us. I remember laying in the grass
| with my grandma looking at the stars for hours, she would
| tell me how the whole village gathered around the only TV
| they had to watch the moon landing live, about sputnik,
| galaxies, satellites, &c. there aren't many things as
| mesmerising, maybe watching a fire or the ocean waves, but
| it doesn't trigger the same emotions in me.
|
| I don't travel much but when I go to remote areas star
| gazing is up there on my list of things to do; watch the
| stars until you're about to pass out from hypothermia, go
| back inside, make some tea, enjoy the fireplace, forget
| about the daily (non) problems, it never gets old
| syspec wrote:
| Experience that all the time with the same imagery, with the
| same amazement / horror combination.
|
| What's more amazing is when you share this fact to most
| people "did you know each dot here is a GALAXY, not a star!"
| they go "heh... interesting" and shrug.
|
| For some reason that makes the whole thing even crazier to me
| dotnet00 wrote:
| I think it just doesn't really click for people most of the
| time. Eg for my mom no amount of showing science pics and
| explaining the scale of the distances conveyed things, it
| only really clicked when Jupiter became visible in the
| night sky as a particularly bright and large point of light
| which caught her interest, and when we moved to somewhere
| dark enough that the galactic plane was faintly noticeable.
| HenryBemis wrote:
| Yeah, I haven't seen the milky way with naked eye for a
| few years.
| Koshkin wrote:
| And yet, it is the atomic nucleus that is one of the most
| complex objects in nature.
| datameta wrote:
| Complex in terms of our attempts to fully define it, or?
| jjbinx007 wrote:
| Cosmic horror is a good one. I've only seen the Milky Way
| with my own eyes a couple of times and the last time gave me
| an existential cosmic horror too.
|
| I went to sleep thinking about the unignitable size and age
| of what's all around us in every direction, but particularly
| that I had just looked at our own galaxy... a galaxy that has
| been there for billions of years, has always been there my
| entire and is there right now and there's only this tiny
| invisible thin bit of atmosphere separating us from it.
|
| Then I thought about the fact tha our solar system is
| orbiting it right now, and we're orbiting the sun on an
| invisible track, and the moon orbits us on its own invisible
| track too.
|
| That's quite a lot to deal with when you only woke up for a
| pee in the middle of a night in a camping holiday in Wales.
| tobias2014 wrote:
| To fuel your cosmic horror: Some of the dots may even be
| galaxy clusters
| HenryBemis wrote:
| Hahahahaha cheers, I had just forgotten about this and was
| going to sleep, but hey, what's a couple more hours of
| freaking out! :)
| nick238 wrote:
| I kinda had an out-of-body experience when watching the
| Kurzgesagt video on The Largest Black Hole in the Universe.
| https://www.youtube.com/watch?v=0FH9cgRhQ-k
|
| Watching the zoom-out to picture ultra-massive black holes is
| surreal.
| bloopernova wrote:
| Gorgeous and upsetting that I'll never be able to visit it.
|
| 13 billion years before me, potentially trillions of years after
| me. Seems like such a waste of the spark of awareness that I
| can't take that awareness and experience the galaxy in all its
| glory.
| dylan604 wrote:
| I have reservations for the restaurant at the end of the
| universe.
| latchkey wrote:
| There's a frood who really knows where his towel is.
| layer8 wrote:
| If you look closely at the kitchen in the background, it's
| all frozen microwave food.
| dylan604 wrote:
| So it's an Applebees?
| itg wrote:
| Isn't a nebula a cloud of dust? I'm not sure how dense it gets,
| but would someone even notice if they were inside of the
| nebula?
| accrual wrote:
| I was thinking this too. These cosmic objects look solid from
| afar, but they could be just slightly more dense than the
| surrounding space on average.
| lisper wrote:
| > Isn't a nebula a cloud of dust?
|
| Yes.
|
| > I'm not sure how dense it gets, but would someone even
| notice if they were inside of the nebula?
|
| https://physics.stackexchange.com/questions/26326/how-
| dense-...
|
| (Google is your friend.)
| denton-scratch wrote:
| > Isn't a nebula a cloud of dust?
|
| I think "dust" is a term of art in astronomy. A cloud of
| rocks the size of cars could be dust. I suppose that if you
| can't resolve the particles, then it's dust.
|
| If I look at this part of the Orion Nebula, it looks opaque;
| I can't see what's behind it. So I guess if I were in the
| middle of the nebula, then I wouldn't be able to see out of
| it. There are many stars in the nebula that are not visible
| (in visible light).
|
| So I suppose that what you'd see would depend on where in the
| nebula you were sitting; if you were near a star, the dust
| would be illuminated, and the sky would be bright. If you
| were not near a star, presumably the sky would be dark, and
| you'd look up and see nothing, like the inhabitants of the
| planet Cricket.
| dheera wrote:
| There are multiple types of nebulae. Absorption nebula (or
| dark nebula) and reflection nebula are clouds of "dust" (more
| likely lots of rocks).
|
| There are also emission nebula which are clouds of ionized
| gases that emit light.
|
| The horsehead nebula is an absorption nebula that sits in
| front of light-emitting emission nebula. It's fairly easy to
| image the horsehead with a star tracker and DSLR, though not
| to this level of detail.
| whartung wrote:
| > Seems like such a waste of the spark of awareness that I
| can't take that awareness and experience the galaxy in all its
| glory.
|
| But you just did. That's what we're doing.
|
| The horse head part that we see is 3x4 LY in size. If you
| wanted to experience that horse head like you would, say, a
| mountain -- just a large, field of view dominating visage. You
| would need to be about 20+ Lightyears away from it.
|
| I don't know how bright the nebula is, but after 20 lightyears,
| I don't know how much the human eye could perceive it. And,
| likely, by the time you got close enough to actually see it, it
| may well just be a hazy cloud with no definition, since you'd
| be so close.
|
| Things like these may only be able to be experienced by us
| through artificial means. Through embellishment and
| enhancement.
|
| You can go and buy a "smart telescope" today that you can push
| a button, and point it at any of the "local" nebulas or other
| bright objects in the sky. Yet, if you look through the
| eyepiece, you won't see much. Even with magnification, it's a
| gray, fuzzy blob. The smart telescope will automatically
| capture more light, through longer exposures, and create a
| composite image with better definition and detail. Even with
| magnification, we can not experience those objects directly.
|
| Astronomy, for me, is most "personal" with a pair of
| binoculars, particular a pair of stabilized binoculars. A
| mundane pair will open up the sky in a breathtaking way.
| Because it's more "real". It's not a picture on screen, and it
| wide and sweeping and huge.
|
| But you can't really get those really fun Milky Way photos
| folks are making, not with binoculars. You CAN see the Milky
| Way under dark skies, but not like those photo capture them.
|
| So, simply, "you can shut up. Stop typing now. Really", you may
| well have just experience the nebula as best as it can be done
| right now. Run that video on a huge TV in a dark room, it will
| help. Maybe see if any of this stuff is coming to an IMAX
| theater near you.
| holtkam2 wrote:
| Why will there only be trillions of years after you? Why not
| quadrillions? Couldn't we just pick an arbitrary number up to
| the largest variety of infinity?
| kouru225 wrote:
| I don't think visiting it would be very interesting. It's a
| giant dust cloud that would probably be unnoticeable from any
| close perspective.
| anigbrowl wrote:
| Go camping and bring some friends and psychedelics, it'll help
| you get over your FOMO
| system2 wrote:
| Depending on the person this can go both ways.
| SoftTalker wrote:
| It's amazing to me how an interstellar-sized cloud formation
| looks very much like a cloud formation in the sky on earth.
| Maxion wrote:
| Nature is very fractal, the same pattern occurs on multiple
| levels. You even see the same thing in human constructs.
| usrusr wrote:
| But what's giving it it's seemingly clear cutoff boundary? I
| have trouble imagining anything in the nothingness of space
| taking the role of the forces that shape our atmospheric
| clouds. It feels a bit as if it was some arbitrary artistic
| decision like that 2001 slit scan or the Solaris ocean. Then
| on the other hand of course it's amongst the few most
| "artistic" ones picked from all those super tiny projection
| viewports we have taken from the sphere of view directions,
| so perhaps we should not be all that surprised. It's not
| quite the level of unlikely discovering a planet populated by
| mattresses would be.
| digging wrote:
| There are lots of forces at play! The article mentions some
| of them. Structures are shaped not just by gravity, but by
| electromagnetism, starlight, supernovae, and more.
| AbraKdabra wrote:
| The amount of faint Galaxies in the final image is absolutely
| astounding, there's no way we are alone.
| pfdietz wrote:
| Yeah, that's a non sequitur.
| r00fus wrote:
| Lightcone theory [1] explains to us how we're likely prevented
| from ever actually "meeting" the others.
|
| [1] https://en.wikipedia.org/wiki/Light_cone
| dangoodmanUT wrote:
| god look at all those itty bitty galaxies behind it... so
| exciting
| sizzzzlerz wrote:
| My god, it's full of galaxies!
| pictureofabear wrote:
| One of the greatest things about Webb's photography is that
| *every* image is a deep-field image.
| Ninjinka wrote:
| Unprecedented is quickly becoming the most overused adjective
| digging wrote:
| We keep doing new things, though.
| pyinstallwoes wrote:
| How much of the pictures in the article are processed? What does
| the unprocessed photo look like?
| BurningFrog wrote:
| All of the Webb observations are done in infrared light, which
| is invisible to us humans.
|
| So the smartass answer is that it looks all black :)
| lolc wrote:
| I guess the unprocessed "photos" look like multidimensional
| arrays of floating point numbers. Nothing a human could
| appreciate. The interesting question is _how_ they are
| processed.
| coldpie wrote:
| The paper contains links to the raw data, descriptions of the
| data transformations they did, and links to some github
| projects, but it's all way over my head :)
| https://www.aanda.org/articles/aa/pdf/forth/aa49198-24.pdf
| npteljes wrote:
| It's fully processed. The Webb sees in infrared (0.6-28.3 mm),
| and the human eye sees in visible spectrum, which is like
| 380,000 - 750,000 mm, so not the same ballpark at all. I
| believe that the nebula cannot be seen with the naked eye at
| all. It can be photographed though, but it only becomes visible
| after combining and processing many long exposures.
| devsda wrote:
| That's an incredibly detailed image.
|
| Every single time I see one of these amazing space pics, it's
| hard not to get all philosophical and wonder about the size of
| space & time on cosmic scale, how small our earth is and how
| insignificant our _regular_ problems are.
|
| I don't care if I don't get to see flying cars or AGI in my
| lifetime but I will be very disappointed if our knowledge of
| space remains more or less the same as today without much
| progress.
|
| Edit: typo
| the_af wrote:
| > _it 's hard not to get all philisophical and wonder about the
| size of space & time on cosmic scale_
|
| Indeed!
|
| Never a bad time to re-watch Cosmos and (in my opinion) the
| awesome sequel(s) by Neil de Grasse Tyson. Is it weird to admit
| I even choke up during some of the episodes?
|
| (As an aside, why is it so hard to find the sequels to Cosmos
| in any streaming service. In my country it's not on Netflix,
| Disney+, Apple, HBO/Max, Star+, Prime Video. What the hell...?
| I just want to re-watch the damned thing and I don't own a Blu-
| ray player. Do I have to pirate the stuff?)
| nsbk wrote:
| You are not alone
| bjelkeman-again wrote:
| We wanted Spotify for video, we got Netflix, Disney+, Apple,
| HBO/Max, Star+, Prime Video, and your local thing too. And
| they still haven't got what you want to watch. /sigh
| xandrius wrote:
| You gave it a fair shot, go ahead and come join us at the bay
| where the grass is green, the videos full HD and nobody wants
| your money (just your soul).
| seabass-labrax wrote:
| Neil de Grasse Tyson is still on my 'to watch' list, but you
| may be interested in Brian Cox's 'Wonders of the Solar System
| / Universe' series. From what I've heard, Brian Cox is
| something of the British equivalent of Tyson. 'Wonders-' is a
| beautifully shot series that is both educational and remains
| impressive over a decade on (2010-2011).
|
| The only thing that might be disappointing if you're already
| into astrophysics is that it's rather dumbed-down compared to
| his books, which are more earnest, closer perhaps in style to
| Feynman's Lectures.
| the_af wrote:
| Wow, never even heard of Brian Cox! Will find this series
| you mention. Thanks for the recommendation.
|
| I'm not a physicist of any kind so I'm ok at the "science
| divulgation" level.
| antod wrote:
| I really like Brian Cox, but I do really wish he'd aim his
| content a bit higher and pack a bit more information into
| it. I hesitate to use "dumbed down" though (maybe I would
| if I didn't like him so much), more like it's just a bit
| too laid back and slow like it's aimed at people not really
| paying attention.
| WorldMaker wrote:
| I feel like Brian Cox over-corrected as his career has
| progressed further and further into the "science
| edutainer" career. His early books were fascinating
| glimpses into String Theory and M-Theory and often got
| criticized for being too dense.
|
| To be fair, a similar criticism is often levied at Niel
| deGrasse Tyson as well that his modern persona is too
| laid back and slow and aimed at people not really paying
| attention, but some of his early astrophysics stuff was
| dense and cool and you still get those glimpses when he
| is advocating for astrophysics content.
|
| (Relatedly, it's a part of why I respect Bill Nye's late
| career attempts at aging his attempted shows up and
| advocating for things like climate science in them, even
| if those messages and content density sometimes sadly
| falls to bad or mixed reviews. It is impressive to see
| him trying.)
| the_af wrote:
| I think the divulgator role is necessary though. I like
| Neil's laid back & slow persona. He communicates for
| effect, glossing over details which would overwhelm
| casual audiences. He is emotional, grave or funny as
| needed. He simplifies where it's needed for a 40 minute
| episode of a show aimed at general audiences (like
| myself!).
|
| I feel the role of science communicators/eduitaners such
| as these is to spark an interest in the topic. You can
| later go for details elsewhere, or even pursue a career
| in science.
| WorldMaker wrote:
| Yeah, I agree there is a great utility to it, and it can
| be of great benefit. I also still think that it feels a
| useful criticism to keep mentioning as well because
| there's that always balance to strike in the huge wide
| spectrum between "mainstream and fluffy and almost void
| of content" and "deep and interesting but hard to follow
| and more clearly for a niche audience.
|
| It's a bit of a hysteresis, right, of constantly trying
| to fight for that "perfect" (nonexistent?) fit of strong
| content to largest audience. Like with most science
| itself, you experiment with some content, use the reviews
| and criticism you get back to compensate for the next
| content. When I accuse Brian Cox or NdGT "over-
| compensating" a little to the broad it's not that I don't
| think they are doing the right thing, it's that I hope
| their next hysteresis swing might go a bit denser _again_
| and maybe criticism like mine will be useful if either of
| them read HN.
|
| Similarly, I respect Bill Nye's attempts so much
| _because_ it seems (from the outside, from mixed reviews
| I 've read, from other people talking about the shows) to
| be, if not "failing" then certainly not as successful as
| they could be. As science reminds us, failed experiments
| are useful too, and I don't necessarily want people to
| believe in the boring null hypothesis that "People don't
| want harder science discussions" and I don't want for
| people like Bill Nye to give up on trying to broach the
| hard topics (like Climate Change and more science that
| should be mainstream but is fighting disinformation
| and/or disinterest). (Not that I think Bill himself would
| give up, but that it might discourage people trying to
| follow in Bill's footsteps.) I would love to see more of
| these "edutainers" trying to do the hard stuff more of
| the time, get a wilder balance/mix. I want to see more
| stuff in general in the spectrum as a whole. I don't
| think "celebrity" is necessarily zero sum and that these
| "edutainers" are competing among each other for the same
| audiences, but there does seem to be some scarcity
| factors for "celebrity scientist" at play to account for.
| WorldMaker wrote:
| It should be one of the things that Disney owns outright
| today (from having bought some but not all of Fox/News Corp),
| so Disney+ is the natural home, but that version of Cosmos
| was a very expensive show so between the "Disney Vault" and
| Disney again remembering they can get revenue from lending
| shows to other services it does seem to be off Disney+ for
| the moment.
|
| JustWatch says it is streaming on ad-supported Free service
| Tubi in the US right now: https://www.justwatch.com/us/tv-
| show/cosmos-a-spacetime-odys...
|
| (JustWatch is a too useful service at this point in the
| Streaming Wars to figure out where shows and movies currently
| are. I am getting to point of buying more Blu-Rays again,
| though, because there are too many services and many of the
| ad-supported ones like Tubi and Pluto are sometimes really
| obnoxious, and some of the paid services I have strong
| reasons I don't want to pay for them. I certainly have
| friends that have gone back to piracy, and it does sound more
| tempting as the Streaming Wars get worse.)
| the_af wrote:
| Thanks, JustWatch is indeed very useful!
|
| I'm not in the US so Tubi doesn't work for me. Apparently
| none of the Cosmos series (original or the two sequels) is
| available in my country. Not even to buy.
|
| I'm so thrilled! I cannot wait to NOT watch this anywhere
| legally!
|
| Oh well, to the Bay it is.
| markus_zhang wrote:
| That always makes me want to ditch whatever I'm doing and
| switching gear to hiking, coding and studying Mathematics and
| Physics.
|
| Bitter realization at the end, of course.
| layer8 wrote:
| We are lucky that we live in a sweet-spot era where the
| universe is old enough that we have 13 billion years to look
| back on, but young enough that all the galaxies haven't receded
| behind the cosmic horizon yet due to the accelerated expansion
| of the universe. In some billion years, intelligent beings will
| only have historic records, if anything at all, to look back to
| how the observable universe used to be filled with billions of
| galaxies.
| deanCommie wrote:
| I don't understand people that aren't filled with dread with
| this concept.
|
| And I understand why so many humans fall back to something
| like religion to cope. It's the only way it seems to become
| complacent with our role in the cosmic horror.
|
| I know all the intellectual arguments for optimistic
| nihilism. I vote in elections even though my "one vote"
| doesn't matter amongst millions, and in some degree my single
| human life is the same on a timescale of (hopefully)
| trillions of humans by the time we get to the point of
| worrying about the receding observable universe.
|
| And yet...
| layer8 wrote:
| The change is too slow for anyone to be personally affected
| by it. Besides, the universe as such is devoid of any
| meaning; meaning is only something that we create
| internally. The fact that we dread voids and emptiness is
| also a result of evolutionary needs, there is no "dread"
| outside of us.
| mensetmanusman wrote:
| Humans are the universe defining meaning.
| timeon wrote:
| People create various stories just to escape concept of
| void. But if one does not seek those lies, there is no need
| for nihilism. Because even if our consciousness was not
| relevant - it is only thing we have. It is relevant to us.
| It is us till we meet the void.
| rpigab wrote:
| What if the only place where intelligent life was ever
| possible in the universe is being actively made impossible to
| live in by intelligent beings, which means after they're gone
| extinct, there'll be no intelligent beings to appreciate its
| beauty?
| layer8 wrote:
| That seems a quite likely outcome to me. On the positive
| side, once it happens, there will be no one who would mourn
| it.
| skilled wrote:
| Buddhism is deeply rooted in reincarnation and the
| progression of a common person to an enlightened being
| through different ranks over the span of multiple
| lifetimes.
|
| I am pretty sure there is a dimension of life that we have
| yet to discover and learn about. And for the time being
| Buddhism is the only "religion" that openly discusses this
| progression.
|
| Hinduism has the same but in my experience it's a lot more
| reserved. Bali is a great example of this (which has a
| strong Hinduism foundation), of how you can create
| "paradise on Earth" and yet 99.99% of tourist's don't ever
| encounter the root of that paradise.
|
| Humans will learn the full extent of life long before they
| go extinct.
| Nevermark wrote:
| I think any view of life consistent with its emergence by
| evolution isn't consistent with reincarnation, or
| certainly doesn't support it.
|
| But given the universe in total may be unimaginably
| larger than our observable universe, and the total
| universe may well be an insignificant feature of an
| unimaginably larger reality, its quite possible that
| versions of us appear in a fractal-like way, over and
| over across reality.
|
| Also, given the many worlds interpretation of quantum
| mechanics, which is the most basic (Occam's razor)
| interpretation of the equations, we are constantly
| spinning off a foam of combinatory alternatives of
| ourselves and everything around us, because the particles
| that make us up are doing that. So we live many lives,
| and even when we die in one perceived timeline, other
| versions of ourselves continue their journey.
|
| Both of those are scientifically plausible, especially
| the second - which many scientists already believe to be
| true.
|
| Although they sensibly tend to focus on interpretation at
| the particle level, avoiding the hype and wishful
| mysticism that would tend to crop up around its
| implications for us as individuals. Too many imaginative
| people and popularizers have a tendency to jump from
| actual equations/constraints they don't understand, to
| non-scientific psychologically motivated "implications"
| and ideologies. Quantum mechanics has been abused enough
| that way.
| skilled wrote:
| The easiest way to test the theory is to go into the
| unknown and find out for yourself. You can walk into life
| situations with a predisposition (which is a useful skill
| to have) and then see the feedback that you get in
| return.
|
| By and large, to really have success with this is to
| learn meditation (not master it by any means), because
| even basic meditation will naturally provide insight that
| is outside of the scope of the mental framework you are
| accustomed to as a mind.
|
| Even in science, there is a lot of focus on what happens
| to the person on a physical and a mental level, but
| little on what happens outside of it, which can only be
| learned by being quiet/still.
|
| I like your reply and it is balanced, and I am not sure
| that I could reply to it in any other way than I did now.
| My personal experiences transcend a lot of such
| discussion, even what I am saying myself, but those are
| the elements of being human, being bound by _something_.
|
| I think manipulation of elements (for example) will be
| considered as a very primitive thing in the grand scheme
| of evolution!
| Nevermark wrote:
| I am not exactly sure what you are saying! :)
|
| My response is staying with science, which just means
| staying with evidence and reasoning that avoids our
| unbounded ability to fool ourselves. I.e. repeatable
| experiments by others, tested model predictions,
| mathematical and statistical checks, etc.
|
| That is all science and math are. An accumulation of
| tools and systems that improve the reliability of our
| thinking. They increasingly help us mitigate our
| exceptional talent for fooling ourselves.
|
| If we find another way to "know", it will get included
| into science too.
|
| I am a big believer that our personal experience and
| relationship with life is improved by meditation, staring
| by learning to quiet our minds and focus/refocus on one
| simple thing at a time (breathing for instance, or
| nothing). Then use our ability to focus to mindfully
| listen to our bodies, then our feelings, then our
| beliefs, our values, our situations, finally what it all
| means.
|
| But our minds/brains don't internally track providence of
| information. What is real and beyond us, vs. what we
| imagine or want. It is all mixed up in our heads, thus
| the ease with which we trick ourselfs, and others.
|
| I am a big believer in imagination, to the sky and beyond
| anything we see. But the very unboundedness of
| imagination is why just because we can imagine something,
| and it seems right, fulfills some deep balance, and seems
| vivid, desirable, and makes clear sense that must be
| true, ... that doesn't actually make it true, real, or
| coherent, not even a little bit.
|
| > I think manipulation of elements (for example) will be
| considered as a very primitive thing in the grand scheme
| of evolution!
|
| Evolution created multicellular creatures, nervous
| systems, and brains, which in turn have created a
| species/society that is actively searching for knowledge
| and putting it to work for survival at higher orders of
| organization. I.e. science, economics, politics,
| technology, etc. Limited resources (at any given time)
| continue to drive us to solve new problems and learn
| more, to continue surviving even as we complicate and
| expand the environment we survive in.
|
| So in that sense, life is already moving past biological
| chemistry into other substrates, and we are already
| learning to harness the arrangement of atoms to go
| further. And eventually, perhaps, harness the fine
| structure of space-time, and beyond.
| mistermann wrote:
| > Although they sensibly tend to focus on interpretation
| at the particle level, avoiding the hype and wishful
| mysticism that would tend to crop up around its
| implications for us as individuals.
|
| Is this yet another one of those scientific facts that
| does not require a proof?
|
| > Too many imaginative people and popularizers have a
| tendency to jump from actual equations/constraints they
| don't understand, to non-scientific psychologically
| motivated "implications" and ideologies.
|
| Similarly, too many imaginative people who lack adequate
| depth in epistemology and non-binary logic like to
| practice both on the internet as if they know what
| they're doing. And the beauty of it is: if the minds of
| the population have been adequately conditioned, no one
| notices.
|
| But wait, there's even more Oracle level soothsaying of
| _the unknowable_ below:
|
| -------------
|
| My response is staying with science, which just means
| staying with evidence and reasoning that avoids our
| unbounded ability to fool ourselves. I.e. repeatable
| experiments by others, tested model predictions,
| mathematical and statistical checks, etc.
|
| That is all science and math are. An accumulation of
| tools and systems that improve the reliability of our
| thinking. They increasingly help us mitigate our
| exceptional talent for fooling ourselves.
|
| If we find another way to "know", it will get included
| into science too.
|
| -------------
|
| I'm sorry to be such a party pooper, but when religious
| or mystical people make epistemically unsound claims, the
| knives almost always come out for them, a little in the
| opposite direction shouldn't hurt too much. And besides:
| "science" _claims to_ welcome criticism, much like
| religious people claim to follow their scriptures. But
| then, who doesn 't like to have their cake and eat it
| too?
| Nevermark wrote:
| While I get your general critique I am not quite clear if
| you are critiquing me, including me with the science
| inspired confabulators.
|
| Just in case you were including me in that:
|
| For the record, the many worlds interpretation just
| sticks with the field equations of quantum mechanics
| (extremely well tested).
|
| It doesn't invent the quantum collapse, which actually
| isn't necessary to interpret them and which raises many
| questions that have never been well answered. I.e. when
| does collapse occur, how is information conserved if
| collapse keeps injecting information into all quantum
| systems, in situations with time reversal (different
| orders of events for different viewers in relativistic
| scenarios) how is information being destroyed. On and on.
| Collapse is both an unnecessary and problematic
| interpretation in an attempt to avoid a continuation of
| superpositions.
|
| What we see as collapse is just the experience of being
| included in the field equations as the quantum systems
| information becomes too complex (via thermodynamics,
| information escaping the experiment) for superposition to
| be detected anymore at a practical level.
|
| But as we learn to control larger and larger systems, we
| do indeed find superposition isn't bound by mass or
| system size. In fact, all of quantum computing depends on
| it not being bounded. It is just a challenge to keep
| information in isolation, I.e. from spreading in a way
| that is unrecoverable.
|
| Just as eventually we will be able to "simulate"
| intelligence in a quantum computer, we are already
| intelligence in a quantum system. We just can't control
| the quantum information in us so we lose any systematic
| relation/observability to the superpositions of our
| particles.
|
| Chemistry throughout our body operates consistently with
| the quantum behavior of all other chemistry. Our
| particles are no different from any other particles.
| mistermann wrote:
| I think it's interesting (though not surprising) that
| your long response avoided every single piece of your
| text that I quoted, as well as my question and other text
| (ie: the unknowable) of my critique.
| nonethewiser wrote:
| How does this comment relate to the comment it's replying
| to?
| zoeysmithe wrote:
| We're probably not getting to space without AGI or at least
| some level of sophisticated AI. At a certain point our
| biological bodies are just wed to the Earth and its ecosystem,
| as we are animals that are products of the Earth.
|
| If "we" ever get out there, some form of mechanical AI will.
| And we will never know it because once we send those ships off,
| we'll be long gone before the return signal gets to us from
| some far of locale. Imagine a voyager who can self-repair, mine
| asteroids, print circuits, etc. Now imagine giving it a 1
| million year mission. Maybe by then we'll all have given up on
| biology and we'd be the "robots" on that ship.
|
| Sometimes the universe makes beings like us, but not often, and
| probably makes all manner of interesting beings that will most
| likely be forever out of reach, and us out of their reach.
| Kudos to some life on a faraway planet, I wish we could meet.
|
| Also its fun to think of the universe as a system. Here's this
| incomprehensibly large thing constantly in motion, constantly
| having stars die out and explode, and new ones born, etc all
| the time but to us at incredible slow speeds, everywhere, yet
| at incredible distances from each other. Its like this bellows
| that keeps a fire lit, over and over, non-stop. But not quite
| non-stop because this great furnace too will (probably) have a
| proper death. This universe life cycle chart is both a feat of
| science and an incredible work of a permanent and grim
| mortality of all things.
|
| https://en.wikipedia.org/wiki/Graphical_timeline_from_Big_Ba...
| webwielder2 wrote:
| The vastness of the cosmos is kind of upsetting in an odd way.
| lostemptations5 wrote:
| Honestly, I'm happy to be alive to see these kinds of images! I
| wish my dad was still around he'd be fascinated.
| divbzero wrote:
| For a sense of scale, the Horsehead Nebula has a diameter of 7
| light years which is greater than the distance of 4 light years
| from us to Proxima Centauri.
| Koshkin wrote:
| From Wikipedia: _Most nebulae are of vast size; some are
| hundreds of light-years in diameter._
| golergka wrote:
| There's a lot of beautiful photos of distant nebulas and galaxies
| -- but if I understand correctly, astronomers actually construct
| 3d data. Is there a place where I can view these 3d models of
| different space objects?
| martijn_himself wrote:
| I always find it fascinating that what you are seeing is a 1500
| year old `close-up' of the nebula as that is how long
| (approximately) it took for the photons to get here.
| todotask wrote:
| We live in an exciting time where technology has evolved beyond
| imagination, yet the universe hasn't changed much in that short
| time span.
| madradavid wrote:
| Total noob question here and I apologize in advance. Are these
| the "actual" pictures or are they "touched up" by an artist ? If
| they the real pictures then this is truly impressive ...
| fooker wrote:
| It's the intensity of infrared(-ish) light hitting multiple
| sensors with different wavelength filters.
|
| If you were to look at it in person it would be a fairly smooth
| white patch. The colors are artificially assigned, but not by
| an artist. You pick a specific color for each wavelength. The
| Hubble palette is spelled out here:
| https://www.astronomymark.com/hubble_palette.htm
| whatshisface wrote:
| They're "touched up" in a scientific way to remove flaws in the
| telescope (light leaking in from the sides, some distracting
| aspects of the diffraction patterns that from around stars).
| The colors come from combining several black-and-white images,
| taken at different frequencies. You can explore the
| subjectivity of infrared images by opening them in GIMP and
| playing with the hue slider.
| seanw444 wrote:
| Well since these images are taken in a different part of the EM
| spectrum than visible light, the colors are false. But the
| images aren't touched up in the sense that shapes and sizes are
| altered.
| npteljes wrote:
| In case of most space photos, they are not what you would see
| with your eyes. Usually they capture data differently that how
| an eye would, and then visualize that. They sometimes strive
| for getting close to naked-eye perception, but usually it's not
| a goal.
|
| On this Wiki page you can see multiple such images, and the
| process described:
|
| https://en.wikipedia.org/wiki/False_color#False_color
| layer8 wrote:
| I wonder what the red and blue stripe artifacts are in the lens
| flares.
| zidel wrote:
| The 6+2 spikes around the bright stars is a diffraction pattern
| created by the edges of the hexagonal mirror segments (the six
| large spikes) and the three struts that hold the secondary
| mirror (also six spikes, but four overlap with the mirror
| spikes).
|
| https://smd-cms.nasa.gov/wp-content/uploads/2023/07/webb-dif...
| layer8 wrote:
| I'm aware of that. I was talking about the repeating pattern
| of blue and red stripes _within_ the spikes.
| dheera wrote:
| For a size comparison, here's a stacked, partially star-tracked
| image I took fully shot at 85mm on a full frame camera to show
| the perspective. The vertical 3 bright stars to the center/left
| are the belt of Orion.
|
| The small black notch in the red nebula to the bottom right of
| the belt is the horse head.
|
| https://www.instagram.com/p/CZp_R1npsT-/?img_index=1
| spxneo wrote:
| Absolutely crazy. when it zoomed out there were still whole bunch
| of galaxies
|
| how huge is the universe? its like asking ants how big the earth
| is.
| hughes wrote:
| I wonder how dynamic this place is. I know it's light years
| across, but is there any chance to see movement within the
| smallest structures if we were to revisit the same image on a
| ~yearly timescale?
| napolux wrote:
| The Crab Nebula changed over time, but it's of course a
| different kind of "nebula"
| https://esahubble.org/images/opo9622b/
|
| Maybe the horsehead nebula is different from 1 million years
| ago.
| mkl wrote:
| From the article: "The gas clouds surrounding the Horsehead
| have already dissipated, but the jutting pillar is made of
| thick clumps of material that is harder to erode. Astronomers
| estimate that the Horsehead has about five million years left
| before it too disintegrates."
| magnat wrote:
| JWST optics makes quite unique diffraction spikes. Not only that
| there are eight of them, but on full resolution images [1] they
| have distinct pattern, as if made from separate dashed lines.
|
| Are colors of those tiny lines (mostly red here - although this
| is false-color image) also diffraction artifacts, or do they
| correspond to actual spectrum of the stars causing them?
|
| [1]
| https://www.esa.int/var/esa/storage/images/esa_multimedia/im...
| PeterCorless wrote:
| That's how you can immediately tell a JWST image from Hubble;
| hubble has 4-spike patterns.
| relaxing wrote:
| The color gradation is due to phasing effects from the
| different wavelengths of light being combined, and the
| checkerboard effect is an artifact of the segmented mirrors.
|
| JWST has separate modes for spectroscopy. They're pretty cool!
| danielovichdk wrote:
| When I look at these images I instantly and fully understand why
| we are interested in the universe.
|
| It is such an incredibly thing. Absolutely astonishing.
| brcmthrowaway wrote:
| For this to exist and me shunting JavaScript around from place
| to place.. whats the point?
| bschmidt1 wrote:
| A million years from now our descendants will speak JSON.
| Your GitHub profile will be one of many temples and ancient
| sites - an Angkor Wat, a Gobekli Tepe.
|
| People of the future will ask: "{ "question": "What is this
| .gitkeep file?" }"
|
| And the sages will answer: "{ "answer": "It is a tomb or
| religious site." }"
| jodrellblank wrote:
| The point is that you get to buy dinner tomorrow.
| twism wrote:
| On the other planet they think it's a bear foot
| jcims wrote:
| I like the little happy sunrise galaxy looking thing that's at
| the top right corner of the bottom left square of the if you cut
| it into a 3x3 grid.
| jmyeet wrote:
| So the irony of these large cosmic structures is that if you were
| within them or in there proximity you wouldn't know. I mean you
| could see if you were in a nebula by the dust and gas you could
| detect in most or all directions. But you probably couldn't tell
| how that would look from 10,000 light years away.
|
| But there's a distance where such structures would probably fill
| the night sky because you were close but not too close. Some of
| these structures aren't necessarily visible to the naked eye,
| even if close, but some are. I wonder what that would do if you
| were on a planet where the horsehead nebula (or something
| similar) filled the sky and its brightness rivalled the Moon.
| holtkam2 wrote:
| Anyone else get the strangest sinking feeling in the final
| seconds when it's almost fully zoomed in and you come to the
| realization that the hundreds of specs in the distance are
| GALAXIES?
| bjelkeman-again wrote:
| Yes I did too. < Insert HHGTTG quote about how big space is > >
| it is kind of mind bending when I try to think about it.
| cconstantine wrote:
| Absolutely incredible.
|
| For a little bit of context for how impressive this is, here's my
| take on it with a consumer grade 8" Newtonian telescope from my
| backyard: https://www.astrobin.com/full/w4tjwt/0/
| peeters wrote:
| I mean I don't know if I'm more impressed by their level of
| detail from a $10 billion telescope or your level of detail
| from a consumer-grade telescope!
| cconstantine wrote:
| Thanks, but it if you look closely you'll see that the Webb
| image has almost an image worth of detail within each pixel
| of my image.
| xcv123 wrote:
| The James Webb image shows a level of detail we have never
| seen before. Hundreds of galaxies in the background that are
| invisible on the consumer grade telescope.
|
| Here's the full resolution image:
|
| https://www.esa.int/var/esa/storage/images/esa_multimedia/im.
| ..
| stoobs wrote:
| I'm quietly chomping at the bit for a Webb full deepfield
| survey rather than the hint of it we saw in 2022...
| peeters wrote:
| If this post is to be believed, a full deepfield survey
| would take four thousand to fourty thousand years. https:
| //www.reddit.com/r/jameswebb/comments/wrwsfc/how_long_...
| peeters wrote:
| Oh, don't get me wrong, I am absolutely astounded by the
| JWST's level of detail and am in awe of the pictures it
| takes. And they are obviously far more detailed than the
| OP's. I also think it was a worthy expense. I was just
| noting that my awe of both is comparable when you normalize
| for cost!
| notdang wrote:
| Once in a while, I have the impulse to buy the equipment to
| make these kinds of photos, then I check the price (at least
| 4k USD), realize I am not from US and cool down tell next
| time.
|
| It's consumer level, but not cheap at all.
| spenczar5 wrote:
| Its all relative, right? The cost is about a millionth of
| the JWST image. A millionth!
| estebank wrote:
| At that price difference it's silly _to not_ buy the
| gear! Right? Right?
| rkuester wrote:
| Your picture is itself quite impressive. Do you mind sharing
| more about the equipment and process it takes to capture
| something like that?
|
| Edit: Oh, you can click through the image and see technical
| details. Very cool.
| seabass wrote:
| You already noticed the technical card [1], but I can
| describe some of the details that go into this for those
| unfamiliar with the items on it.
|
| 1. The scope they used is roughly equivalent to shooting with
| an 800mm telephoto lens. But the fact that it's 8" wide means
| it can let in a lot of light.
|
| 2. The camera [2] is a cooled monochrome camera. Sensor heat
| is a major source of noise, so the idea is to cool the sensor
| to -10deg (C) to reduce that noise. Shooting in mono allows
| you shoot each color channel separately, with filters that
| correspond to the precise wavelengths of light that are
| dominant in the object you're shooting and ideally minimize
| wavelengths present in light pollution or the moon.
| Monochrome also allows you to make use of the full sensor
| rather than splitting the light up between each channel.
| These cameras also have other favorable low-light noise
| properties, like large pixels and deep wells.
|
| 3. The mount is an EQ6-R pro (same mount I use!) and this is
| effectively a tripod that rotates counter to the Earth's
| spin. Without this, stars would look like curved streaks
| across the image. Combined with other aspects of the setup,
| the mount can also point the camera to a specific spot in the
| sky and keep the object in frame very precisely.
|
| 4. The set of filters they used are interesting! Typically,
| people shoot with RGB (for things like galaxies that use the
| full spectrum of visible light) or HSO (very narrow slices of
| the red, yellow, and blue parts of the visible spectrum,
| better for nebulas composed of gas emitting and reflecting
| light at specific wavelengths). The image was shot with a
| combination: a 3nm H-Alpha filter captures that red dusty
| nebulosity in the image and, for a target like the horsehead
| nebula, has a really high signal-to-noise ratio. The RGB
| filters were presumably for the star colors and to
| incorporate the blue from Alnitak into the image. The
| processing here was really tasteful in my opinion. It says
| this was shot from a Bortle-7 location, so that ultra narrow
| 3nm filter is cutting out a significant amount of light
| pollution. These are impressive results for such a bright
| location.
|
| 5. They most likely used a secondary camera whose sole
| purpose is to guide the mount and keep it pointed at the
| target object. The basic idea is try to put the center of
| some small star into some pixel. If during a frame that star
| moves a pixel to the right, it'll send an instruction to the
| mount to compensate and put it back to its original pixel.
| The guide camera isn't on the technical card, but they're
| using PHD2 software for guiding which basically necessitates
| that. The guide camera could have its own scope, or be
| integrated into the main scope by stealing a little bit of
| the light using a prism.
|
| 6. Lastly, it looks like most of the editing was done using
| Pixinsight. This allows each filter to be assigned to various
| color channels, alignment and averaging of the 93 exposures
| shot over 10 hours across 3 nights, subtraction of the sensor
| noise pattern using dark frames, removal of
| dust/scratches/imperfections from flat frames, and whatever
| other edits to reduce gradients/noise and color calibration
| that went into creating the final image.
|
| [1] https://www.astrobin.com/w4tjwt/0/
|
| [2] https://astronomy-imaging-camera.com/product/asi294mm-
| pro/
| gregorymichael wrote:
| One of my favorite comments ever on HN. I'm big into
| photography and yet learned something on nearly every
| bullet. Thank you!
| cconstantine wrote:
| Well, if you think photography is too easy you could try
| taking up astrophotograhy :)
| alistairSH wrote:
| The exact opposite for me! I have a hard enough time
| getting composition and exposure correct shooting stuff
| here on Earth!
| cconstantine wrote:
| Thanks! I hadn't gotten to writing this out, but you've
| pretty much nailed it.
|
| > They most likely used a secondary camera whose sole
| purpose is to guide the mount and keep it pointed at the
| target object.
|
| I did use a guide camera with an off-axis guider, I'm not
| sure why it wasn't in the equipment list. I've added it.
|
| > The RGB filters were presumably for the star colors and
| to incorporate the blue from Alnitak into the image.
|
| This is primarily an RGB image, so the RGB filters were
| used for more than the star colors. This is a proper true
| color image. I could get away with doing that from my
| location because this target is so bright. The HA filter
| was used as a luminance/detail layer. That gave me a bunch
| of detail that my local light pollution would hide, and let
| me pick up on that really wispy stuff in the upper right :)
|
| > The processing here was really tasteful in my opinion.
|
| Awe shucks, thanks :blush:
| seabass wrote:
| Ah, of course it's HaRGB. Really cool. I'm curious, you
| de-star the color layers or leave them as is when
| combining channels? When I've tried HaRGB, the Ha layer
| has the best/smallest stars which means that the RGB
| color layers end up leaving rings of color on the
| background around each star.
| cconstantine wrote:
| I don't remember exactly what I did, but I do remember
| running into that kind of problem. I probably used
| starnet2 to remove stars before doing much processing,
| and recombining stars towards the end.
| wferrell wrote:
| Thanks for detailing this. Learned a lot.
| darkwater wrote:
| Now I need to know the ballpark cost of this whole setup,
| so it will block me from trying to get into yet another
| very costly hobby.
|
| EDIT: oh, just saw it
| https://news.ycombinator.com/item?id=40206558
| VikingCoder wrote:
| "Do you mind sharing more about the equipment and process"
|
| I'm sorry, but this is making me laugh so hard. I don't know
| a lot about astrophotography, but one thing I've experienced
| so far is that astrophotographers love to talk about their
| equipment and process.
|
| It's like asking a grandparent, "Oh, do you have pictures of
| your grandkids?" It kind of makes their day. :)
| cconstantine wrote:
| Haha, yeah. I could go on for hours. I've had to learn that
| most people really don't want a lecture series on the finer
| points of astrophotography. Seabass's comment was pretty
| much perfect; a bit of detail, but not so much to get lost
| in the detail.
|
| I tried to write a quick comment on my process a couple of
| times before they posted, and each time I had _way_ too
| many words on a small detail.
| mrexroad wrote:
| Nonsense! Just one more story, please?
|
| (Thanks for sharing!)
| cconstantine wrote:
| How about a talk by an expert on the topic of noise in an
| image: https://www.youtube.com/watch?v=3RH93UvP358
| bschmidt1 wrote:
| Amazing shot! Lots of good stuff, really liked this full moon
| shot https://www.astrobin.com/w0lzn5/B/ - the color!
| Vox_Leone wrote:
| Yours is a superb image, too. Very impressive indeed. Kudos!
| aronhegedus wrote:
| That's super cool!!! Looks like quite a niche/technical hobby
| with amazing output. Do you mind sharing how much equipment
| costs to get similar results?
| cconstantine wrote:
| It's a wonderful niche/technical hobby, but it's not cheap.
| You could even say it's "pay to win". I didn't buy all of my
| stuff at once, and I had some mistakes, but I'd guess I use
| on the order of $10k in equipment.
| alistairSH wrote:
| Just to follow on, you can gets started with quite a bit
| less. My dad took a stab at some basic shots with his
| prosumer Nikon and a basic tracking tripod.
|
| That's still $1000 body, $1000 glass, $500 tripod, give or
| take. So far from cheap if you're starting from scratch.
| But if you already have a body and some glass, it's not a
| stretch. Or, if you're ok with hunting for used gear, the
| body and glass can be ~half off new retail.
| NikolaNovak wrote:
| I'm assuming that'd be a non-moving/automated tripod?
|
| I have a d850 full-frame DSLR and either a 200mm 2.8 or
| 500mm 5.6, with some decent tripods; but earth's rotation
| tends to get me pretty quickly with any long-exposure
| photos :(
| alistairSH wrote:
| I think it's rotating, but doesn't have a secondary
| camera as described above. Maybe he spent more than $500,
| but I tend to doubt it, but I'm also not sure of the
| specifics beyond he's using a crop-frame Nikon DSLR with
| a lens he already had for birding (I think).
| cconstantine wrote:
| I've seen some pretty impressive stuff done with a
| relatively cheap / simple DSLR setup.
|
| The basics of astrophotography aren't that expensive, but
| it gets exponentially more expensive to meaningfully
| "zoom in". Because DSLRs with typical lenses are pretty
| zoomed out you can get away with much cheaper gear. You
| might look into getting a "star tracker". It's like a
| telescope mount for a camera; it'll keep the still
| relative to the stars but because they don't need to be
| as accurate they're far cheaper to make. They'll probably
| work just fine for your 200mm 2.8 lens for a fraction of
| the cost of a mount.
| supernovae wrote:
| Here is my Esprit 120mm widefield version
| https://www.astrobin.com/full/r97r5j/0/
| cconstantine wrote:
| Oh nice! Except for Alnitak (I love me some spikes), I like
| yours more.
| dudeinjapan wrote:
| TBH I like your shot more than JWST. You can at least see the
| whole horsehead. NASA should check their zoom setting.
| xcv123 wrote:
| Yep lets build a $10B space telescope to zoom out and use
| 0.001% of its resolution, matching a backyard telescope.
| dudeinjapan wrote:
| What good is a telephoto lens if you're just gonna zoom in
| on the very top of people's heads? It won't make for very
| good memories.
| noneeeed wrote:
| That's a really lovely shot.
| bbor wrote:
| This site uses WAY too much SPA crap, and the actual photo itself
| seems to be a broken link on my phone (that takes me to a weird
| squasi-progressive homepage without changing URL?).
|
| For anyone having similar problems, I recommend the source linked
| at the bottom of this blog post:
| https://esawebb.org/news/weic2411/
| bookofjoe wrote:
| I highly recommend "Deep Sky."
|
| https://en.m.wikipedia.org/wiki/Deep_Sky
|
| From the Wikipedia entry:
|
| >Deep Sky is narrated by Michelle Williams telling the story
| about the production of the James Webb Space Telescope and its
| impact on the technological improvements it made upon the Hubble
| Space Telescope.[6]
|
| https://www.imdb.com/title/tt28370567/
|
| https://youtu.be/5Mt_alPEyzI?si=36j5gKKrYUrOBI5w
|
| I was fortunate to watch it on Vision Pro in IMAX and it was
| spectacular.
|
| On the giant screen the Horsehead Nebula was mindblowing.
| dextrous wrote:
| I am reminded of David's song in Psalm 19 ... It's amazing to me
| how in the thousands of years since he wrote these words, we've
| still only scratched the surface of observing the beauty and
| depth of creation.
|
| The heavens declare the glory of God; the skies proclaim the work
| of his hands. Day after day they pour forth speech; night after
| night they reveal knowledge. They have no speech, they use no
| words; no sound is heard from them. Yet their voice goes out into
| all the earth, their words to the ends of the world.
| adamtaylor_13 wrote:
| Beautiful catch! I'm always amazed by the Bible's timelessness.
| Even when I know to expect it, it still impresses me.
| TerryHasRisen wrote:
| Crazy!
| mensetmanusman wrote:
| We are living inside of an infinite fractal. Who would have
| thought.
| mehdix wrote:
| If you haven't watched the short clip on the article, do it right
| now!
| endriju wrote:
| Is it roughly correct to think the speed of the camera in the ESA
| video would be 683,280,000 times the speed of light? Considering
| the zoom in took ~1 minute, and that's the number of minutes in
| 1300 years (the distance to Horsehead Nebula).
| EcommerceFlow wrote:
| I was watching David Kipping on Lex, and he mentioned some absurd
| number of requests to Hubble and Webb get denied (like 90%+).
| With Starship advancing at such a rapid pace, and with their
| launch size capabilities, I really hope cheaper "single purpose"
| telescopes start getting produced and launched. Could be a cool
| business opportunity for some obscure engineering company.
| sktrdie wrote:
| What do you all think all this comes from? To me personally it
| always baffles me with wonder. I think of the analogy of a mouse
| living in a cage. Do they actually even realize they are inside a
| cage? Inside a world constructed by some other being?
|
| What baffles me is that the explanation of reality is too complex
| for our brains to grasp. Same as to how the mouse will never be
| able to understand they live in a cage (or even the concept of a
| cage?) no matter the knowledge we throw at them.
|
| Such an incredible concept.
| nonethewiser wrote:
| It reminds me there is still so much to explore, although the
| threshold for exploring is so high.
|
| For context, I mean in comparison to earth. Consider that only
| 500+ years ago civilizations were discovering new land masses
| with unique flora and fauna. Discoveries that fundamentally
| changed the entire world as they knew out. Those sorts of
| discoveries are gone and that's rather depressing.
|
| But that is virtually nothing compared to the wonders out there
| in space. Unfortunately much of it is destined to be barren,
| unlike earth, and travel is kind of an unsolvable problem at
| the moment and perhaps forever. But the potential is
| unfathomable.
| rlhf wrote:
| Ultimately, the vision of beauty in the universe is as vast and
| diverse as the universe itself, thx for sharing.
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