[HN Gopher] James Webb Space Telescope finds 2 of the most dista...
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James Webb Space Telescope finds 2 of the most distant galaxies
ever seen
Author : Brajeshwar
Score : 91 points
Date : 2023-11-15 15:40 UTC (7 hours ago)
(HTM) web link (www.space.com)
(TXT) w3m dump (www.space.com)
| sounds wrote:
| Here's a slightly more in-depth link, still written by Penn State
| U's PR people but it links to the paper:
| https://science.psu.edu/news/WangLeja11-2023
| dylan604 wrote:
| I have a feeling that this headline will keep repeating itself as
| more imagery comes in and keeps getting analyzed. The first thing
| found from Webb that was further than Hubble gets "most distant
| ever seen", then the next thing from Webb that was further will
| get "most distant ever seen". We need to just have "most distant
| ever seen, yet" edit to them all
| Civitello wrote:
| Eventually, there will be a telescope to be the last to set the
| record for the most distant galaxy observed, because cosmic
| expansion will make it impossible to observe things so distant.
| I sometimes like to imagine what it will be like in the far
| future when you can only observe things a billion ly away, or a
| few million.
| mihaitodor wrote:
| I think it will take us a long time to map the entire
| "surface" of the visible sphere. Eventually, telescopes will
| be able to pick up some of the farthest galaxies, but there
| will always be one which might be a bit farther away, even if
| it won't be orders of magnitude farther.
| Ilverin wrote:
| The expansion of the universe is accelerating. At some
| point, the number of galaxies in the visible universe will
| stop growing and the light received from distant galaxies
| will grow more and more redshifted. However, it's possible
| that the redshifting will accelerate faster than our
| technological ability to detect more and more redshifted
| light.
| chongli wrote:
| I think we can fight back against this to some extent.
| The most distant galaxies are fading due to increasing
| redshift. If we build larger and larger radio telescopes
| then we should be able to continue seeing them at longer
| wavelengths. If in a billion years we manage to colonize
| a substantial chunk of our galaxy then maybe we could
| build a gigantic radio telescope out of many small
| collectors spread out over several light years.
| Ilverin wrote:
| You may be right, so I edited my comment.
| Larrikin wrote:
| Nothing in the universe can travel faster than the speed
| of light (we think), but the universe can expand faster
| than the speed of light. There are probably already
| objects we can't see and at some point in the far far
| future we will only be able to see objects in our own
| galaxy no matter how good our telescopes become.
| imoverclocked wrote:
| There may be other cool tricks that we haven't thought of
| too. No reason that we need to make things bigger and
| colonize the galaxy if we figure out something neat that
| is smaller instead! eg: Maybe we figure out that we can
| accelerate small telescopes to some significant fraction
| of the speed of light for an observation. Or perhaps we
| find some other neat physical phenomena to manipulate
| incoming light.
|
| The cool thing about scientific and engineering progress
| is that we can't know what we will discover and develop.
| 200 years ago, we started having electric lamps. In just
| 100 years time, we have gone from computers being fringe
| and folly to them being integrated into places they don't
| even need to be for sheer convenience. Assuming humanity
| makes it another 100 years and continues to advance
| technologically, things we only dream of today could
| easily be so common-place that people can't imagine
| living in the current dark-ages of technology.
|
| Also, 100 years is a cosmic blip! If we are thinking
| ahead to the point where we can't see things in the
| universe that we can see today, humanity itself will
| likely not be recognizable from our current vantage
| point... assuming it exists at all.
| dylan604 wrote:
| When I learned that the universe is not constantly
| expanding/compressing with multiple big bang restarts, I
| was kind of saddened at the fact it's not. Not sure why,
| but I liked that idea. Maybe the never endingness about
| it?? The coldness of everything eventually being so far
| apart and all stars will eventually burn out and just be
| a dark place is just meh for an ending. Much more anti-
| climatic that way
| echelon wrote:
| That we are the universe alive and experiencing itself is the
| most amazing thought in the world.
|
| By that same coin, the universe going dark is the most
| depressing and crushing.
|
| Let's hope our feeble understanding of the universe yields to
| a future full of more possibility than we can imagine today.
| irrational wrote:
| The reminds me of Asimov's short story "The Last Question"
|
| http://www.thelastquestion.net/
| TaylorAlexander wrote:
| It's like when apple announces "our greatest iPhone yet" as if
| they'd ever announce one which was "almost as good as last
| year's".
| baal80spam wrote:
| As a layman it always amazes me when reading such news that what
| we see now actually _happened there_ n years ago (in this case:
| 3.5 billions years ago). Not that it matters, but it is mind
| boggling nevertheless.
| lanna wrote:
| We are always seeing the past. If you are talking to someone a
| foot away from you, you are seeing how they were a nanosecond
| ago.
| seanw444 wrote:
| Yes, but that is beyond human perception. A nanosecond is
| pretty much now. Several billion years is a whole time
| machine.
| go_elmo wrote:
| But still - it unveils the "present" to just as well be an
| illusion of human categorical thinking, an abstract
| concept, not more. It is super useful to have none the
| less, just interesting to know its fragility.
| somenameforme wrote:
| Should we ultimately be able to develop relativistic
| rockets, and it seems there is no inherent reason why we
| shouldn't, then everything is just going to be so
| unbelievably weird. Traveling on a rocket to friendly
| distant planet, except the planet you land on may be
| millions of years in the future from when it was first
| settled. Or imagine living on said planets and
| occasionally seeing relics thousands, millions, or even
| further back in history approaching for landing.
|
| Time, life, death, technology, and everything will be
| just so unimaginably alien. It will be basically
| impossible to have a normal linear view of time when it's
| violated constantly, even though your body itself will
| yet still almost certainly be insistent on linear time -
| and steadily marching towards its expiration date. Even
| evolution itself will be weird. Humans over millions of
| years will probably scarcely resemble ourselves today,
| yet you'll regularly have 'old' species humans regularly
| reintegrating with 'new' ones?
|
| Such a bizarre reality we live in, unless perhaps somehow
| the views we have today end up being as quaint as those
| of times past.
| edgyquant wrote:
| Such a species won't be Homo sapiens anymore so this
| likely won't be weird to them.
| theideaofcoffee wrote:
| Maybe it will be a quaint, and ultimately solved, problem
| in that time but if the present is any indication, I
| can't imagine how old and new might interact.
|
| We already have enough problems with conflicts arising
| between people born in either side of an imaginary line.
| How will that work with humans born in different eons?
| denton-scratch wrote:
| > Should we ultimately be able to develop relativistic
| rockets
|
| Aren't all rockets relativistic? In the sense that
| "there's no inherent reason", I take it to mean "near to
| c", for some value of "near". that is, it's a "relative"
| term.
| flandish wrote:
| The only thing that travels faster than light is gossip.
| isaacg wrote:
| This article is about two galaxies which we are seeing as they
| appeared 300-400 million years after the big bang (over 13
| billion years ago).
|
| Those galaxies are magnified to the point where they are
| visible by another, much closer galaxy cluster, which is only
| 3.5 billion light years away.
| dfee wrote:
| Two amazing things:
|
| 1. these photos have been traveling for 13.5 billion years,
| just to meet their fate smashing into the JWST.
|
| 2. how many photons must have been emitted, that a sphere
| 13.5 billion light years in radius can still resolve the
| image.
| capitainenemo wrote:
| Well, due to the massive gravitational lensing from the
| intermediate galaxy a few billion years away, I guess it's
| not actually a perfect 131/2 billion light year sphere
| right... It's a fair chunk of the photons in the 10 billion
| light year sphere swept up and focused over a vast area and
| pointed in our direction.
|
| Still amazing to think about though.
| floxy wrote:
| The radius of the universe is closer to 46 billion light-
| years:
|
| https://en.wikipedia.org/wiki/Observable_universe
| qup wrote:
| The photons have emanated in a sphere from point of
| origin with a radius of 13.5 billion light years.
|
| The radius of the universe is irrelevant.
| capitainenemo wrote:
| Well, it's a good point no? If the universe is expanding
| as the photons propagate they are spread out into that
| larger sphere. So for the purposes of light gathering, a
| galaxy 13 billion years in the past has its photons
| spread over that much larger sphere into even greater
| invisibility. Although I guess in this case they were
| spread out into the larger sphere at the point of the
| expansion of the universe of a few billion years ago
| before being focused towards us - so. Some value
| significantly smaller than 46 but a lot larger than 10.
| Which makes it even more amazing to think about.
| oneshtein wrote:
| Do you have an evidence that space and time can be
| stretched at all? Can you stretch it a bit for me?
| irrational wrote:
| I just ate a bunch of food. I am now more massive. So I
| have stretched space around me a bit more than I did
| before I ate. You just need to make an instrument
| sensitive enough to detect it.
| function_seven wrote:
| I get the same amazement when I think about an ant I see on
| a tree five feet away. A photon was born somewhere in the
| middle of the Sun thousands (or more) years ago. It
| eventually made its way to the surface and--at extreme
| improbability--it traveled directly toward Earth. With more
| extreme improbability, it found itself on an intercept
| course with a tiny little ant on a tree.
|
| Layer on yet another high improbability, that photon-ant
| collision just so happened to send it directly toward _me_.
| Wait, not just me, but the tiny little pupil in one of my
| eyes!
|
| Tremendously large numbers and crazy minuscule fractions
| can be found in your backyard. Don't even need to leave the
| Solar System.
| matt-attack wrote:
| But if information can only travel at the speed of light
| shouldn't we consider the events being observed way out there
| as "now"? For all intents and purposes information couldn't
| have gotten here any sooner so it might as well be "now".
| edgyquant wrote:
| No that doesn't make sense
| just_boost_it wrote:
| When I saw this I thought it was a "water is wet" type story,
| because this telescope is supposed to see further than all the
| other ones we've made. The gravitational lensing aspect of it
| makes it cool though.
| denton-scratch wrote:
| So we can see stuff at z=13.
|
| What I can't get my head around is that the Milky Way either
| formed around the same time, 13 billion years ago, or it formed
| from stuff produced by galaxies that did. But we can't see the
| primordial Milky Way by pointing our telescopes at z=13. These
| old, faraway galaxies must have been formed just faraway enough
| from where our galaxy formed, that the expansion of spacetime has
| prevented their light from reaching us until "just now".
|
| So I wonder what distances apart the places where the primoridal
| Milky Way, and these two distant galaxies, must have been for the
| light to take so long to reach us. Like, the Universe was a lot
| smaller then; galaxies were much closer together.
|
| Galaxies at z=13 must have formed shortly after the Dark Age
| ended, and the Universe became transparent - like a few tens of
| millions of years - less than the time since the dinosaurs were
| knocked out (I'm assuming galaxies can't form in a plasma
| Universe, but maybe I'm wrong).
| irrational wrote:
| I've wondered the same thing. I'm hoping somebody knowledgeable
| replies.
| divbzero wrote:
| Your question in other words is: How far was the primordial
| Milky Way from these two galaxies 13 billion years ago?
|
| I don't have the answer on hand but it might be related to
| comoving vs. proper distances:
|
| https://en.wikipedia.org/wiki/Comoving_and_proper_distances
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