[HN Gopher] James Webb telescope's coldest instrument reaches op...
___________________________________________________________________
James Webb telescope's coldest instrument reaches operating
temperature
Author : wglb
Score : 368 points
Date : 2022-04-18 16:07 UTC (6 hours ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| belter wrote:
| "The Mid-Infrared Instrument for the James Webb Space Telescope"
|
| PDF: http://ircamera.as.arizona.edu/MIRI/paper1.pdf
| ResNet wrote:
| The fact that the telescope's cryocooler is acoustically
| symmetrical such that any vibrations made by each cylinder, and
| the actual flow of gas, is near-perfectly cancelled out is
| nothing short of amazing. [0]
|
| Real Engineering made a video that covered this and more, which
| is well worth a watch. [1]
|
| [0]
| https://webb.nasa.gov/content/about/innovations/cryocooler.h...
|
| [1] https://www.youtube.com/watch?v=aICaAEXDJQQ (The Insane
| Engineering of James Webb Telescope)
| AceJohnny2 wrote:
| Motorcycles have a similar constraint, so I'm a little blase on
| the technique.
| throwthere wrote:
| Kind of like a flat four or six engine versus inline/V6.
| red369 wrote:
| Flat fours and sixes definitely have a balance advantage over
| V6 engines, but I'm not sure there is much difference to a
| straight (in-line) four or six. They are also perfectly
| balanced until some higher order harmonic (something I can't
| really remember at the moment). The advantage of flat engines
| are that they are much shorter, but then they're heavier and
| more complicated because they have to have two heads. (Edited
| a typo in first sentence)
| t0mas88 wrote:
| The 6 in-line is the least vibrating one of the options,
| but the 4 is very close.
| red369 wrote:
| Were you including flat engines in that statement? Like,
| an online 6 is better balanced than a flat 6? If not, do
| you happen to know how a flat 6 compared with an inline 6
| for vibrations/balance? A quick search didn't find me
| anything. I know flat engines have to offset the
| cylinders a little.
| nickff wrote:
| Inline sixes are better-balanced than flat sixes.
| [deleted]
| [deleted]
| mywacaday wrote:
| This video https://youtu.be/5MxH1sfJLBQ was posted here
| https://news.ycombinator.com/item?id=30729109 about how the
| actuators work on the James Webb telescope. It's a great watch.
| dav_Oz wrote:
| Robert Warden (original author of the paper "Cryogenic nano-
| actuator" (2006)[0]) did the first prototyping with Lego
| Technic [1]. From Lego to the JWST, I mean damn, like
| childhood dreams come true (:
|
| [0]https://www.esmats.eu/amspapers/pastpapers/pdfs/2006/warde
| n....
|
| [1]https://m.youtube.com/watch?v=3WBrqUa_1yk
| nomel wrote:
| How is the position/correctness sensed? Do they calibrate
| based on the image of a known star (or something)?
| _fizz_buzz_ wrote:
| This is the kind of thing I would never come up with and if I
| did I would never think it would be possible to implement.
| There are some seriously ingenious people out there.
| sslayer wrote:
| Teams, seriously ingenious teams.
| pmcp wrote:
| effingwewt wrote:
| Diversity has nothing to do with anything here, the team
| could very well be entirely homogeneous.
|
| In this context, I'd say intelligence of said team
| matters, not their gender or race.
| birdyrooster wrote:
| That's the whole point of diversity being a blind spot,
| because intelligence isn't some integer value.
| interroboink wrote:
| I can't speak for the person you replied to, but my
| interpretation was "diversity of minds" (or "viewpoints",
| etc), not gender or race.
|
| Perhaps you'd agree that the diversity of opinions and
| points of view on a team is crucial, even if they're all
| X race Y gender.
| elzbardico wrote:
| Ideas never come from teams but from individuals. Teams
| implement, help to refine, other team members improve upon
| the idea with their own ideas. But the act of creation, is
| something done by an individual. Teams are not good at
| innovation, design by committee can only give us mediocrity
| atty wrote:
| I work in nuclear physics and no one of our experiments
| could be designed by a single person. They're far too
| large and complicated, and even relatively simple sub-
| parts are multi-year, multi-million dollar undertakings.
|
| Furthermore, even the ideas of "let's use X to measure Y"
| are VERY rarely completely new and unheard of ideas from
| a single individual. Far more common that those ideas
| come from long term collaboration/discussions between
| multiple field experts.
| FridgeSeal wrote:
| I think this is a bit reductive.
|
| I've definitely been a part of teams where we came up
| with ideas as a team. Individuals contributed, but the
| actual innovation came from the collective bouncing back-
| and-forth of ideas.
|
| We could get pedantic and say "it was still individuals
| coming up with the ideas" but that's needlessly splitting
| hairs and in my experience it's the team
| environment/cohesion that facilitates people coming up
| with said ideas.
| neb_b wrote:
| SmarterEveryDay also has a really interesting episode about the
| sun shield
|
| https://www.youtube.com/watch?v=Pu97IiO_yDI
| Diederich wrote:
| Yup, pretty much everything on this guy's channel is top
| drawer.
| bXVsbGVy wrote:
| The Launch Pad Astronomy is another great source for
| astronomic content [1]. I found pretty awesome the live show
| about JWST done with NASA scientists [2].
|
| [1] https://www.youtube.com/c/ChristianReady [2]
| https://www.youtube.com/watch?v=Xv7QiNjx_MY
| dralley wrote:
| He's pretty good but perhaps not very critical. I'm not sure
| that's necessary for the types of videos he produces but the
| ones about the Boeing 787 and especially Nikola seem a bit
| flowery given everything else we know about them.
| mardifoufs wrote:
| I mean a part from some teething flaws, the 787 is still an
| incredible plane. Brand new types are rarely introduced and
| they almost always have some issues early on.
| sgt101 wrote:
| I was certain this wouldn't work - it just looked so complex as
| to be a certain fail. But, those NASA and ESA dudes are smarter
| than me!
| tannhaeuser wrote:
| ESA's contribution, and that of Canada's agency I believe, is
| only very minor compared to the overall budget. Makes sense,
| and I guess it wasn't supposed to be this small, considering
| the budget was overrun ten-fold or so, and ESA having to
| explain desires for public money when it wasn't even "their"
| project.
|
| Anyway, JWST has been such an incredible success so far, I
| can't wait for the first science results.
| sph wrote:
| The JWST has been such a resounding success until now I just hope
| the first planetary system it sets its sights on we discover
| irrefutable proof of alien megastructures.
| BurningFrog wrote:
| Well, it's barely done anything but press releases yet. They
| always tend to look good.
|
| I'll celebrate when we see some important new data!
| WJW wrote:
| Hmmm. It would be cool to discover that, but also pretty
| worrying. Any civilization powerful enough to build a
| megastructure could wipe out humanity without any effort
| whatsoever, so we'd have to hope they are friendly enough not
| to do so.
| api wrote:
| If we found alien megastructures I think the most logical
| conclusion would be that we are subject to a kind of prime
| directive, effectively residing in a nature preserve, and
| that we are not intelligent enough to bother contacting
| (yet).
|
| On one hand it would suggest that our neighbors are either
| benevolent or at least indifferent, but on the other hand we
| might find it depressing to realize that we might be more or
| less insects at cosmic scale. It would have interesting
| existential implications.
|
| IMHO the Fermi paradox suggests that we are either early or
| late. This would be the "late" option.
|
| I have long doubted the dark forest hypothesis. Earth's
| atmospheric absorption spectra have been advertising the
| presence of a biosphere for almost a billion years at least.
| If there were any paranoid "reaper" intelligences around why
| would they even bother to wait for the evolution of something
| intelligent enough to leave the nest? Just whack candidate
| biospheres at first detection. It would even be a way to
| avoid some of the moral concerns that might arise from
| whacking fully sentient intelligences. Don't even let life
| get that far. If this were the nature of the universe I doubt
| we'd be here right now.
|
| Edit:
|
| I think the most disturbing thing to find would be apparently
| _dead_ alien megastructures. That suggests ugly things like
| periodic cosmic scale catastrophes like... I dunno... maybe
| the black hole at the center of the galaxy deciding every now
| and then to emit enough gamma rays to destroy anything more
| complex than microbes living deep underground. That would
| suck.
|
| Edit #2:
|
| Now that I think of it, this makes me remember yet another
| Fermi paradox idea I heard once. Maybe there is some periodic
| catastrophe like this and the reason we don't see aliens
| everywhere is that anywhere near a galaxy is actually a
| dangerous place. Once intelligences reach a certain level
| they figure this out and then pack up and head out into
| intergalactic space where they try to set up shop around
| rogue planets and stars and similar objects. Abandoned
| megastructures might be leftovers from the previous crop with
| the smart ones having left before the "event" got them. It
| would be an interesting thing to discover, because it would
| imply that there is a clock ticking.
|
| Fun sci-fi plot: there is such a clock, and we discover that
| the event is random. We could have anywhere from zero to a
| billion years left. Our first interstellar probes find two
| things: megastructures that are abandoned, and dead worlds
| and megastructures full of alien space mummies. The
| intentionally abandoned ones seem to be more or less launch
| support facilities built to harness and beam exawatts of
| power for as long as possible in the direction of
| intergalactic space, following what seems to be a trajectory
| toward a distant tiny extragalactic star cluster...
| marricks wrote:
| As soon as Europeans got big boats they ended up commiting
| genocide on everyone they encountered, so there's certainly
| reason to fear aliens behaving similarly.
|
| That said, it seems reasonable to expect any civilization
| that gets interplanetary technology would also develop ICBM's
| along the way if they wanted.
|
| Perhaps a certain amount of cooperation and kindness could be
| expected by anyone who makes it out into deep space. There's
| good reason to hope they'd be kinder than us I think.
| pixl97 wrote:
| You have it backwards. When you develop interplanetary
| travel, you by default have a weapon. Making any
| significant mass move through space fast can take a nuclear
| weapons worth of energy (honestly far more), if you
| lithobrake in the far side, that's going to be a massive
| explosion.
| jotm wrote:
| Not really, they enslaved anyone they could and stole their
| resources. Murder only happened when the locals were in the
| way.
| JohnBooty wrote:
| What comforts me:
|
| A reasonably strong belief that a species building
| megastructures will be fairly magnanimous. I believe that
| warlike, short-sighted species will destroy themselves and/or
| their planets before reaching the point where they are able
| to build such megastructures.
|
| What worries me:
|
| They may not _stay_ that way once reaching that level of
| achievement. Alternately, they may remain magnanimous amongst
| themselves and yet be deeply xenophobic when it comes to
| alien species such as humans.
|
| So far, the comforting thoughts outweigh the worrying ones in
| my mind.
| Tade0 wrote:
| My take is that everything about their lives would have to
| be focused and hyper-optimised towards the goal of
| producing such structures, so from a human perspective they
| would appear incredibly dull and featureless in every way.
| JohnBooty wrote:
| Hmmmm. That thought crossed my mind, too. Would they be
| like worker bees, building "beehives" large enough to be
| seen from hundreds of light years away?
|
| Exploring the stars would require a general-purpose
| intelligence that can span multiple eras: simple tool
| building, figuring out how to harness and store energy
| sources, science and math, etc.
|
| Is emotion required to achieve any of that, though?
| Probably, at least at first. I believe emotion is widely
| regarded as a valuable evolutionary aid, a crucial
| cognitive shortcut - at least at first, simply feeling
| that "predator is scary" and "sex is fun" is a hell of an
| evolutionary accelerant. You don't evolve to the point
| where you can _understand_ predators (something that
| takes a lot of biologically expensive brain matter)
| unless you have a gut-level _fear_ of them first
| (something that is biologically cheap).
|
| But at some point those emotions do more harm than good,
| I guess, if you're trying to build an interplanetary
| society. Our good old emotions are good for reproducing
| and being scared of predators, but aren't super helpful
| for managing Earth's resources across long time spans.
|
| Maybe the only way to make it past the great filters of
| nuclear war and environmental collapse is to discard
| those emotions somehow. Even if it's not the only way,
| seems like _a_ valid way.
| midrus wrote:
| Err... We're literally this close to wipe out ourselves.
|
| I'd still take the discovering of an advanced civilization
| any day.
| jandrese wrote:
| They only have to be friendly enough to not have to spend the
| massive amount of resources necessary to travel between solar
| systems simply to kill off beings you don't know for no good
| reason.
|
| People seriously underestimate how difficult it would be to
| travel between solar systems. The scales involved are so far
| beyond human experience that we can't properly visualize
| them. Short of discovering a practical FTL (which seems
| likely to be impossible thanks to the Fermi Paradox) it is
| unlikely that humans will ever visit a distant solar system.
| Georgelemental wrote:
| There are no fundamental physical barriers to sublight
| generation ships. It would be extremely difficult and
| expensive, and require lots of new technolgy--unlikely to
| happen without some supremely compelling motivation. But
| it's possible.
| ncmncm wrote:
| Truly, the only thing difficult is getting here in a
| hurry.
|
| Anybody not in a hurry would have little more difficulty
| than we did launching Voyager or New Horizons. They
| would, of course, need to build it such that it would
| operate for long enough to get here, which would be
| harder.
|
| Or, anyway, start operating again once it got near here.
| It ought not to be very difficult to preserve equipment
| cooled to 2.7 degrees above absolute zero, which is,
| notably, below the temperature where helium condenses.
| Maybe the boiling helium could be used to wake it up.
| addaon wrote:
| There's also a reasonable chance that the first immortal
| humans are alive today, depending on how optimistically
| you project maximum life expectancy curves with medical
| development. (There's also, of course, an extremely
| reasonable chance that they're not.)
|
| The dynamics of "generation ships" change drastically
| with changes in human lifetime, including both the
| dynamics on board such a ship, but also the motivation to
| pursue it.
| lazide wrote:
| Looking at how crazy many folks get being asked to stay
| at home, I don't give high odds to a generation ship of
| _awake_ humans ever making it intact anyway.
| omoikane wrote:
| They wouldn't simply kill us off, they would raid our
| resources first, if you believe Stephen Hawking.
|
| http://news.bbc.co.uk/2/hi/uk_news/8642558.stm
| ncmncm wrote:
| There is nothing we have that they haven't got, or could
| get overwhelmingly more easily than getting it from here.
| danlugo92 wrote:
| Our star is a pretty rare type, what if they want it
| whole D:.
| 317070 wrote:
| > It is unlikely that humans will ever visit a distant
| solar system
|
| Yes, but it is quite likely human technology will some day.
| worker_person wrote:
| But how likely any humans will be in a position to learn
| the results?
| pfraze wrote:
| Depends on your definition of human
| thedougd wrote:
| Trophy hunting. I've seen the movie.
| manquer wrote:
| > Short of discovering a practical FTL (which seems likely
| to be impossible thanks to the Fermi Paradox)
|
| You could colonize the galaxy in few hundred million years
| at most without FTL. Replicating machines which can build
| and launch many more of themselves after reaching each new
| resource rich system is all that is needed.
|
| Humanity may not reach other systems, but either
| descendants of humanity or human derived machines improved
| over many generations during transit by AI(doesn't have to
| be AGI) is likely to visit.
| AdamJacobMuller wrote:
| > for no good reason
|
| Why would it need to be a good reason? Especially why would
| it need to be a good reason, from our perspective?
|
| Hardly an original thought but it's entirely possible that
| an alien civilization pro-forma sends out an unmanned
| planet-killer-scale weapon at every alien civilization they
| detect, simply to avoid the possibility that we might grow
| up to be hostile to them, or even compete with them for
| resources.
|
| An unmanned bomb like that wouldn't take many resources and
| it's possible they would view us as primitively as we view
| stomping on an ant hill in africa.
|
| Now that's a depressing thought.
| supernovae wrote:
| Or, they send out probes for science, because only humans
| have the insatiable appetite for destroying each other.
| BitwiseFool wrote:
| >"because only humans have the insatiable appetite for
| destroying each other."
|
| Chimpanzees 'go to war', and so do some non-great ape
| species like ants and termites. Interestingly, some ant
| species conquer other colonies and essentially 'enslave'
| the defeated worker ants using pheromones. It stands to
| reason that belligerence would arise elsewhere in the
| universe because it has on Earth several times.
|
| https://en.wikipedia.org/wiki/Gombe_Chimpanzee_War
| ddingus wrote:
| Unless we are some true outliers, like way the hell off
| the farm, we are likely to share with them some basics in
| terms of continuing to exist amidst neighbors and
| ignorance.
| chmod775 wrote:
| > They only have to be friendly enough to not have to spend
| the massive amount of resources necessary to travel between
| solar systems [...]
|
| Not many resources really. They can simply use their
| abundance of energy to hurl, propel, or divert some rock at
| us at some non-negligible fraction of light speed, and we
| would be powerless to stop it. Likely we wouldn't even see
| it coming. Make it two or a dozen to be sure.
|
| It doesn't even take a very advanced civilization to pull
| off such a thing. Give it maybe a hundred years and
| humanity might be able to do it too.
|
| Since it is a rather easy to end a civilization in such a
| way and it is near impossible to defend against, you arrive
| at a very... interesting game-theoretic problem: Did they
| already send kinetic weapons our way? Should we destroy
| them before they decide to destroy us? If we're about to
| die anyways, does it even matter if we fire back?
|
| It's like the cold war except nobody is able to talk to
| another and you don't see the nukes coming.
| dorgo wrote:
| >to hurl, propel, or divert some rock at us at some non-
| negligible fraction of light speed, and we would be
| powerless to stop it.
|
| Wouldn't you need to solve the n-body problem to hit a
| planet (earth) from many light years away with a rock?
| And to do this without exact knowledge of planetary
| bodies in our star system. And even if you could, a stray
| hydrogen atom hitting your rock early on would make it
| miss its target by some light hours. So you better
| account for every speck of dust on the way and everything
| with gravitational pull on your rock. An all the quantum
| fluctuations..
|
| I would even wonder whether the space itself is fine
| grained enought to precisely target stuff light years
| away.
| gpm wrote:
| I don't think it's necessarily that massive an expenditure.
|
| Colonizing another solar system, that's massively
| expensive. Sending a single interstellar missile at the
| planet though... that could wipe us out... and definitely
| seems possible without a huge expenditure of resources (for
| a civilization with mega-structures).
|
| Missiles being much simpler because they don't have to
| support life, they don't have to slow down - and therefore
| don't need on board propulsion past what is needed for
| manoeuvring (assuming some sort of "push it with lasers"
| style of propulsion), and apart from systems needed for
| manoeuvring they can really just be a hunk of metal that
| you accelerate really fast.
| pantalaimon wrote:
| But what would be their motivation to do so?
|
| It would still be a huge effort - and for what? Why
| destroy a distant civilization?
| gpm wrote:
| For humans in a hypothetical advanced society the most
| likely reason would be preemptive self defence.
|
| I think it's a mistake to assume that aliens will be
| overly similar in their thought process.
| orlp wrote:
| Interstellar "rods from god":
| https://en.wikipedia.org/wiki/Kinetic_bombardment
|
| A civilization powerful enough to make mega-structures is
| almost certainly able of landing on one of its endemic
| large meteors, attach thrusters and over the course of
| decades accelerate it towards us in a collision path with
| the earth at a decent fraction of the speed of light.
|
| By the time we'd notice it would essentially be
| impossible to stop.
| est31 wrote:
| I wonder how you steer that thing. As in, earth is a
| pretty small target from a few light years away. In the
| case where you want to visit some planet peacefully, you
| spend the second half of the journey decelerating so you
| can do the needed corrections easily due to your lower
| speed, but if you are close to your target at a
| significant fraction of light speed, it's hard to change
| your course.
| mrlonglong wrote:
| I'd recommend reading the book
| https://en.m.wikipedia.org/wiki/The_Engines_of_God
| cercatrova wrote:
| I'd also recommend The Three Body Problem trilogy,
| specifically the second book, The Dark Forest.
| gigaflop wrote:
| I'm about halfway through, and can second the
| recommendation. I think I see a potential twist, but I
| want to see how it actually plays out in the end.
| pacoWebConsult wrote:
| I've watched Armageddon. All you need is a nuke and Bruce
| Willis.
| Tr3nton wrote:
| Please keep comments like this on reddit. Thank you
| sophacles wrote:
| Mr Willis is 67 years old. I suspect that any incoming
| attack asteroids are more than 13 years out (it just
| seems statistically improbable that one will show up
| sooner than that - I don't have any data on incoming
| bogies), and asking a >80 yo person to go take out
| asteroids seems like a plan destined to fail.
|
| Point being, we should hurry up and create a bunch of
| Bruce Willis clones before it's too late. The future of
| humanity depends on it!
| dylan604 wrote:
| No, you need Harry Stanton. Bruce is just an actor.
| dylan604 wrote:
| Doh! Harry Stamper
| richardw wrote:
| Why would you go through all that effort for a lower
| grade civ that had zero chance of attacking you and you
| couldn't get (and probably don't need) the resources.
|
| Next question: Are all distant civilisations friendly
| because there's no reason not to be?
| TheOtherHobbes wrote:
| Likely not.
|
| Convergent evolution. As soon as you get animals you get
| resource competition, violence, and a food chain with a
| predator at the top. In more sophisticated species you
| also get dominance/submission hierarchies.
|
| It's possible at some point a species might transcend
| that and become wholly benevolent. It's also possible
| that some species are cooperative colony organisms which
| somehow evolve intelligence, self-awareness, and
| technology.
|
| But at a guess it's more likely that most species remain
| aggressive and competitive for a very long time, and
| they'll only ignore humans if we aren't complex enough to
| be a threat - now or in the future - and have nothing
| worth stealing or harvesting.
| jotm wrote:
| Missile as in asteroid. Why bother with anything but the
| engines, big rocks are more than enough for interstellar
| warfare. Perhaps that's what got the dinosaurs and
| there's another one on its way right now :)
| SkyMarshal wrote:
| They could probably also cover such an asteroid in some
| sort of stealth coating relatively cheaply, so we
| wouldn't even detect it until a few hours before impact.
| kadoban wrote:
| They wouldn't even have to, really. We see almost nothing
| out there, coming towards us or not, and even if we saw
| it a year early, what could we do about it?
| gpm wrote:
| > even if we saw it a year early, what could we do about
| it?
|
| You could try sticking various forms of interceptors on
| it's path, at those speeds it's probably not maneuvering
| so relatively easy to intercept if you have warning.
|
| I'm not sure to what degree we could deflect it or
| mitigate the damage, but I wouldn't be surprised if it
| was a sizeable one. Any collision is going to convert a
| ton of energy from kinetic energy to thermal energy,
| which should in large part radiate away before impacting
| earth. We could also do various clever things like
| putting hydrogen targets in the way which would undergo
| fusion upon collision with an object moving at
| relativistic speeds.
| runarberg wrote:
| A sample size of 1 suggests this wouldn't happen.
|
| Humans are the most aggressive species we know of capable
| of mass destruction. We would (and do) certainly destroy
| other species to get some resources in order to enrich a
| small but highly privileged portion of our population.
| However--despite our aggression--we would not destroy an
| alien world at the mere sight of it without any prospects
| for profit.
|
| Our most destructive era was probably the era of nuclear
| missile testing. It certainly did an enormous needless
| destruction of non-human (and human) habitat. This era
| only lasted a couple of decades and ended with a
| comprehensive test ban in the 1990s. Despite our
| capabilities we never tested these weapons of horror in
| space or on alien planets, and we probably never will.
| formerly_proven wrote:
| > It certainly did an enormous needless destruction of
| non-human (and human) habitat. This era only lasted a
| couple of decades and ended with a comprehensive test ban
| in the 1990s.
|
| PTBT happened in the early 60s, so almost all surface
| tests were conducted within the first twenty years of
| developing nukes. I don't think making "craters" in
| desert mines really qualifies as enormous destruction of
| habitats.
| runarberg wrote:
| Yes the second and third decades of nuclear weapons
| testing were definitely more destructive then the
| following. The Partial Nuclear Test Ban Treaty of 1963
| definitely helped slowing down the destruction by a lot.
| However e.g. France--a non signatory--continued
| detonating their nuclear bombs above ground on and around
| their pacific island territories well into the 70s. The
| environmental damage (and damage to the nearby human
| communities) is still very much present today.
|
| But the fact that the PTBT was signed by most nuclear
| states which slowed down this pointless destruction--and
| later the CTBT, which almost stopped it in 1997--shows
| that even humans with our demonstrable aggressiveness do
| work to limit our destruction when said destruction
| doesn't contribute to the enrichment of a subset of other
| members of the species.
| krisoft wrote:
| > Despite our capabilities we never tested these weapons
| of horror in space
|
| I'm afraid that is not true.
|
| https://en.m.wikipedia.org/wiki/Starfish_Prime
|
| "The explosion took place at an altitude of 250 miles
| (400 km), above a point 19 miles (31 km) southwest of
| Johnston Atoll."
|
| That's roughly the same altitude the international space
| station flies at.
| formerly_proven wrote:
| And then there's "Project K" where the Soviets EMP'd
| their own population for science.
| krisoft wrote:
| Oh! Very interesting. I didn't know about that one. Thank
| you.
| runarberg wrote:
| Yes, you are right. I forgot about that one. Of course
| the Partial Nuclear Test Ban Treaty banned those in 1963.
| cercatrova wrote:
| Indeed, the dark forest hypothesis (from the book The Dark
| Forest, the second in The Three Body Problem trilogy) talks
| specifically about this:
|
| > _The universe is a dark forest. Every civilization is an
| armed hunter stalking through the trees like a ghost, gently
| pushing aside branches that block the path and trying to
| tread without sound. Even breathing is done with care. The
| hunter has to be careful, because everywhere in the forest
| are stealthy hunters like him. If he finds other life--
| another hunter, an angel or a demon, a delicate infant or a
| tottering old man, a fairy or a demigod--there's only one
| thing he can do: open fire and eliminate them._
|
| If we posit that beings must kill each other, then we must
| also kill others, lest they kill us first. It may not even be
| the case that anyone wants to kill another, but simply
| because the possibility is there, this then becomes a tragedy
| of the commons, a self-fulfilling prophecy.
|
| The rational course of action, then, is to hide as much as
| possible, and if you notice anyone, eliminate them before
| they do you.
| kortilla wrote:
| This assumes that aliens building megastructures have as
| simplistic thinking as us.
| WJW wrote:
| It might also be that they have more sophisticated
| thinking, that still leads to the same conclusions? I see
| no inherent reason why more sophisticated thinking would
| always be more peaceful.
| formerly_proven wrote:
| https://arxiv.org/pdf/1302.0606.pdf
| jdjdjdjdjsjs wrote:
| The good news is that the sum total of your existence is the
| preservation of energy, and you cannot be "wiped out". Time
| passes, things change, including your sense of self.
| AdamJacobMuller wrote:
| If my energy is sufficiently changed from it's present form
| such that I can no longer enjoy my morning coffee, it
| doesn't really matter to me.
| ndichbebe wrote:
| wetpaws wrote:
| There is nothing wrong in alien civilization wiping out
| humanity.
| SkyMarshal wrote:
| Any civilization that could build a megastructure, probably
| already built their own JWST hundreds or thousands of years
| ago, and by now has far more advanced technology for
| detecting other technological civilizations, and probably
| already knows about us.
| jandrese wrote:
| At the very least alien telescopes can detect the change in
| composition of our atmosphere as a result of
| industrialization. We could do this using today's
| technology, so for any civilization with the ability to
| actually travel between solar systems it is childs play and
| they would easily have continuous monitoring of all nearby
| solar systems looking for abrupt changes in the atmosphere.
| pantalaimon wrote:
| We would still need continuous monitoring of the planets
| for decades, right? Or can we already make that out in a
| single snapshot?
| jandrese wrote:
| A single snapshot tells a lot (NASA already does this),
| but continuous monitoring would be almost free at that
| point so you would have to assume it is happening as
| well.
| TaylorAlexander wrote:
| Unless they died out before we invented radio and all that
| exists now are their ancient structures!
| SkyMarshal wrote:
| Yes, they might have all gotten "great filtered" first.
|
| Wouldn't it be interesting if all the intelligent species
| in the galaxy got filtered, except humanity b/c we're
| relative latecomers to evolution and development.
|
| Assume on most or all other habitable planets in the
| galaxy, the first species to develop was intelligent and
| capable of technology. But, all hit the Great Filter at
| the roughly same time and got wiped out. There was no
| chance for any of them to learn from the mistakes of the
| others, because they all got wiped out before they were
| able to detect and observe each other.
|
| But on Earth, the dinosaurs came first, and roamed the
| planet for millions of years while all these other
| species were developing and then getting great filtered.
|
| Then the dinosaurs went extinct, and humanity eventually
| evolves into a technological civilization, and is able to
| detect, study, and learn from the ancient ruins of the
| other civilizations. We get curious about why they went
| extinct, and then discover evidence of the Great Filter
| from their ruins, and thus avoid it ourselves.
| ddingus wrote:
| Extending that a bit...
|
| We are among, or perhaps the first of a post filter
| generation. We do avoid the thing, as do others and
| eventually arrive at a mode of existence and thought
| making more possible, friends possible.
| radicaldreamer wrote:
| They probably wouldn't even care that we exist. It would be
| like going after some ants that are far away and not capable
| of bothering you.
| dahfizz wrote:
| Until they decide they want our water / oxygen / etc and
| they take it all without any thought given to the the
| impact on a few ants.
| ctoth wrote:
| This metaphor has always bugged me. If we noticed some ants
| somewhere that, over the last thousand years, got way
| better at building colonies I think we'd at least be
| interested, if not concerned. No matter how long we leave
| them, ants will not figure out how to build their own JWST.
|
| Human intelligence seems as though it is fundamentally
| different, in that we can preserve and build on previous
| knowledge. So I'm pretty sure that aliens, detecting
| intelligent life, wouldn't just be like "oh, just some
| ants." Or if they are, we better hope we don't find
| ourselves in their pantry.
| mr_mitm wrote:
| We also literally have scientists studying ants. We even
| put ants on the ISS. It's not like there is nothing to
| learn from ants.
| postalrat wrote:
| Maybe not now but in 100k years? Who knows.
| tayo42 wrote:
| They would have been there the whole time, they didn't just
| pop into existence because it got observed. I don't think you
| need to worry anymore then usual
| swarnie wrote:
| Does something exist if you can't/don't observe it?
| carlio wrote:
| If a tree falls in a forest and no one is around to hear
| it, does it make a sound?
| wglb wrote:
| Don't know, but I have always wondered if the other trees
| laugh at it.
| ddingus wrote:
| I love that. I feel a sense of perspective change that I
| like. Reminds me to remain vigilant about my sense of
| play. Losing it happens slow, and yes I have and have
| noticed.
|
| Little bits add up. I like this one.
|
| ( scroll right on by, as this is one of those things we
| might say for the benefit in saying it, not so much value
| otherwise)
| jandrese wrote:
| > If a tree falls in a forest and no one is around to
| hear it, does it make a sound?
|
| If you define sound as a wave of air (or any other
| medium) particles then yes.
|
| If you define sound as something a person had heard then
| no.
| simulate-me wrote:
| > I don't think you need to worry anymore then usual
|
| Or, you realize that your usual level or worry is totally
| inadequate and that you should have been worrying much more
| in the past.
| meetups323 wrote:
| Yes, because if you had been living a life full of worry
| you'd be much better prepared to take on the alien
| invasion.
| sgustard wrote:
| This is also why I don't go to the doctor.
| TedDoesntTalk wrote:
| Sticking your head in the sand doesn't make a problem go
| away. Face life with openness.
| Trasmatta wrote:
| Worrying is only useful inasmuch as it compels you to
| act. What actions could we have taken in the past to
| prevent a future alien threat? Besides never sending
| electromagnetic signals into space?
| ISL wrote:
| Schrodinger's civilization :).
| a_wild_dandan wrote:
| I don't follow. Are you saying that new information doesn't
| justify new reactions? Like if I get a cancer diagnosis, I
| shouldn't worry more, because the misbehaving cells were
| there the whole time?
| tayo42 wrote:
| I think going with this metaphor if you have cancer then
| it's like already being under attack by this
| civilization.
| throwawaycities wrote:
| > They would have been there the whole time, they didn't
| just pop into existence because it got observed.
|
| Unless they are quantum beings.
|
| But more seriously, at cosmic scales it is possible we
| observe something/some civilization in our present that
| actually no longer exists. There should be something like
| the Drake Equation to determine the likelihood of a
| civilization we observe actually currently existing based
| on the observed distance.
|
| To your point the oldest radio broadcasts are just over 100
| years old, since they travel at the speed of light they
| will need 100,000 years to travel the length of the Milky
| Way, so if a civilization as advanced as ours were on the
| other side of the galaxy in the future to receive them,
| what are the odds humans will still be around? Assuming we
| are around, then it would be about another 100,000 years
| for them to send a directed communication at the speed of
| light, so I think you are correct it's not worth the effort
| to worry.
| contravariant wrote:
| Anything more than a few dozen lightyears away could have
| conceivably detected us and taken action to erase the
| threat.
| pradn wrote:
| Going from "unknown if alien civs with megastructures" to
| "proof of alien civs with megastructures" is new
| information that would change the trajectory of humanity.
| jandrese wrote:
| How? Other than focusing our efforts at communication
| with alien species I don't think the day to day life of
| your average person would be at all different. They are
| basically a curiosity. Even if we did finally find some,
| they would likely be so far away that round trip
| communications would take decades or centuries.
| dylan604 wrote:
| Ever read/see any sci-fi at all? Lots of them have
| provided story lines of humantiy not handling this
| information well. From religious cults to doomsday
| preppers to all sorts of irrational behavior, the way
| humanity accepts we're not alone is not always thought to
| be positive.
| michaelwilson wrote:
| Heh. Read the news lately?
|
| . Religious Cults. If you look at the religiously
| inspired insanity in US Laws and Politics recently,
| coupled with what's going on in, say, Afganistan, I'd say
| "check".
|
| . Doomsday preppers. Check.
|
| . All sorts of irrational behaviors. Well, if you include
| enabling destructive climate change in the face of
| overwhelming evidence, I'd say Check.
|
| It's almost like we read all those stories and said "Hold
| my Beer".
| dylan604 wrote:
| Or those stories based their plots on these real life
| scenarios dialed to an 11
| TedDoesntTalk wrote:
| Sure there will be a few people acting irrationally; such
| people already exist and act irrationally.
|
| Most people will say "meh" unless it affects their daily
| lives.
| ngngngng wrote:
| Well, I just think they're neat
| mywittyname wrote:
| I suspect most people who'd find this information to be
| more than a novelty already genuinely believe in alien
| life anyway.
|
| What use to them is confirmation from an entity they
| don't even trust?
| pixl97 wrote:
| Well, for one all those religious people that believed
| they were the centre of the universe will be doing some
| random scrabbling to explain the change in the status
| quo.
| pc86 wrote:
| If the pandemic is any indication, the people for whom
| alien life doesn't fit into their world view will simply
| insist that it's been faked.
| jotm wrote:
| "Oh, of course there's life on other planets, God made
| them, too".
|
| Tbh, churches funding an interstellar mission (to convert
| the heathens) would be a mostly good thing
| lucb1e wrote:
| Until someone commandeers the Mormons' generation ship to
| push an asteroid into the sun
| politelemon wrote:
| The Three Body Problem series actually covers an aspect of
| the terrifying nature of discovering other civilizations.
| It's a nice read for the sake of the concepts and the thought
| exercise. https://www.goodreads.com/book/show/20518872-the-
| three-body-...
| Trasmatta wrote:
| Given that they would have had to begin their journey a long
| time ago, better to at least know they exist before they get
| here.
| ddingus wrote:
| They would have to care about us first.
|
| For all we know there is a space buoy of some kind out there
| some big units away...
|
| "Non Contact Status: Toxic
|
| Species shits where it eats, is actively killing one another,
| and has a basic nature of aggression and domination, and
| reproduce like weeds.
|
| Planned status reevaluation + 100k yearly time type units"
|
| Such a discovery could unify us in a way not possible right
| now.
|
| As far as we know there currently is no higher entity in
| play. The moment there is... hoo boy!
| sph wrote:
| Seeing them before they could see us would be ideal.
| [deleted]
| randomsilence wrote:
| Nature could act as a filter. If you reach industrial
| production and you destroy nature, your entire planet may
| die. So only civilizations that have some level of respect
| for life itself may pass the barrier where they can build
| megastructures and reach other planets.
| [deleted]
| polishdude20 wrote:
| It must be such a rush to know that your instruments which were
| tested only locally in various simulated environments work
| perfectly in the environment in real life.
|
| I had this sort of feeling when working on a model rocket with a
| complicated flight computer. I did months of simulations,
| testing, planning , rereading the code and getting it ready. Once
| I pressed the launch button, all that work culminated into it
| working or not working and trusting that those days and nights of
| testing were enough.
| Aperocky wrote:
| There's the other and more common strategy in terms of software
| development and that is deploying a large amount of iterations
| and/or products and fix what's broken.
|
| Elon Musk applied that successfully to rocketry.
|
| It must be nice to know if this one didn't work you're going to
| launch the next one in a few weeks...
| polishdude20 wrote:
| Oh for sure, if you've got the money to break things at the
| hobby level :)
| [deleted]
| punnerud wrote:
| "Another reason Webb's detectors need to be cold is to suppress
| something called dark current, or electric current created by the
| vibration of atoms in the detectors themselves."
|
| Can this be used for energy production?
| ars wrote:
| For energy production you need a hot source and a cold source.
|
| This dark current is no different. You'll need energy to create
| either the cold source or the hot source.
| seanw444 wrote:
| Heckin thermodynamics.
| m3kw9 wrote:
| I really hope the first pictures won't be a "better" pixelated
| dot that is better because this one is way further out in space
| and never seen.
| sbierwagen wrote:
| JWST vs Spitzer in near infrared is a striking difference:
| https://twitter.com/gbrammer/status/1504369779540480002
| floxy wrote:
| That's a cool photo. Is there a similar comparison of that
| photo from the JWST to one done in visible light?
| sbierwagen wrote:
| Not really. Ten minutes of googling didn't find anybody
| pointing a high resolution instrument at HD 84406, just sky
| surveys.
|
| From this comment
| https://news.ycombinator.com/item?id=30093849 here's one
| square degree (3600 square arcminutes) of sky around the
| star: https://bsrender.io/sample_renderings/hd84406-1deg-m1
| 8-ax100...
|
| If the published calibration image is a single NIRcam
| exposure, then it's a 2.2x2.2 arcminute square around the
| central star, or, at the scale of the Gaia photo, a 33x33
| pixel box. The Airy disk pretty much takes up the whole
| thing at that scale.
|
| You can also take a look via CDS portal:
| http://cdsportal.u-strasbg.fr/?target=HD%20%2084406 Various
| sky surveys also show little detail at 2.2 arcmin.
| jakear wrote:
| I think the real question is whether the images will
| generally look distinctly different from existing space
| telescope images. In the example you provide, the JWST image
| is only remarkable because the sampled area is too small for
| Spitzer to accurately resolve. If you were not comparing area
| to area but instead just trying to find an image that looked
| almost identical to JWST's, it would be much harder to spot
| the improvement.
|
| Think of looking at a mountain. It looks like a mountain.
| Then focus on a cliff of that mountain. It looks really quite
| similar to the mountain. Focus on a boulder on that cliff.
| Again, quite similar. A rock on that boulder. Similar. It's
| only when you reach the microscopic/atomic scale that the
| structure is revealed to be something totally different from
| what it was before and you learn it's not rocks all the way
| down. There's something _different_ there, but it requires
| spanning a very large number of magnitudes to arrive at it.
|
| Now, we've seen some _different_ things from existing
| telescopes. Galaxies, nebulas, etc. look absolutely nothing
| like stars as seen by the eye (a bit like how you 're sure to
| happen by plants and animals while zooming into that
| mountain). But as the resolution increases I am not sure that
| we've had that next leap. The Hubble deep field image for
| instance looks basically the same as the Hubble ultra deep
| field.
|
| In short, will JWST reveal new structures so distinct from
| anything we've seen before that upon looking at an image it's
| immediately obvious that such an image could only have come
| from JWST, or will the images look like the plethora of
| existing telescope images, just at a different scale? I
| certainly hope for the former but my intuition is leaning
| more towards the latter. I'd absolutely love to be proven
| wrong here.
| baggy_trough wrote:
| Better source: https://blogs.nasa.gov/webb/
| jylam wrote:
| I was so convinced, after all the delays, the cost overruns and
| the general bureaucracy surrounding the whole project, that it
| would fail miserably.
|
| I'm so happy it seems to go flawlessly since its (perfect)
| launch.
| Tozen wrote:
| Agreed. I was thinking this thing would be a bust or expecting
| some type of catastrophe, so nice to see none of that happened.
| This has undoubtedly exceeded the expectations of many.
| CogitoCogito wrote:
| This was an interesting article along those lines:
|
| https://arstechnica.com/science/2022/01/whats-left-for-the-w...
| gameswithgo wrote:
| The two most recent large US mars rovers, and James Webb all
| seemed way too complex to ever work. All 3 worked!
|
| Shows what I know.
| lisper wrote:
| It's not just you. I worked at JPL for twelve years and I
| expected it to fail too. I can't tell you how happy it makes
| me to be wrong about this.
| pkaye wrote:
| Unfortunately small problems can still happen. The recent
| Lucy mission to the Jupiter asteroid belt had a problem with
| one of the solar panels not properly unfolding. However they
| feel the remaining panel has sufficient power to complete the
| mission.
| jrootabega wrote:
| We're all still traumatized by the meters/feet problem. Oops,
| I mean the Newtons/pounds problem.
| ResNet wrote:
| Same here, the relief I felt when it completed the riskiest
| unfolding steps was huge. I'm so excited to see the results it
| provides.
| tomrod wrote:
| I hope to learn the stories of the people who made it work,
| despite the cost overruns and bureaucracy!
| digbybk wrote:
| The delays, the cost overruns and the general bureaucracy
| surrounding the whole project are likely the reasons why it
| _didn't_ fail miserably. It's definitely not a situation where
| you want to move fast and break things.
| formerly_proven wrote:
| Projects that push aside the envelope of what was previously
| possible and reach entirely new levels of performance tend to
| have not that predictable schedules and costs. I'm pretty
| sure the planners involved know that, but on the political
| level fixed ranges and estimates are required to get funding
| - so you get cost overruns and delays.
| perardi wrote:
| Every HN thread brings up the cost overruns, and I
| just...OK, smart guy, you come up with a reasonable
| estimate of shooting a telescope into a very distant orbit
| and then cooling it to 12 degrees above absolute zero.
| HPsquared wrote:
| Also, they probably wouldn't have gotten funding at the
| start if they said it'd take 25 years and 10 billion.
| Starting with a low-ball and gradually ramping up has a
| greater probability of (funding) success.
| lisper wrote:
| And the fact that everyone knows this leads to some
| interesting game theory.
| kortilla wrote:
| No, the bureaucracy is not why it didn't fail. Cost overruns
| and delays due to reworking stuff I can buy but I've seen
| tons of projects fail with plenty of bureaucracy (see the
| initial healthcare.gov launch).
| jollybean wrote:
| No, cost overruns are generally a sign of things going bad,
| not 'just more money for double checking'.
|
| The Gov. of Canada Payroll system is now up to $1B with no
| end in sight.
|
| --> Payroll. System. $1B.
|
| I'm stoked this worked though can't wait to see the photos.
| dwighttk wrote:
| Finally...
| colordrops wrote:
| Will the JWT be able to see the actual shape of stars and planets
| rather than just points of light?
| Jabbles wrote:
| No, it would need ~3 orders of magnitude better resolving power
| to do that, even for the closest star.
|
| Definition of parsec: https://en.wikipedia.org/wiki/Parsec
|
| Angular resolution of JWST:
| https://jwst.nasa.gov/content/about/faqs/faq.html#sharp
| colordrops wrote:
| Thanks
| pkaye wrote:
| The Roman telescope coming later this decade might do it. It
| will have an improved coronagraph that might help see
| exoplanets. They are using adaptive optics and special lenses
| in a coronagraph to better mask out the light form the star.
| But mostly likely that coronagraph on a proposed 15m LUVOIR
| telescope is where we start seeing things in detail.
|
| https://roman.gsfc.nasa.gov/exoplanets_direct_imaging.html
| floxy wrote:
| You may be interested in:
|
| Direct Multipixel Imaging and Spectroscopy of an Exoplanet with
| a Solar Gravity Lens Mission
|
| https://www.youtube.com/watch?v=NQFqDKRAROI
|
| https://arxiv.org/abs/1802.08421
| marina123456 wrote:
| Interesting!
| marina123456 wrote:
| Sorry for the excitment
| Joel1234 wrote:
| Dont be sorry
| lucb1e wrote:
| The list of cool programs approved is astounding:
| https://www.stsci.edu/jwst/science-execution/approved-progra...
|
| Small selection that jumped out at me:
|
| > Mineral Clouds in the Atmosphere of the Hot Jupiter
|
| > The JWST Protostellar Ice Legacy Survey
|
| > Analysis of Low-Albedo Asteroids
|
| > Composition of an Interstellar Object - Unique Insights into
| Protoplanetary Disk Midplane Chemistry
|
| > Mapping, Resolving and Penetrating into the Dusty Spiderweb
| Protocluster with Unique Pa-beta Imaging
|
| The list just goes on and on, and I also found that the site
| hosts similar stuff for the Hubble telescope and more. Just a few
| hours ago, the HST looked at
|
| > A wide, red-giant plus non-interacting black hole binary, or
| triple stellar system?
|
| https://www.stsci.edu/hst/phase2-public/16654.pro
|
| Instrument configuration, apertures, location to point it at of
| course, where in the orbit around earth it is at the time needs
| to be considered... this isn't as much point and shoot as one
| might think (I didn't consider this before). It also shows a
| warning message: "Electrons per pixel due to background (0.26) is
| less than the recommended threshold of 20 electrons". Since this
| was scheduled for only hours ago I guess the results won't be
| known for months, but even just what goes into the scheduling and
| configuration, there's so much info here.
|
| Is there a channel or website somewhere that keeps up with the
| results? The list is way too long to really go in-depth on all of
| them, but 2 minutes about what the objective was and what they
| found would be super interesting for many of them.
| adhesive_wombat wrote:
| God I wish there was a podcast about this kind of thing: just
| get stuck in deep to some kind of hyper-focused thing per week.
| Even if sometimes I don't fully understand every concept, I'd
| take that over having "atoms have a thing called a nucleus"
| being the general level of explanation or recycled press
| releases levels of content for the commute.
|
| Really winds me up about things like James May's programme
| where he'd spend an hour taking apart a lawnmower and self-
| deprecatingly call it nerdy to go into that detail. No! You
| could spend an hour explaining the metallurgy that goes into
| the case hardening on a single bolt or how the gear involutes
| are adjusted for the expected wear pattern and I'd find that
| more interesting than an hour skipping all the detail and,
| worse, pretending that was a deep dive.
| lucb1e wrote:
| Frankly that lawnmower thing sounds interesting as well, even
| if I'd find the JWST a lot _more_ interesting. It 's not not
| nerdy to look into lawnmower tech just because it's an
| everyday object or not your specific focus area :)
| adhesive_wombat wrote:
| It's not nerdy _enough_! I want a 10 part series on just
| the machine that sharpens the blades, and another on the
| engine oil, and another on the heat-resistant paint! None
| of these are my area, but all are fascinating in their own
| way.
| MBCook wrote:
| Could anyone explain what is special about the "pinch point"
| temperature?
| MAGZine wrote:
| IANAE, but it seems like the pinch point is the temp where the
| difference between your cooling fluid and instrument
| temperature is the lowest. in other words, this is where your
| cooling efficiency is lowest.
|
| This is probably doubly tricky at such low temperatures because
| the low average energy makes it difficult to even cool it
| further to begin with, never mind how cool the rest of your
| cooling systems need to be to actually sustain such low
| temperatures of your cooling brine to begin with.
|
| It took months to cool the instruments to these temperatures,
| but it could have taken even longer.
| Tozen wrote:
| Really glad that everything is progressing smoothly. Very much
| looking forward to what they might discover.
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