[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. ___________________________________________________________________ (page generated 2022-04-18 23:00 UTC)