16 ms·

James Webb telescope's coldest instrument reaches operating temperature

555 points by wglb 5y ago

belter 5y ago
"The Mid-Infrared Instrument for the James Webb Space Telescope" PDF: http://ircamera.as.arizona.edu/MIRI/paper1.pdf http://ircamera.as.arizona.edu/MIRI/paper1.pdf
sph 5y ago
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.
- WJW 5y ago
  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.
  - SkyMarshal 5y ago
    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.
    - TaylorAlexander 5y ago
      Unless they died out before we invented radio and all that exists now are their ancient structures!
      - SkyMarshal 5y ago
        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 5y ago
        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.
    - jandrese 5y ago
      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 5y ago
        We would still need continuous monitoring of the planets for decades, right? Or can we already make that out in a single snapshot?
        jandrese 5y ago
        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.
    - unrealhoang 5y ago
      How? 10 thousand years ago, I doubt our civilization signature is distinguishable. So unless they have FTL probe, we are still a harmless water/oxigen ball to them.
  - radicaldreamer 5y ago
    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 5y ago
      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.
      - inkblotuniverse 5y ago
        You're thinking too small. They'll come in and turn the solar system into a matrioshka brain. The aliens don't hate you, they don't love you, it's just that you (and the planet you're standing on, and the star it's orbiting) are made of atoms that can be used to build computers/more aliens.
    - ctoth 5y ago
      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 5y ago
        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 5y ago
      Maybe not now but in 100k years? Who knows.
  - tayo42 5y ago
    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 5y ago
      Does something exist if you can't/don't observe it?
      - carlio 5y ago
        If a tree falls in a forest and no one is around to hear it, does it make a sound?
        wglb 5y ago
        Don't know, but I have always wondered if the other trees laugh at it.
        ddingus 5y ago
        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 5y ago
        > 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.
    - pradn 5y ago
      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.
  - sph 5y ago
    Seeing them before they could see us would be ideal.
  - randomsilence 5y ago
    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.
  - JohnBooty 5y ago
    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 5y ago
      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 5y ago
        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.
      - brooksyd2 5y ago
  - jandrese 5y ago
    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.
    - omoikane 5y ago
      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 http://news.bbc.co.uk/2/hi/uk_news/8642558.stm
      - ncmncm 5y ago
        There is nothing we have that they haven't got, or could get overwhelmingly more easily than getting it from here.
        danlugo92 5y ago
        Our star is a pretty rare type, what if they want it whole D:.
        inkblotuniverse 5y ago
        We leave resources unexploited for our own aesthetic or economic reasons- it's uneconomical to mine every ore deposit, and we might not want to, if we value pristine land. Imagine you didn't care about the pristine land- let's ignore aesthetic reasons to hold back for a moment. As technology improves, it becomes easier to exploit resources. You can dig deeper with automated robots etc. Now imagine a technologically mature civilization: one whose tech is pushing the limits of physics. If our current ideas of physics are about right, you have to build things out of matter, and there's a finite amount of matter and negentropy out there. Conversely, right now, replication is cheap. Interstellar travel times are longer than civilisational lifetimes: ergo, most entities that arrive at other stars will have relatively mature technology. If I'm a super-civilisation/large-scale AI digging in for the long haul (till the end of the universe), what do I do? I put out all the stars, if I can, because they're wasteful. Negentropy is finite: we want to eke out every tiny bit of use there, not let hydrogen atoms fuse randomly out of our control. Large corporations viciously purse 0.1% efficiency gains because that amounts to millions of dollars at their scale. At the scale of the galaxy, 0.1% efficiency gains in your conversion of stars, planets, rocks and dust into things you care about is quadrillions of lives. The high travel time means the dynamics are different. You don't have to move from star to star: you can just build (number of solar systems)*(safe number of sentient self-replicating factory probes per system) probes in your home system, and send them out all at once (or as they roll off the line). Every solar system is a massive prize, every star left burning a travesty. If I'm turning the galaxy into stockpiled resources, I'm not going to leave any out that are profitable- and with mature tech, it's all profitable. There's no labor cost, after all.
  - Trasmatta 5y ago
    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.
  - marricks 5y ago
    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 5y ago
      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 5y ago
      Not really, they enslaved anyone they could and stole their resources. Murder only happened when the locals were in the way.
      - InitialLastName 5y ago
        You'll have to excuse me if it's hard for me to tell the difference between "a) enslave everyone, b) separate the men and the women, c) make the men mine metals with a ~1 year life expectancy, d) make the women work the sugarcane fields also with a ~1 year life expectancy, e) when you need more, take them from somewhere else" and a genocide.
  - jdjdjdjdjsjs 5y ago
    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 5y ago
      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 5y ago
  - deleted 5y ago
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  - api 5y ago
    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...
  - politelemon 5y ago
    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-problem https://www.goodreads.com/book/show/20518872-the-three-body-...
  - ddingus 5y ago
    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!
  - midrus 5y ago
    Err... We're literally this close to wipe out ourselves. I'd still take the discovering of an advanced civilization any day.
  - wetpaws 5y ago
    There is nothing wrong in alien civilization wiping out humanity.
  - cercatrova 5y ago
    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 5y ago
      This assumes that aliens building megastructures have as simplistic thinking as us.
      - WJW 5y ago
        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 5y ago
      https://arxiv.org/pdf/1302.0606.pdf https://arxiv.org/pdf/1302.0606.pdf
  - elihu 5y ago
    I think I would be a little bit relieved to discover that alien civilizations exist and they haven't destroyed us yet even though they probably could have. (Granted we haven't had radio very long, so it's possible they're just too far away to have detected us that way and they haven't explored the universe with whatever fine tooth comb is needed to have detected our pre-industrial civilization.)
  - panick21_ 5y ago
    > without any effort whatsoever If it was no effort, why do it? Its like, we could hunt don't people on some of the last unconnected islands and murder them. But why?
- BurningFrog 5y ago
  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!
baggy_trough 5y ago
Better source: https://blogs.nasa.gov/webb/ https://blogs.nasa.gov/webb/
jylam 5y ago
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.
- ResNet 5y ago
  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.
- CogitoCogito 5y ago
  This was an interesting article along those lines: https://arstechnica.com/science/2022/01/whats-left-for-the-webb-telescope-now-waggling-mirrors-turning-on-instruments/ https://arstechnica.com/science/2022/01/whats-left-for-the-w...
- gameswithgo 5y ago
  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.
  - jrootabega 5y ago
    We're all still traumatized by the meters/feet problem. Oops, I mean the Newtons/pounds problem.
  - pkaye 5y ago
    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.
  - lisper 5y ago
    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.
ResNet 5y ago
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.html https://webb.nasa.gov/content/about/innovations/cryocooler.h... [1] https://www.youtube.com/watch?v=aICaAEXDJQQ https://www.youtube.com/watch?v=aICaAEXDJQQ (The Insane Engineering of James Webb Telescope)
- Diederich 5y ago
  Yup, pretty much everything on this guy's channel is top drawer.
  - bXVsbGVy 5y ago
    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 https://www.youtube.com/c/ChristianReady [2] https://www.youtube.com/watch?v=Xv7QiNjx_MY https://www.youtube.com/watch?v=Xv7QiNjx_MY
  - dralley 5y ago
    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 5y ago
      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.
- neb_b 5y ago
  SmarterEveryDay also has a really interesting episode about the sun shield https://www.youtube.com/watch?v=Pu97IiO_yDI https://www.youtube.com/watch?v=Pu97IiO_yDI
punnerud 5y ago
“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 5y ago
  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 5y ago
    Heckin thermodynamics.
- rcxdude 5y ago
  No, it's an AC current (basically broadband noise). It provides no overall power, and further it's impossible to rectify it into a DC current with a diode at the same temperature (this is similar to why a wheel with a ratchet, even if microscopically sized, cannot extract work from the motion of particles at a constant temperature).
- ehsankia 5y ago
  I would assume the effects of this are extremely small, and only relevant due to how insanely precise JWST needs to be. I believe they said they were getting in the order of 1 photon per second from the dimmest targets, whereas your eye looking at a star in the sky gets millions of photons per second. When you're at that level, these small effects start actually introducing noise in your data, but otherwise the effect is so tiny I doubt it could be used for anything useful.
m3kw9 5y ago
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 5y ago
  JWST vs Spitzer in near infrared is a striking difference: https://twitter.com/gbrammer/status/1504369779540480002 https://twitter.com/gbrammer/status/1504369779540480002
  - floxy 5y ago
    That's a cool photo. Is there a similar comparison of that photo from the JWST to one done in visible light?
    - sbierwagen 5y ago
      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 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-m18-ax1000-ao127-2k.png https://bsrender.io/sample_renderings/hd84406-1deg-m18-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 http://cdsportal.u-strasbg.fr/?target=HD%20%2084406 Various sky surveys also show little detail at 2.2 arcmin.
      - sbierwagen 5y ago
        Math error: should be 73x73 pixels. (2000 pixels divided by 60 to get pixels per arcminute, then multiplied by 2.2 to get total pixels)
  - 5y ago
sgt101 5y ago
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 5y ago
  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.
Tozen 5y ago
Really glad that everything is progressing smoothly. Very much looking forward to what they might discover.
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dwighttk 5y ago
Finally…
MBCook 5y ago
Could anyone explain what is special about the “pinch point” temperature?
- MAGZine 5y ago
  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.
lucb1e 5y ago
The list of cool programs approved is astounding: https://www.stsci.edu/jwst/science-execution/approved-programs/cycle-1-go 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 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 5y ago
  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.
polishdude20 5y ago
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 5y ago
  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 5y ago
    Oh for sure, if you've got the money to break things at the hobby level :)
    - Aperocky 5y ago
      SpaceX is profitable, they are profitable because they broke lots of things before it actually worked. This is a valid strategy.
      - polishdude20 5y ago
        No doubt. At the hobby level, doing this as a hobby, profit isn't a thing I'm going for.
colordrops 5y ago
Will the JWT be able to see the actual shape of stars and planets rather than just points of light?
- Jabbles 5y ago
  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 https://en.wikipedia.org/wiki/Parsec Angular resolution of JWST: https://jwst.nasa.gov/content/about/faqs/faq.html#sharp https://jwst.nasa.gov/content/about/faqs/faq.html#sharp
  - colordrops 5y ago
    Thanks
- pkaye 5y ago
  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 https://roman.gsfc.nasa.gov/exoplanets_direct_imaging.html
- floxy 5y ago
  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://www.youtube.com/watch?v=NQFqDKRAROI https://arxiv.org/abs/1802.08421 https://arxiv.org/abs/1802.08421
marina123456 5y ago
Interesting!
- marina123456 5y ago
  Sorry for the excitment
  - Joel1234 5y ago
    Dont be sorry
jonahbenton 5y ago
Astonishing, heroic work. An ultrabright star in an otherwise dark, grim world.
brazzy 5y ago
> long with Webb's three other instruments, MIRI initially cooled off in the shade of Webb's tennis-court-size sunshield, dropping to about 90 kelvin (minus 298 F, or minus 183 C). But dropping to less than 7 kelvin required an electrically powered cryocooler. This seems hard to believe - I get that you have a bunch of radiation flying around (including IR from the sunshield itself) that prevents passively cooling off to 0K (or the CBR's 3K) - but 90K? Is the space itself around L2 really effectively that "hot"? Or is it that passive cooling would just get intolerably slow and you might just as well deploy the tech you need to go from whatever the equilibrium is to below 7K earier?
peilinni 5y ago
i like ur telescope

555 points by wglb 5y ago

"The Mid-Infrared Instrument for the James Webb Space Telescope" PDF: http://ircamera.as.arizona.edu/MIRI/paper1.pdf http://ircamera.as.arizona.edu/MIRI/paper1.pdf

sph 5y ago

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.

WJW 5y ago
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.
- SkyMarshal 5y ago
  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.
  - TaylorAlexander 5y ago
    Unless they died out before we invented radio and all that exists now are their ancient structures!
    - SkyMarshal 5y ago
      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 5y ago
        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.
  - jandrese 5y ago
    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 5y ago
      We would still need continuous monitoring of the planets for decades, right? Or can we already make that out in a single snapshot?
      - jandrese 5y ago
        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.
  - unrealhoang 5y ago
    How? 10 thousand years ago, I doubt our civilization signature is distinguishable. So unless they have FTL probe, we are still a harmless water/oxigen ball to them.
- radicaldreamer 5y ago
  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 5y ago
    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.
    - inkblotuniverse 5y ago
      You're thinking too small. They'll come in and turn the solar system into a matrioshka brain. The aliens don't hate you, they don't love you, it's just that you (and the planet you're standing on, and the star it's orbiting) are made of atoms that can be used to build computers/more aliens.
  - ctoth 5y ago
    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 5y ago
      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 5y ago
    Maybe not now but in 100k years? Who knows.
- tayo42 5y ago
  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 5y ago
    Does something exist if you can't/don't observe it?
    - carlio 5y ago
      If a tree falls in a forest and no one is around to hear it, does it make a sound?
      - wglb 5y ago
        Don't know, but I have always wondered if the other trees laugh at it.
        ddingus 5y ago
        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 5y ago
      > 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.
  - pradn 5y ago
    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.
- sph 5y ago
  Seeing them before they could see us would be ideal.
- randomsilence 5y ago
  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.
- JohnBooty 5y ago
  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 5y ago
    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 5y ago
      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.
    - brooksyd2 5y ago
- jandrese 5y ago
  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.
  - omoikane 5y ago
    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 http://news.bbc.co.uk/2/hi/uk_news/8642558.stm
    - ncmncm 5y ago
      There is nothing we have that they haven't got, or could get overwhelmingly more easily than getting it from here.
      - danlugo92 5y ago
        Our star is a pretty rare type, what if they want it whole D:.
      - inkblotuniverse 5y ago
        We leave resources unexploited for our own aesthetic or economic reasons- it's uneconomical to mine every ore deposit, and we might not want to, if we value pristine land. Imagine you didn't care about the pristine land- let's ignore aesthetic reasons to hold back for a moment. As technology improves, it becomes easier to exploit resources. You can dig deeper with automated robots etc. Now imagine a technologically mature civilization: one whose tech is pushing the limits of physics. If our current ideas of physics are about right, you have to build things out of matter, and there's a finite amount of matter and negentropy out there. Conversely, right now, replication is cheap. Interstellar travel times are longer than civilisational lifetimes: ergo, most entities that arrive at other stars will have relatively mature technology. If I'm a super-civilisation/large-scale AI digging in for the long haul (till the end of the universe), what do I do? I put out all the stars, if I can, because they're wasteful. Negentropy is finite: we want to eke out every tiny bit of use there, not let hydrogen atoms fuse randomly out of our control. Large corporations viciously purse 0.1% efficiency gains because that amounts to millions of dollars at their scale. At the scale of the galaxy, 0.1% efficiency gains in your conversion of stars, planets, rocks and dust into things you care about is quadrillions of lives. The high travel time means the dynamics are different. You don't have to move from star to star: you can just build (number of solar systems)*(safe number of sentient self-replicating factory probes per system) probes in your home system, and send them out all at once (or as they roll off the line). Every solar system is a massive prize, every star left burning a travesty. If I'm turning the galaxy into stockpiled resources, I'm not going to leave any out that are profitable- and with mature tech, it's all profitable. There's no labor cost, after all.
- Trasmatta 5y ago
  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.
- marricks 5y ago
  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 5y ago
    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 5y ago
    Not really, they enslaved anyone they could and stole their resources. Murder only happened when the locals were in the way.
    - InitialLastName 5y ago
      You'll have to excuse me if it's hard for me to tell the difference between "a) enslave everyone, b) separate the men and the women, c) make the men mine metals with a ~1 year life expectancy, d) make the women work the sugarcane fields also with a ~1 year life expectancy, e) when you need more, take them from somewhere else" and a genocide.
- jdjdjdjdjsjs 5y ago
  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 5y ago
    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 5y ago
- deleted 5y ago
  [deleted]
- api 5y ago
  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...
- politelemon 5y ago
  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-problem https://www.goodreads.com/book/show/20518872-the-three-body-...
- ddingus 5y ago
  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!
- midrus 5y ago
  Err... We're literally this close to wipe out ourselves. I'd still take the discovering of an advanced civilization any day.
- wetpaws 5y ago
  There is nothing wrong in alien civilization wiping out humanity.
- cercatrova 5y ago
  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 5y ago
    This assumes that aliens building megastructures have as simplistic thinking as us.
    - WJW 5y ago
      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 5y ago
    https://arxiv.org/pdf/1302.0606.pdf https://arxiv.org/pdf/1302.0606.pdf
- elihu 5y ago
  I think I would be a little bit relieved to discover that alien civilizations exist and they haven't destroyed us yet even though they probably could have. (Granted we haven't had radio very long, so it's possible they're just too far away to have detected us that way and they haven't explored the universe with whatever fine tooth comb is needed to have detected our pre-industrial civilization.)
- panick21_ 5y ago
  > without any effort whatsoever If it was no effort, why do it? Its like, we could hunt don't people on some of the last unconnected islands and murder them. But why?
BurningFrog 5y ago
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!

baggy_trough 5y ago

Better source: https://blogs.nasa.gov/webb/ https://blogs.nasa.gov/webb/

jylam 5y ago

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.

ResNet 5y ago
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.
CogitoCogito 5y ago
This was an interesting article along those lines: https://arstechnica.com/science/2022/01/whats-left-for-the-webb-telescope-now-waggling-mirrors-turning-on-instruments/ https://arstechnica.com/science/2022/01/whats-left-for-the-w...
gameswithgo 5y ago
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.
- jrootabega 5y ago
  We're all still traumatized by the meters/feet problem. Oops, I mean the Newtons/pounds problem.
- pkaye 5y ago
  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.
- lisper 5y ago
  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.

ResNet 5y ago

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.html https://webb.nasa.gov/content/about/innovations/cryocooler.h... [1] https://www.youtube.com/watch?v=aICaAEXDJQQ https://www.youtube.com/watch?v=aICaAEXDJQQ (The Insane Engineering of James Webb Telescope)

Diederich 5y ago
Yup, pretty much everything on this guy's channel is top drawer.
- bXVsbGVy 5y ago
  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 https://www.youtube.com/c/ChristianReady [2] https://www.youtube.com/watch?v=Xv7QiNjx_MY https://www.youtube.com/watch?v=Xv7QiNjx_MY
- dralley 5y ago
  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 5y ago
    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.
neb_b 5y ago
SmarterEveryDay also has a really interesting episode about the sun shield https://www.youtube.com/watch?v=Pu97IiO_yDI https://www.youtube.com/watch?v=Pu97IiO_yDI

punnerud 5y ago

“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 5y ago
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 5y ago
  Heckin thermodynamics.
rcxdude 5y ago
No, it's an AC current (basically broadband noise). It provides no overall power, and further it's impossible to rectify it into a DC current with a diode at the same temperature (this is similar to why a wheel with a ratchet, even if microscopically sized, cannot extract work from the motion of particles at a constant temperature).
ehsankia 5y ago
I would assume the effects of this are extremely small, and only relevant due to how insanely precise JWST needs to be. I believe they said they were getting in the order of 1 photon per second from the dimmest targets, whereas your eye looking at a star in the sky gets millions of photons per second. When you're at that level, these small effects start actually introducing noise in your data, but otherwise the effect is so tiny I doubt it could be used for anything useful.

m3kw9 5y ago

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 5y ago
JWST vs Spitzer in near infrared is a striking difference: https://twitter.com/gbrammer/status/1504369779540480002 https://twitter.com/gbrammer/status/1504369779540480002
- floxy 5y ago
  That's a cool photo. Is there a similar comparison of that photo from the JWST to one done in visible light?
  - sbierwagen 5y ago
    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 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-m18-ax1000-ao127-2k.png https://bsrender.io/sample_renderings/hd84406-1deg-m18-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 http://cdsportal.u-strasbg.fr/?target=HD%20%2084406 Various sky surveys also show little detail at 2.2 arcmin.
    - sbierwagen 5y ago
      Math error: should be 73x73 pixels. (2000 pixels divided by 60 to get pixels per arcminute, then multiplied by 2.2 to get total pixels)
- 5y ago

sgt101 5y ago

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 5y ago
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.

Tozen 5y ago

Really glad that everything is progressing smoothly. Very much looking forward to what they might discover.

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dwighttk 5y ago

Finally…

MBCook 5y ago

Could anyone explain what is special about the “pinch point” temperature?

MAGZine 5y ago
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.

lucb1e 5y ago

The list of cool programs approved is astounding: https://www.stsci.edu/jwst/science-execution/approved-programs/cycle-1-go 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 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 5y ago
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.

polishdude20 5y ago

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 5y ago
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 5y ago
  Oh for sure, if you've got the money to break things at the hobby level :)
  - Aperocky 5y ago
    SpaceX is profitable, they are profitable because they broke lots of things before it actually worked. This is a valid strategy.
    - polishdude20 5y ago
      No doubt. At the hobby level, doing this as a hobby, profit isn't a thing I'm going for.

colordrops 5y ago

Will the JWT be able to see the actual shape of stars and planets rather than just points of light?

Jabbles 5y ago
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 https://en.wikipedia.org/wiki/Parsec Angular resolution of JWST: https://jwst.nasa.gov/content/about/faqs/faq.html#sharp https://jwst.nasa.gov/content/about/faqs/faq.html#sharp
- colordrops 5y ago
  Thanks
pkaye 5y ago
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 https://roman.gsfc.nasa.gov/exoplanets_direct_imaging.html
floxy 5y ago
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://www.youtube.com/watch?v=NQFqDKRAROI https://arxiv.org/abs/1802.08421 https://arxiv.org/abs/1802.08421

marina123456 5y ago

Interesting!

marina123456 5y ago
Sorry for the excitment
- Joel1234 5y ago
  Dont be sorry

jonahbenton 5y ago

Astonishing, heroic work. An ultrabright star in an otherwise dark, grim world.

brazzy 5y ago

> long with Webb's three other instruments, MIRI initially cooled off in the shade of Webb's tennis-court-size sunshield, dropping to about 90 kelvin (minus 298 F, or minus 183 C). But dropping to less than 7 kelvin required an electrically powered cryocooler. This seems hard to believe - I get that you have a bunch of radiation flying around (including IR from the sunshield itself) that prevents passively cooling off to 0K (or the CBR's 3K) - but 90K? Is the space itself around L2 really effectively that "hot"? Or is it that passive cooling would just get intolerably slow and you might just as well deploy the tech you need to go from whatever the equilibrium is to below 7K earier?

peilinni 5y ago

i like ur telescope