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]
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.
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
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.
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.
When people call teamwork "design by committee", it's time to move on - you know you've accumulated a prima donna or three when that happens.
Ideas on large projects are almost always collaborative. There's never just one spark of insight - you've talked about the problem for a long time, and the whole team slowly chipped away at "but we can't do that because X, Y, Z".
The idea of a single genius motivating it belies pretty much every large project in existence. (Based on personal experience, the threshold where it's not just a single person having the crucial breakthroughs seems to be at projects requiring teams of ~20+ persons)
You solve problems via "Yes, and", not via "behold the genius".
It's not about prima donnas, it's a political ideology. A close-minded ideology about the heroicness of individuals and the degeneracy of any collective.
An idea by itself is generally worth jack shit in most lines of business. People have actually game-changing ideas all the time that go nowhere because a team wasn't/couldn't be allocated to develop that idea to the point where it matters. I've seen plenty of very promising electrical and mechanical designs that might have seriously affected their market segment go to the graveyard because of lack of resources to develop that design. Somebody writing software might have a decent chance of single-handedly creating something that makes some noise in the field, but most people in science and technology couldn't come close even if they dedicated their life to it.
You might be right in the strictest sense that an idea comes from one person, but it's a largely worthless observation, because the idea gets you absolutely nothing without the work.
They were mostly related to fuel storage and delivery for a certain segment of vehicles. I'll save the specifics because my employer would be pretty easily identifiable. Ultimately, it's not really relevant; this is common, even in software, where one person stands a chance of single-handedly carrying a product. Maybe there's not be enough engineering time available outright. Maybe the group can't take a risk on allocating resources on a promising idea that might not pan out. Maybe other non-engineering resources in the company are tied up with other projects and can't bring it to market, even if you did pursue it. I'm sure if you think hard enough you can think of multiple products that were genuinely good and had a future, but ultimately died because of a lack of a team that would follow through on developing it.
I’ve seen both. I’ve seen individuals pull magic out of their ass. I’ve also seen teams innovate. The latter though really happens when there’s a shared vision and domain experts from different parts are tackling disparate parts of the problem. That usually looks like “we’ll if I had X, y could be really easy” “oh I solved most of X a while ago but I’m stuck on this little part” etc. I don’t think I’ve observed team innovation directly but I’m sure it’s possible or I didn’t look correctly.
However. The most important part of innovation on a large project. Getting the team motivated by the vision and having each individual feel free to try to innovate. Otherwise individual problems being solved mean jack all and no single individual is going to build a very complicated project. There are some people who try but they are quickly outrun by dedicated teams. At a minimum it’s to have team members help you stay focused and motivated when you have moments of disbelief.
There is a good case for holding diverse hiring practices in high esteem:
* Heterogeneity of ideas is moderately correlated to diversity of backgrounds
* Diverse teams are less prone to groupthink, more ready to acknowledge and correct for their biases, and they more readily challenge one another on a factual basis
* Hiring practices that try to offset structural biases and personal tendencies towards uniformity can access talent pools that others do not
To sum up, disregarding any political or social viewpoint, diversity is a strong value driver.
As for "intelligence", whatever that is; insofar as it can even be qualified, let alone quantified, this remains a minimal contributor to performance beyond the second sigma. Genius is contextual.
Source: me, have joined/managed high performance tech-sector teams, including extraordinary individuals from unusual/outlier backgrounds.
It seems straightforward that cancelling internal vibrations as far as possible is a factor in the cooling, because warmth is movement (Brownian motion), and vice versa.
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 (:
I'm having a hard time understanding the axial motion from the coarse adjustment. From [0]: The Ball Screw in Figure 9 has a 21 mm range. As the ball screw nut moves up, the housing moves up too -- but then the two halves of the tumbler coupling get displaced in such a way that doesn't seem to support a 21mm displacement. How does the tumbler coupling stay mated? (I feel like I'm missing something obvious?)
I believe that everything in figure nine moves together vertically except the yellow/orange ball screw nut and pink horizontal thingie, these are fixed to the satellite.
The sensor and stabilizer on the right side are flexible.
Ball Aerospace, the manufacturer of the actual JWST actuators, traces its history to the Ball Corporation, of Ball Jar fame, which had relocated its manufacturing operations from Buffalo, NY, to Muncie, IN, following cheap fuel.
That move was made on account of the Indian Gas Boom, which ran from the 1880s through the early 20th century, when it was discovered that there were large reserves of readily-accessible natural gas to be found in Indiana in field generally centered around Muncie.
As with other natural resource extraction booms before and since, proponents argued that the resources were inexhaustible, that prospectors had freedom to use or waste the resource in any way they saw fit --- large natural torches called flambeaux were a frequent sight. Over 90% of the gas was ultimately wasted, vented to the atmosphere.
The boom died out in the first decade of the 20th century.
It appears that a star is used, while in space, with the laser being used as an artificial star. I only see this directly mentioned in the video (1:24), and indirectly in the text, "thus acting like a source of artificial starlight". I guess this makes sense, as it's the only way to do it "end-to-end" while in space.
There are actually two stages of calibration in space. The first stage is aligning the mirrors, using direct measurement of the mirror alignment with the interferometer, after they are unfolded from their unaligned stowed positions.
> To measure the shape of the Webb telescope’s primary mirror, engineers use a test device called an interferometer, which shines a laser down onto the mirror.
The next phase you’re referring to also uses a laser, but this time it’s shone off the mirrors into the actual scientific observation sensors, hence they describe it as being used as a source of artificial starlight.
On the ground, you can easily place a laser in an optically identical position as a star (near infinity). In space, I don't think this would be possible, since it would require that the laser, and the optics that would be required, would all be within a fraction of a wavelength of the true optical path. In the end, you would still need to align to a star anyways.
On a much less impressive (though more acccessible, at least for those of us who don't get to tool around with space telescopes on a regular basis) a similar technique is actually pretty common in consumer audio applications.
It's popular in higher-end subwoofers. While not the cheapest solution, a whole host of design issues is solved by simply adding a second amplifier and a second driver firing in the other direction. https://us.kef.com/kf92-subwoofer.html
If I'm not mistaken a fair number of portable Bluetooth speakers use something similar. If you're hearing a surprising amount of rattle-free bass come from a device that seems too small to pull it off, there's a decent chance they're using dual opposed drivers.
Do they use this in the 2021 MacBooks too? The thing sounds almost like it should not be physically possible to pack this much bass into such a thin device.
p.s. I'm so tired of random websites blocking Russian IPs because reasons
Yeah, it seems the 2021 MBPs use a similar system:
"A high-fidelity six-speaker sound system features two tweeters for a clearer soundstage and four force-cancelling woofers, resulting in 80 percent more bass"
I'm not sure what this "80% more bass" claim is in comparison to. But the 2019 models are definitely impressive. I'm looking forward to hearing the 2021 at some point.
I have a feeling that a huge amount of common engineering ideas that we all see as common sense, like gears, linkages, pistons, even the wheel, would have been beyond the imagination of most people before they were invented. I'd say we only know them because we've seen them. This other stuff might be common knowledge among specialists in that field, or not.
That's where I really love James Burke's "Connections" TV series, it somewhat dispels this idea by showing just how interconnected discoveries and inventions were even in a far earlier age. One invention makes a new way of making money possible, this new way of making money comes with entirely new challenges and the capital to solve them. Unsurprisingly people naturally align themselves to solve these problems and capture some of that capital.
The idea of the "lone inventor" is a lovely one.. but I submit that they have not been the majority of force behind much of the invention our world now enjoys. Humanity itself is an iterative process.
Oh, I agree. I'm not saying nobody else would have invented them, but I think you'd have to put some expensive work into inventing even a wheel, not just causally imagine it whenever the need came up like we would do today. A lot of technology is really ingenious but it would surely have been invented by somebody the moment it became economically valuable to do so.
The Road Not Taken[1] short story tends to stick in my mind because of that. There's a lot of ideas that are extremely obvious once you see them, but without the prompt you might never get there.
That’s the beauty of technology though. Once someone figures out something, no matter how inexplicable, the mere suggestion of the possibility is enough to propagate a new normal where everyone assumes it’s pedestrianness.
The atom bomb, nuclear power, iPhones , the list is endless indeed.
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.
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.
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].
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)
Not necessarily. If memory serves GM had a V6 in the 70’s or 80’s that had offset crank journals to make each firing stroke 120 degrees apart. I think it was the 4.3
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.
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.
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.
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.
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.
I guess the GP means US customary degrees rather than standard ones (also technically kelvins are not "degrees", the unit is simply K rather than °K, but as they share the magnitude with °C the difference gets muddled when talking about relative temperatures…)
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).
Sure, but when we’re talking about NASA the context is quite different from random software “engineering” projects, or even random traditional engineering projects. For NASA cost overruns don’t usually seem to lead to cases of sunk cost fallacy, and their infamous late-90s attempt at “better, faster, cheaper” rather ended up demonstrating how you can have any two of those three, and arguably, in the case of “never done before” flagship projects, only one of them.
It is still true though that many times bad planning and management has been at least a partial cause of cost/schedule overrund at NASA, and they’ve received well-justified criticism for it from both internal and external auditors.
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.
No specific inside info. But seeing how the sausage is made makes it amazing that anything they do works at all, let alone that it so often works as well as it does. I was particularly primed to expect JWST to fail because I lived through the Galileo antenna failure and the Hubble mirror fiasco.
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.
> 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?
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.
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.
The YouTube channel for the Hubble Space Telescope and James Webb Telescope have a lot of interesting content. Scientists and Engineers do presentations about the science and technology.
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 :)
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.
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.
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.
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.
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.
>"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.
When you're sample size is 1 it's wrong to assume that the general population is exactly like your sample. Of course, it's slightly more wrong to assume the general population is nothing like your sample.
It's entirely reasonable to assume that any life that evolves under resource constraints will have violent competition somewhere in whatever means of intergenerational data transport they use.
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.
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.
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.
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.
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!
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 :)
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.
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?
> 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.
My thinking is that if you have a rock headed your way at say 10% of lightspeed or so, pretty much anything you can do to it past a certain point is mostly just going to change what form of matter smacks into your planet.
Maybe my mental model for how that works is wrong, but I'm just picturing a dust/rubble cloud at 10% of c irradiating the planet with xrays or something due to whatever extreme friction interaction happens in the atmosphere.
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.
> 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.
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.
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?
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.
We don't worry too much about killing an ant colony. Which always feels like it should be different when "sentient" beings are involved, but humans are so limited that beyond 150 people we struggle to conceptualize of other sentient minds as "real".
So really it could go either way: alien intelligence so advanced and vast that we don't seem meaningfully alive to it, or alien intelligence so advanced and vast that man's inhumanity to man makes us seem impossibly savage and dangerous.
> 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.
>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.
You need to stick the tiny maneuvering thrusters to it in any case. Or maybe just some light sails will do the trick at those distances, depending on how good your aim with the primary means of propulsion was.
If humanity was doing this, we'd likely attach propulsion and accelerate the entire way anyways. Unless there's some new drive technology discovered by then or we hijack something natural/environs to do it for us.
> 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.
It’s only impossible under our current understanding of physics, which on the scale of humanity is a brief little slice of time. A hundred years from now who knows what discoveries we will find that either bypass FTL travel or change our understanding of the universe so much that “time and distance” become irrelevant.
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.
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.
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.
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.
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.
Don't worry, they'll be overtaken by a 1kg lump of computers, self-replication machinery, and propellant crewed by sapient AI/digitised humans and offered a pickup. Virtual passengers only, though, sorry...
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
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.
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.
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.
. 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".
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.
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?
> 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.
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?
Rather, you shouldn't fear a doctor's visit because if you learn you had cancer, well, you'd have it whether you knew or not, but now you know and can act. Of course, if there was nothing to do about the cancer but wait to die, and nothing to do about the aliens but wait for their bombs to arrive, then you may prefer not visiting the doctor or looking through the telescope.
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)
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.
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.
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.
Or perhaps its just incredibly automated. I'm sure a civilization that advanced could at the very least automated the mining aspects, if not the actual construction.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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-...
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.)
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...
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.
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.
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.
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.
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.
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.
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.
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...
> 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?
“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.”
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).
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.
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.
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.
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.
The JWST contains entirely different class of equipment, none of the likes has been included before. It also includes some of the largest equipment, huge mirrors that are capable of capturing huge quantities of light.
Because of the frequency it is planning on looking at (enabled by how cold they're making the instruments), and because of the size of the mirrors (more light from dim sources), the JWST is going to be able to see waayyyy further, more dim, more old objects than any other telescope before. This is why the JWST is so exciting at all. It's going to tell us a LOT about the early history of the Universe.
The JWST is not about putting the iPhone 13 in space when we already have an iPhone 12. It's more akin to putting an X-Ray camera on the iPhone. Actually, "that telescope but more," projects are few and far between these days: most agencies aren't interested in doing "the same but a little more,"--most projects optimize for where the biggest difference can be made in science.
As an aside, you downplay the importance of angular resolution. If we're talking about visible light, having a space telescope take a picture of a galaxy in the visible spectra is obviously different and more useful than your phone/eye capture the "same" photons. Extra resolution is always enlighting because it provides us more information. Maybe that single point of light is actually not a single point of light, for example.
Well, it'll be able to take direct photos of exoplanets and give us the data to analyze their atmospheres for signs of life. They photos won't look like much, but if any of the planets do end up having signs of life, that'll be far more thrilling than any pretty space photo could ever be.
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.
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.
