[ResNet]

The fact that the telescope's cryocooler is acoustically symmetrical such that any vibrations made by each cylinder, and the actual flow of gas, is near-perfectly cancelled out is nothing short of amazing. [0]

Real Engineering made a video that covered this and more, which is well worth a watch. [1]

[0] https://webb.nasa.gov/content/about/innovations/cryocooler.h...

[1] https://www.youtube.com/watch?v=aICaAEXDJQQ (The Insane Engineering of James Webb Telescope)

[_fizz_buzz_]

This is the kind of thing I would never come up with and if I did I would never think it would be possible to implement. There are some seriously ingenious people out there.

[sslayer]

Teams, seriously ingenious teams.

[elzbardico]

Ideas never come from teams but from individuals. Teams implement, help to refine, other team members improve upon the idea with their own ideas. But the act of creation, is something done by an individual. Teams are not good at innovation, design by committee can only give us mediocrity

[atty]

I work in nuclear physics and no one of our experiments could be designed by a single person. They’re far too large and complicated, and even relatively simple sub-parts are multi-year, multi-million dollar undertakings.

Furthermore, even the ideas of “let’s use X to measure Y” are VERY rarely completely new and unheard of ideas from a single individual. Far more common that those ideas come from long term collaboration/discussions between multiple field experts.

[FridgeSeal]

I think this is a bit reductive.

I’ve definitely been a part of teams where we came up with ideas as a team. Individuals contributed, but the actual innovation came from the collective bouncing back-and-forth of ideas.

We could get pedantic and say “it was still individuals coming up with the ideas” but that’s needlessly splitting hairs and in my experience it’s the team environment/cohesion that facilitates people coming up with said ideas.

[groby_b]

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".

[guelo]

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.

[seabird]

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.

[kcarter80]

> I've seen plenty of very promising electrical and mechanical designs that might have seriously affected their market segment

Like what?

[seabird]

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.

[swader999]

I would disagree. Often leaps occur when two or three people with their heads in a problem just loosely bounce ideas around.

[vlovich123]

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.

[patmorgan23]

An implementation takes a thousand ideas refined and fitted together to solve a hundred problems.

[Cthulhu_]

There are, but they are rarely in an environment where they can use their ingenuity to their full extent; there's often budget and time constraints.

I mean I'm not saying there weren't any with these things, but they had a lot more leeway than in your average 9-5.

[tempodox]

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.

[mywacaday]

This video https://youtu.be/5MxH1sfJLBQ was posted here https://news.ycombinator.com/item?id=30729109 about how the actuators work on the James Webb telescope. It's a great watch.

[dav_Oz]

Robert Warden (original author of the paper "Cryogenic nano-actuator" (2006)[0]) did the first prototyping with Lego Technic [1]. From Lego to the JWST, I mean damn, like childhood dreams come true (:

[0]https://www.esmats.eu/amspapers/pastpapers/pdfs/2006/warden....

[1]https://m.youtube.com/watch?v=3WBrqUa_1yk

[beambot]

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?)

[phinnaeus]

Why are you supposing that the two halves of the coupler are moving apart? They are both attached to the moving section

[beambot]

Figure 9 implies that the coupler drives the blue gear (shaft of lead screw).

But let's assume you are right: Then how does the blue gear at top of the lead screw simultaneously turn the shaft and move upwards too?

[Linosaurus]

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.

[formerly_proven]

https://www.youtube.com/watch?v=5MxH1sfJLBQ

[dredmorbius]

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.

https://en.wikipedia.org/wiki/Ball_Corporation

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.

https://en.wikipedia.org/wiki/Indiana_gas_boom

[nomel]

How is the position/correctness sensed? Do they calibrate based on the image of a known star (or something)?

[simonh]

Mirror alignment is measured using a laser reflected off the mirror segments into an interferometer.

https://www.nasa.gov/feature/goddard/2017/aligning-the-prima...

[nomel]

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.

[simonh]

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.

[nomel]

I don't see anything that suggests a laser is being used in space. At 1:24 in the video, it says starlight is used. Only stars are mentioned in the press releases: https://www.universetoday.com/154623/heres-exactly-how-engin...

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.

Interferometry works just fine with starlight.

[hi41]

Thank you for posting this. It looks like Robert Warden who wrote the paper really liked the video.

[neb_b]

SmarterEveryDay also has a really interesting episode about the sun shield

https://www.youtube.com/watch?v=Pu97IiO_yDI

[JohnBooty]

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.

A number of Apple devices employ this technique, like the new iMacs. I know the 2019 (and presumably, the 2021) 16" MBPs do: https://thenextweb.com/news/the-new-imacs-have-force-canceli...

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.

[grishka]

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

[JohnBooty]

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"

https://www.apple.com/newsroom/2021/10/apple-unveils-game-ch...

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.

[Cthulhu_]

I've blocked Russian IPs from my website because the vast majority of spambots had a Russian IP.

Anyway yeah, I was already impressed with these little portable speakers.

[sacrosancty]

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.

[akira2501]

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.

[sacrosancty]

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.

[XorNot]

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.

[1] https://eyeofmidas.com/scifi/Turtledove_RoadNotTaken.pdf

[ramraj07]

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.

[Diederich]

Yup, pretty much everything on this guy's channel is top drawer.

[dralley]

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]

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.

[bXVsbGVy]

The Launch Pad Astronomy is another great source for astronomic content [1]. I found pretty awesome the live show about JWST done with NASA scientists [2].

[1] https://www.youtube.com/c/ChristianReady [2] https://www.youtube.com/watch?v=Xv7QiNjx_MY

[throwthere]

Kind of like a flat four or six engine versus inline/V6.

[red369]

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)

[roamerz]

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

[t0mas88]

The 6 in-line is the least vibrating one of the options, but the 4 is very close.

[red369]

Were you including flat engines in that statement? Like, an online 6 is better balanced than a flat 6? If not, do you happen to know how a flat 6 compared with an inline 6 for vibrations/balance? A quick search didn’t find me anything. I know flat engines have to offset the cylinders a little.

[nickff]

Inline sixes are better-balanced than flat sixes.

[AceJohnny2]

Motorcycles have a similar constraint, so I'm a little blasé on the technique.