Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

We're building computers wrong [video]

youtube.com

Post reply on HN
Print view View original

51–60 of 83 posts

Re: We're building computers wrong [video]

#51

Post by eternityforest »

autokad wrote: post #37
eternityforest wrote: post #30

Earlier quoted context omitted.

People always love to say some old lost tech is better than the modern version But it's like, a one in a thousand shot.Almost all modern tech is better with regressions lasting a decade at most. Occasionally there are rumors of some modern medical treatments being worse even though medicine as a whole improves, but mechanical and electrical stuff is much better understood and more controlled. The exception is a few s…

The analog computers on the Missouri class battleships was never upgraded because the kill radius of the shells was larger than the margin of error the analog computers introduced and that the analog computers required less electricity which is good for something such as a ship. So in this way, yes, they are better (these computers developed in the 30s). It depends on the application. > Occasionally there are rumors…

People died going to the moon the first time. Better to not go at all, or to have it cost 10x as much, than to risk even one astronaut's life.

Besides, if we just redid what we had, we would not be developing any new tech that could be used on earth. And it would be less comfortable, a very bad thing if you're still fighting the losing battle to convince anyone that they'd like to be in space for more that a brief adventure.

AFAIK they have cuirass ventilation to replace iron lungs now.

Those new tractors are most likely way more reliable. In practice they may be worse because of artificial limitations put there on purpose, but were it not for those it would almost certainly be better(Although people would probably still like the same ones, because no matter how reliable something is, people seem to like things with a "substantial" feel that they can understand).

Re: We're building computers wrong [video]

#52

Post by ben_w »

autokad wrote: post #37
eternityforest wrote: post #30

Earlier quoted context omitted.

People always love to say some old lost tech is better than the modern version But it's like, a one in a thousand shot.Almost all modern tech is better with regressions lasting a decade at most. Occasionally there are rumors of some modern medical treatments being worse even though medicine as a whole improves, but mechanical and electrical stuff is much better understood and more controlled. The exception is a few s…

The analog computers on the Missouri class battleships was never upgraded because the kill radius of the shells was larger than the margin of error the analog computers introduced and that the analog computers required less electricity which is good for something such as a ship. So in this way, yes, they are better (these computers developed in the 30s). It depends on the application. > Occasionally there are rumors…

All the commentary I see about the moon program says that the rockets bit of NASA was set up to be a pork barrel for all of Congress just so nobody cancelled the Apollo mission, and that the many people are annoyed that this structure is still in place.

Given that, the cost of the latest moon mission is “as much as we can squeeze the taxpayer for” rather than representative of the actual cost. The various new startups worldwide (not just SpaceX) are all much more interesting, though obviously they’ll only get a price comparison when they actually land a human.

I think it would’ve been neat if the Falcon Heavy had speed-run the Lunar X Prize, but alas they had better things to do: https://space.stackexchange.com/questions/27271/could-the-lu...

Re: We're building computers wrong [video]

#53

Post by mikewarot »

Let's use the LM358DT as an example of a modern op-amp. Just sitting there, it has current sources sinking 100uA of current. At 5 volts, it consumes about 0.7 mA with no load.

So, compare that to a 4 bit ALU (an old one, at that) the 74HC181. At 5 volts it consumes 80uA at idle.

Analog circuits require transistors have bias flows through them at all times to ensure linearity. CMOS digital logic has the transistors either fully on or off, except during switching times.

Going analog isn't as great an option as this video makes it seem.

Re: We're building computers wrong [video]

#54

Post by tonfreed »

austinl wrote: post #47
eternityforest wrote: post #30

Earlier quoted context omitted.

People always love to say some old lost tech is better than the modern version But it's like, a one in a thousand shot.Almost all modern tech is better with regressions lasting a decade at most. Occasionally there are rumors of some modern medical treatments being worse even though medicine as a whole improves, but mechanical and electrical stuff is much better understood and more controlled. The exception is a few s…

The ancient tech myth I see the most is the idea that the recipe for "Roman concrete" was lost, and somehow modern engineers can't figure out how to make a superior mix. Certainly, Roman engineers built incredible unreinforced concrete structures. But this was accomplished through structural engineering techniques designed to keep the concrete compressed (e.g. arches, domes). Modern structures like elevated highways…

I just want a Damascus steel sword because they look cool

Re: We're building computers wrong [video]

#55

Post by LordDragonfang »

mannykannot wrote: post #41
autokad wrote: post #38

Earlier quoted context omitted.

One thing about Veritasium is that they do get things wrong. They did one on electric circuits where if you had a circuit that was miles long with the energy source sitting right next to you, you would get current as soon as you turned on the electrical circuit because 'electricity doesnt follow the wire' or something along those lines. This has been disproven by people doing experiments

One could quibble over the details of the experiment, such as what sort of lamp to use, but Maxwell's laws would have to be repealed for the experiment to not work essentially as Veritasium claimed. Check out "electromagnetic induction" and "displacement current".

The problem is that he frames the whole whole experiment as if the inductive current is a property of the circuit rather than a property of two separate wires being next to each other - he heavily implies the inductance is result of the current "starting" to travel through the loop, and IIRC never once uses the term "inductance" (which seems odd for a video purporting to promote understanding rather than just be clickbait).

(The fact that the loop is closed can't be relevant by simple thought experiment, because otherwise it implies you could get ftl signaling by having a switch on the physically distant checking whether the "tiny current" flows when you close the source)

Re: We're building computers wrong [video]

#56

Post by phendrenad2 »

Brian_K_White wrote: post #8
l33t2328 wrote: post #5

Earlier quoted context omitted.

Something about Veritasium absolutely rubs me the wrong way, and I generally like Youtube education creators, but his videos are borderline unwatchable for me. Does anyone have an explanation for what it is about his videos that is so grating?

I don't know how to articulate it either. It's some form of uncanny valley type of thing where every detail or facet or property I might point out, there are other people exhibiting the same nominal qualities without bothering me. But something here is just slightly off in some way, but so subtly you can't say what it is. I honestly can't say he's doing anything actually wrong. I don't think even the most dumbed down…

To me the videos feel like a sustained form of clickbait. I keep expecting a payoff at the end of the video, but instead he sort of weaves together a grand narrative that nevertheless feel unfulfilling to my analytical mind. Take this video for instance. In the beginning he talks about analog computers and how they differ from digital computers. Then he talks about how neural networks work. Then he explains how neural networks could be better if they used analog values. But he doesn't ever get around to proving the title of the video ("we're building computers wrong"). He doesn't even convincingly show that we could build an analog neural network given current technology. His video format is just a lofty premise, a middle full of glossed-over science, and a disappointing conclusion with no hard takeaways.

Re: We're building computers wrong [video]

#57

Post by rapjr9 »

Check out the work of Kofi Odame on implementing algorithms in analog circuitry on integrated circuits:

https://engineering.dartmouth.edu/community/faculty/kofi-oda...

He's interested in creating analog circuits that are more efficient than digital ones for signal processing and machine learning.

I've programmed an analog computer when I was working in the military-industrial complex long ago, implemented a standard missile guidance algorithm for an IR missile using a dual feedback loop and adjustable nav ratio. It was kind of like programming with wires to implement math. It had noise limitations on accuracy, in part because of the many wires exposed to florescent lights and digital computers in the room. Quite interesting. I think the Analog Thing might make a good EuroRack music making module! Turn math into music.

Re: We're building computers wrong [video]

#58

Post by autokad »

etskinner wrote: post #39
autokad wrote: post #38

Earlier quoted context omitted.

One thing about Veritasium is that they do get things wrong. They did one on electric circuits where if you had a circuit that was miles long with the energy source sitting right next to you, you would get current as soon as you turned on the electrical circuit because 'electricity doesnt follow the wire' or something along those lines. This has been disproven by people doing experiments

Can you share the experiments that disprove it? The one video I saw proved it. Someone set up some long wires over a farm field, and measured the time to first current flow, which was faster than if the current had to travel the whole wire length. Granted, the full current flow doesn't appear until later, but the first little bit of current is there, which is exactly what Derek said in the Veritasium video

I believe this is the same video, the author theorized (probably correctly) that it was because there was residual 'power' on the wire, as it acts like a giant capacitor, among other things. this is because the wire that immediately showed up was extremely small and dissipated very quickly. https://www.youtube.com/watch?v=2Vrhk5OjBP8

Re: We're building computers wrong [video]

#59

Post by R0b0t1 »

periheli0n wrote: post #50

Yes, analog computing can be more efficient and faster. But there are reasons why analog was eclipsed by digital. 1. Flexibility. Reprogramming digital computation is easy and quick. 2. Robustness. One can mass-produce devices that operate in the digital domain and sell them as working as spec'd. But operate them in the analog domain, and you will work with a million snowflakes that all operate slightly differently,…

He touches on this in his first video. The workaround is we are now getting into a regime of computing where exact reproducibility is not necessary.

It will take a while though. It is still quite hard to remove noise for opamp circuits.

Re: We're building computers wrong [video]

#60

Post by olliej »

I liked some of veritasium's older stuff but it seems to be getting more and more clickbait as time goes on (which is reasonable as it's clear that YT is his job, and YT promotes clickbait above everything else).

A few people said that they "knew" it would be veritasium, but I had guessed it would be Mill computer folk :D

Post reply on HN