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It was almost impossible to make the blue LED [video]

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Re: It was almost impossible to make the blue LED [video]

#191

Post by fernmyth »

pavel_lishin wrote: post #186
bseidensticker wrote: post #81

Earlier quoted context omitted.

The blue is nicer if you do that. Technology Connections has made 3 videos over the last 5 years mostly centering around how he hates the blue led lights used in holiday lights. I think I've only seen the 2 yr old one, but now that I have I can't unsee it. The blue is just too blue. If you see a set that is all blue instead of multi-color it's unbearable. It's just too blue. White light in blue plastic is where it's…

Something odd about that ultra-blue color - when I'm outside at night, I can see any lit up sign in relatively good focus with my glasses on. Green signs, red signs, etc. But anything blue always looks blurry unless I'm very close to it.

The lenses in your eyes refract different wavelengths at different angles - think of a rainbow coming out of a prism. Only one wavelength can be perfectly tuned to project a clear image onto your retinas. We are optimized for green, red is close enough, but blue always looks blurry.

Re: It was almost impossible to make the blue LED [video]

#193

Post by diedyesterday »

cypherpunks01 wrote: post #48

I thought this was a really well-produced video! It's difficult to communicate science to the public in an accessible way at the right level, and I think Derek does a commendable job. I really liked the LED explanation at the 4:00 mark. Can anyone who is familiar with semiconductor physics opine on how well this explanation models the reality?

That explanation closely follows the outline of the equally good and very accessible explanation offered in the Halliday/Resnick/Walker's Fundamental's physics (11 edition, chap. 41)

Re: It was almost impossible to make the blue LED [video]

#194

Post by pavel_lishin »

fernmyth wrote: post #191
pavel_lishin wrote: post #186

Earlier quoted context omitted.

Something odd about that ultra-blue color - when I'm outside at night, I can see any lit up sign in relatively good focus with my glasses on. Green signs, red signs, etc. But anything blue always looks blurry unless I'm very close to it.

The lenses in your eyes refract different wavelengths at different angles - think of a rainbow coming out of a prism. Only one wavelength can be perfectly tuned to project a clear image onto your retinas. We are optimized for green, red is close enough, but blue always looks blurry.

Huh, I like that theory. Nobody else has ever mentioned experiencing the same thing as I do, though.

Re: It was almost impossible to make the blue LED [video]

#197

Post by jbboehr »

etiam wrote: post #155
jacobolus wrote: post #114

Earlier quoted context omitted.

LED lighting in practice is typically terrible (though not always or inevitably): the spectrum is too blue and too spiky, without due respect for human needs. It has ruined nighttime lighting, especially outdoors in applications like street lamps, car headlamps, camp lamps, and flashlights. Whatever marketing people are making decisions in the lighting industry have insufficient understanding of human color vision an…

Agreed on all. I'd like to add it also pains me that the power to produce about five times more light for the same electricity expenditure has been given without question or qualification to most of humankind, and yet almost no-one seems to ask themselves whether keeping spending the same energy and producing about five times as much light is what they should be doing...

See also: https://en.wikipedia.org/wiki/Jevons_paradox

Re: It was almost impossible to make the blue LED [video]

#198

Post by etiam »

jbboehr wrote: post #197
etiam wrote: post #155

Earlier quoted context omitted.

Agreed on all. I'd like to add it also pains me that the power to produce about five times more light for the same electricity expenditure has been given without question or qualification to most of humankind, and yet almost no-one seems to ask themselves whether keeping spending the same energy and producing about five times as much light is what they should be doing...

See also: https://en.wikipedia.org/wiki/Jevons_paradox

Yes, the thought has occurred to me. This one seems particularly egregious, since it often results in going from a reasonable quantities of decent quality light to noxious quantities of noxious quality light.

Re: It was almost impossible to make the blue LED [video]

#200

Post by pxmpxm »

dang wrote: post #175
Draiken wrote: post #138

Earlier quoted context omitted.

I don't understand. This is literally part of what the video talks about: how he got fired after giving them billions. How is this an ideological battle? It's what was described in the video. I don't disagree that I talk about capitalism on some threads that aren't specifically mentioning it, but in this case it's 100% part of the content. I can only hope that the same treatment happens for accounts with the opposite…

I believe you that there was a point of contact with the article but the problem is that your comment went on a generic ideological tangent from it, straight into regular flamewar territory, which is what we're trying to avoid. The more important point, though, is the pattern of posting like this. An isolated case isn't a problem but if it becomes a pattern, that's different; that's not the intended use of this site.…

People see what they wanna see, especially if their hobby is to promote empirically-failed worldviews.

EG Moonshot research grant of $3 million / 15% of company's revenue is somehow capital exploiting labor, or whatever such superficial Das Kapital take, and no cognitive dissonance that inventions of this sort somehow didn't materialize in DDR or SSSR.

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