Apparently the LED is on the order of 500 nm. Isn’t that essentially the same size as the actual wavelengths? (Just skimmed the article maybe this is discussed)
The light is produced by electrons combining with holes, so the size of the material doesn't come into it (unlike an antenna). I've personally pushed* a single rubidium atom about in a quantum computer and watched it move by emitted light (rubidium atom: ~0.25nm, emitted light 420nm depending on excitation).
* Ok, actually pressed buttons that manipulated the electric field that was trapping the atom and watched the result on a display - lot of physics going on behind the scenes.
Something akin to reciprocity still applies, no? You have a tiny rubidium atom, way too small to couple particularly strongly to the electromagnetic field at visible wavelengths. So it has a low cross-section for absorbing visible light. Won’t it necessarily radiate rather slowly as a result?
I would expect this to be somewhat of a problem with tiny LEDs. In an LED, you inject electrons and holes and you hope that a magical quantum process happens in which an electron and a hole meet, annihilate each other, and emit a photon. But this process is slow, and the electrons and the holes may wander around for a bit before combining. But in a very very small LED, smaller than the mean free path, I’d imagine you might have an issue where the electrons and holes frequently make it all the way across the device without recombining and manage to lose their energy as heat when they hit the opposite electrode. (I have not drawn the diagrams or checked the math here.)
(I took the relevant classes in grad school, but I’ve never done this sort of work academically or professionally, so no promises that I’m right.)
"Something akin to reciprocity still applies, no?"
Not necessarily. Chiral gold nanocrystals can be as small as 10nm and still be excited by 808nm laser light causing two-photon absorption and emitting in the visible range.
There is some kind of reciprocity, e.g. when an atom absorbs light and it passes into a higher energy level, it will spontaneously emit light going back to the initial energy level, with about the same probability with which it has absorbed the light.
However this reciprocity is frequently circumvented, because atoms and ions have a lot of energy levels. Instead of re-emitting the light, the atom may pass more quickly to another energy level, and from there it may emit light with a very different probability (and of a different frequency, i.e. this is fluorescence).
While in fluorescence light with a lower frequency is emitted, there is also the opposite case. In very intense light, e.g. from lasers, multi-photon absorption may happen. In that case there is also no reciprocity, because the atom has jumped an energy difference higher than that of the incoming photons. So it may re-emit light with a higher frequency.
With rubidium atoms, multi-photon absorption is very frequently used, for Doppler-effect-free spectroscopy (by absorbing photons that come from opposite directions, so that the effects of the movement of the atom will cancel). In comparison with other atoms, rubidium vapor cells are easy to procure, for spectroscopy experiments, or for use in frequency or wavelength standards, but they still are rather expensive, especially when enriched in only one of the two rubidium isotopes (e.g. if you want just rubidium 87, instead of natural rubidium, a Rb vapor cell may cost close to $1200).
Depends on the definition of slowly - thousands of photons per second upwards (and detectors are so sensitive these days that makes seeing easy). Lots of articles about on the subject, given the potential uses of this system.
It's probably more impressive that the LED was manufactured with light photons. I know it's "normal lithography" problems, but making a 500nm device out of 300nm or 400nm waves of light is downright impressive.
When it comes to solid-state photon emissions, minimum emitted wavelength is not necessarily constrained to size of the structure, but rather the electrical bandgap that needs to be overcome. Electrons are much smaller than any photon, by about 2-3 orders of magnitude, yet it is their being trapped in quantum wells which creates light emissions with wavelengths many times their size.
> ChatGPT is saying they will mark ads as ads and keep answers "independent," but that is not measurable. So we'll see.
Yeah I remember when Google used to be like this. Then today I tried to go to 39dollarglasses.com and accidentally went to the top search result which was actually an ad for some other company. Arrrg.
Before Google, web search was a toxic stew of conflicts of interest. It was impossible to tell if search results were paid ads or the best possible results for your query.
Google changed all that, and put a clear wall between organic results and ads. They consciously structured the company like a newspaper, to prevent the information side from being polluted and distorted by the money-making side.
Here's a snip from their IPO letter [0]:
Google users trust our systems to help them with important decisions: medical, financial and many others. Our search results are the best we know how to produce. They are unbiased and objective, and we do not accept payment for them or for inclusion or more frequent updating. We also display advertising, which we work hard to make relevant, and we label it clearly. This is similar to a well-run newspaper, where the advertisements are clear and the articles are not influenced by the advertisers’ payments. We believe it is important for everyone to have access to the best information and research, not only to the information people pay for you to see.
Anthropic's statement reads the same way, and it's refreshing to see them prioritize long-term values like trust over short-term monetization.
It's hard to put a dollar value on trust, but even when they fall short of their ideals, it's still a big differentiator from competitors like Microsoft, Meta and OpenAI.
I'd bet that a large portion of Google's enterprise value today can be traced to that trust differential with their competitors, and I wouldn't be surprised to see a similar outcome for Anthropic.
I agree. Having watched Google shift from its younger idealistic values to its current corrupted state, I can't help but be cynical about Anthropic's long-term trajectory.
But if nothing else, I can appreciate Anthropic's current values, and hope they will last as long as possible...
Nice! I've been using Claude Code and ChatGPT for something similar. My inspiration is Adler's concept of The Great Conversation and Adler's Propædia. I've been able to jump between books to read about the same concept from different author's perspectives.
They are identical in the same way that my Hacker News and Facebook are identical. They are both places where people post stuff and comment on stuff but the community in each is very different.
If Hacker News were to shut down for just the US users and people were told to go continue the conversation on Facebook do you think that it would feel the same?
Part of what makes TikTok and Hacker News great is the interaction with people all over the world. What's going to happen to the diaspora? Are they going to all end up in one place?
Again, if Hacker News kicked out all of the Americans living on US soil then would the rest of the users follow the Americans onto Facebook to continue the conversation?
100%. I used to love meetups in sf via meetup back in the day, really genuine people wanting to learn new things at the time. When that platform collapsed, it basically wasn’t replaced at all.
Same thing could be said of the academic side of Twitter. It’s now fragmented across Twitter, Bluesky, mastodon, and the level is discussion is very diminished
It depends on what content you watch on TikTok. Many comedy content creators on TikTok have identical, mirrored copies of their content on Instagram (an example is Leenda Dong, who has been very popular on both TikTok and Instagram).
This was also tested in practice in India, when the country banned TikTok in 2020. Rest of World published a report in 2023 with the conclusion that most users simply switched to Instagram Reels or YouTube Shorts without much complaint, just as the previous commenter predicted: https://restofworld.org/2023/america-india-tiktok-ban/
That's similar to the idea I had for combating texting spam:
- If your number is in my address book then texts are free for you
- If this is the first time you are contacting me then you pay me $1
There are probably downsides and ways this will screw up real relationships but it will certainly increase the cost of spam.
- Every contractor (plumber etc) you hire will ask you to please add them to your contact list first so that they can message you.
- After a while of half their clients not doing that and lots of fees on their end, contractors stop providing a phone number at all, asking you to please install ContractorApp to communicate with them.
I love every part of this. Not having things in writing is one of the most common tactics with bad contractors. And I miss their call backs because I have unknowns goto spam, so I have to remember to disable that feature...
Ha! Okay, I like this, I think it changes my mind on the whole thing being viable. There's probably some reason it wouldn't work in reality but the satisfaction from pressing the charge $1 option on spam would be huge.
I disagree about the we-adda-baby-itsa-boy issue. I don't see how that'd apply given that you can charge them $1 from the very first message.
The most amazing sky I’ve ever seen was when I arrived in Urubichá in Guarayos region of Bolivia in 1998 before the electricity arrived in the area. I traveled by bus to visit my friend’s childhood home. The bus only went to the big city an hour away so I road in the back of a jeep the rest of the way, at night. I remember vividly not understanding what this super-bright light was in the sky. I know now it was either Venus or Jupiter, but it looked artificial because it was so much brighter than I was used to seeing.
Venus is known as either the ‘morning star’ or ‘evening star’ depending on where Venus is in its orbit relative to Earth.
It actually just recently (start of June) went behind the sun; it’s still too close to the sun in the sky to really be visible at all at the moment. As it moves further out from behind the sun it will start being visible in the evening sky in late July right after the sun sets, so it will be the ‘evening star’ again for the next eight months or so before it passes in front of the sun, disappearing from view for a bit, then comes back as the morning star next summer.
