5 ms·

I haven't read much on physics before. My favourite thing to do on these stack overflow sites (or on specific tags) is to go to Questions -> sort by score, and

I haven't read much on physics before. My favourite thing to do on these stack overflow sites (or on specific tags) is to go to Questions -> sort by score, and just read through the top questions and answers. It's a bit hidden away because they want to steer people to the active questions, not to established ones.

voynich 3y ago
I always find this a more entertaining way to learn about these topics, because they're questions which we might have had before, but never thought much about.
dylan604 3y ago
Yeah, these kinds of things are what the internet should be all about rather than whatever the hell it morphed into. Sure, I'm applying my morals and expectations to it, but I don't think I've ventured onto a thin limb here.
kzrdude 3y ago
I'll just make a note of a few good ones.. https://physics.stackexchange.com/questions/121830/does-earth-really-have-two-high-tide-bulges-on-opposite-sides https://physics.stackexchange.com/questions/121830/does-eart... There is no tidal bulge
- Jun8 3y ago
  The tidal bulge one is one my all time favorites, you should absolutely read the answer. tl;dr the simplistic view of two tidal bulges (that started with Newton) is wrong! This is one of those physics simplifications that still gets pushed around. For another example, see speed of light in glass is slower than vacuum.
  - red75prime 3y ago
    > For another example, see speed of light in glass is slower than vacuum. For all practical purposes it's true. You'll get higher delays in fiber optics than in, say, radio-relay links. The details of matter-photon interaction are interesting, of course.
  - bcbrown 3y ago
    > For another example, see speed of light in glass is slower than vacuum. I'd love for you to explain what you mean by this. Either you're mistaken or I'm about to learn something really interesting. Here's a link a quick search brought me, for reference. Are you talking about something other than refractive index, ratios of c, and prisms? Like a latency metric of some kind? I'm very curious. https://en.wikipedia.org/wiki/Speed_of_light#:~:text=For%20example%2C%20for%20visible%20light,%2Fs)%20slower%20than%20c https://en.wikipedia.org/wiki/Speed_of_light#:~:text=For%20e....
    - red75prime 3y ago
      It's probably that photons always propagate at c and that the apparent change of speed of light in glass is caused by photon absorption and delayed reemission by atoms (at least it's how perturbation theory of quantum electrodynamics describes the process).
      - eternauta3k 3y ago
        Do you really need photons and quantum stuff though? "Just" learn about how dielectric materials work + how EM waves work from Griffiths and then everything will make sense.
        red75prime 3y ago
        Depends on what you want. A useful approximation, or the latest approximation that is closer to how it really is.
        eternauta3k 3y ago
        What insight is being gained by going with the more complex model? You can work out a lot using classical EM and predict a bunch of cool optical/diffraction phenomena without a lot of math, and the math you do is crystal clear. QFT or even just QM+time-dependent perturbations are a pain in the ass in comparison.
  - rocqua 3y ago
    As a note: the tidal bulge image gives an 'equipotential'. I.e. the water level you would get in equilibrium. That part of tidal bulges is right. The part that is wrong is that the actual water level is nowhere near equilibrium, because the moon moves. In fact, the water level doesn't even approximate this equilibrium but can (and does!) behave very differently.
- belter 3y ago
  GPT-4 get's this wrong...There is still hope for humans...
  - robocat 3y ago
    At least lay the blame correctly: humans get this wrong and they write it all over the internet and we then train our models on incorrect information. An astonishing amount of what we each believe is plain wrong, especially when we have little stories about it.
    - hackernewds 3y ago
      which means GPT will never be smarter than humans? same conclusion
      - axutio 3y ago
        No, but instead means that GPT can't be smarter than the people who are writing the published content on the web (generally, the very smartest humans if you're considering high quality published works alone). If you could do a perfect job of training a GPT on the entirety of published academic literature, the total of what that GPT could spit out would be limited by the knowledge contained in academic literature. At the same time, you'd have created a tool that is cheap and does a good job of synthesizing knowledge/answering questions across all disciplines. The model will never replace the scientists who are working at the very bounds of their fields, but it doesn't have to in order to be extremely useful, even useful enough to replace a majority of knowledge workers. Just because GPTs can't be smarter than the smartest humans doesn't mean they can't be smarter than most humans.
        rocqua 3y ago
        Whilst that is probably true, it is not necessarily true. Nothing fundamentally prevents GPT from synthesizing new and novel insights. If a novel insight is trivial to notice when combining knowledge from 4 disciplines, it could be neigh impossible for humans to find, and obvious to GPT. Or perhaps the insight isn't trivial but follows analagous reasoning from some other obscure result. Or perhaps a million other things. I don't mean to claim GPT will do this. I just mean to point out it can't be fully excluded GPT is able to.
mparnisari 3y ago
> they want to steer people to the active questions why?
- BenjiWiebe 3y ago
  To get answers where answers are needed.

voynich 3y ago

I always find this a more entertaining way to learn about these topics, because they're questions which we might have had before, but never thought much about.

dylan604 3y ago

Yeah, these kinds of things are what the internet should be all about rather than whatever the hell it morphed into. Sure, I'm applying my morals and expectations to it, but I don't think I've ventured onto a thin limb here.

kzrdude 3y ago

I'll just make a note of a few good ones.. https://physics.stackexchange.com/questions/121830/does-earth-really-have-two-high-tide-bulges-on-opposite-sides https://physics.stackexchange.com/questions/121830/does-eart... There is no tidal bulge

Jun8 3y ago
The tidal bulge one is one my all time favorites, you should absolutely read the answer. tl;dr the simplistic view of two tidal bulges (that started with Newton) is wrong! This is one of those physics simplifications that still gets pushed around. For another example, see speed of light in glass is slower than vacuum.
- red75prime 3y ago
  > For another example, see speed of light in glass is slower than vacuum. For all practical purposes it's true. You'll get higher delays in fiber optics than in, say, radio-relay links. The details of matter-photon interaction are interesting, of course.
- bcbrown 3y ago
  > For another example, see speed of light in glass is slower than vacuum. I'd love for you to explain what you mean by this. Either you're mistaken or I'm about to learn something really interesting. Here's a link a quick search brought me, for reference. Are you talking about something other than refractive index, ratios of c, and prisms? Like a latency metric of some kind? I'm very curious. https://en.wikipedia.org/wiki/Speed_of_light#:~:text=For%20example%2C%20for%20visible%20light,%2Fs)%20slower%20than%20c https://en.wikipedia.org/wiki/Speed_of_light#:~:text=For%20e....
  - red75prime 3y ago
    It's probably that photons always propagate at c and that the apparent change of speed of light in glass is caused by photon absorption and delayed reemission by atoms (at least it's how perturbation theory of quantum electrodynamics describes the process).
    - eternauta3k 3y ago
      Do you really need photons and quantum stuff though? "Just" learn about how dielectric materials work + how EM waves work from Griffiths and then everything will make sense.
      - red75prime 3y ago
        Depends on what you want. A useful approximation, or the latest approximation that is closer to how it really is.
        eternauta3k 3y ago
        What insight is being gained by going with the more complex model? You can work out a lot using classical EM and predict a bunch of cool optical/diffraction phenomena without a lot of math, and the math you do is crystal clear. QFT or even just QM+time-dependent perturbations are a pain in the ass in comparison.
- rocqua 3y ago
  As a note: the tidal bulge image gives an 'equipotential'. I.e. the water level you would get in equilibrium. That part of tidal bulges is right. The part that is wrong is that the actual water level is nowhere near equilibrium, because the moon moves. In fact, the water level doesn't even approximate this equilibrium but can (and does!) behave very differently.
belter 3y ago
GPT-4 get's this wrong...There is still hope for humans...
- robocat 3y ago
  At least lay the blame correctly: humans get this wrong and they write it all over the internet and we then train our models on incorrect information. An astonishing amount of what we each believe is plain wrong, especially when we have little stories about it.
  - hackernewds 3y ago
    which means GPT will never be smarter than humans? same conclusion
    - axutio 3y ago
      No, but instead means that GPT can't be smarter than the people who are writing the published content on the web (generally, the very smartest humans if you're considering high quality published works alone). If you could do a perfect job of training a GPT on the entirety of published academic literature, the total of what that GPT could spit out would be limited by the knowledge contained in academic literature. At the same time, you'd have created a tool that is cheap and does a good job of synthesizing knowledge/answering questions across all disciplines. The model will never replace the scientists who are working at the very bounds of their fields, but it doesn't have to in order to be extremely useful, even useful enough to replace a majority of knowledge workers. Just because GPTs can't be smarter than the smartest humans doesn't mean they can't be smarter than most humans.
      - rocqua 3y ago
        Whilst that is probably true, it is not necessarily true. Nothing fundamentally prevents GPT from synthesizing new and novel insights. If a novel insight is trivial to notice when combining knowledge from 4 disciplines, it could be neigh impossible for humans to find, and obvious to GPT. Or perhaps the insight isn't trivial but follows analagous reasoning from some other obscure result. Or perhaps a million other things. I don't mean to claim GPT will do this. I just mean to point out it can't be fully excluded GPT is able to.

mparnisari 3y ago

> they want to steer people to the active questions why?

BenjiWiebe 3y ago
To get answers where answers are needed.