19 ms·

Truly mind blowing being able to actually see the atoms align in an instant and the crystal structure just pop into existence. Hard to believe it’s not a compu

by zaroth 6y ago

Truly mind blowing being able to actually see the atoms align in an instant and the crystal structure just pop into existence. Hard to believe it’s not a computer model. I mean, I guess underneath there must be a hell of a lot of signal processing going on to render that video, but atomic-scale video is wild. Funny that it looks kinda like MPEGS online circa 1990s.

mywittyname 6y ago
I also love how you can see the probabilistic nature of electron orbitals in action. The crystal fades in and out of existence during the early stages of nucleation. And even after the structure is established, the boundaries continue to be "fuzzy." Even the movement of the crystal looks like a wave, but I don't know if that's because matter moves as a wave at the atomic level or if that's just an artifact from the camera.
- Osmium 6y ago
  > I don't know if that's because matter moves as a wave at the atomic level or if that's just an artifact from the camera. Artifact of the imaging, note the time scale of the movie, it's much longer than any quantum oscillation. Each individual image of the movie is taken eons apart from the perspective of the crystal.
  - magicalhippo 6y ago
    > Each individual image of the movie is taken eons apart from the perspective of the crystal. Given the timescales of atomic reactions, which IIRC is typically measured in nano- or picoseconds, this video is more like watching galaxies form I suppose.
- jng 6y ago
  I would think that the coming in and out of view at the beginning is more related to the crystal moving around and falling "in and out of focus" (whatever that means for this type of camera). I'd love to watch quantum probability wave fluctuations, but I think we're still pretty far from probing that.
  - jtaillon 6y ago
    In this case, "in and out of focus" is actually variations in the amplitude of the probability function for the electron density projected onto a single plane (to a first approximation). Sometimes the wave functions of all the electrons interfere constructively, so you see a bright spot, and sometimes deconstructively, so you see dark. Depending on the orientation of things, this results in the images of "atoms" that you see in the picture. As the crystal changes shape and size, the interference patterns change, which partially explains why it disappears and reappears a few times. There's a bit more going on than that, but the physics of what's happening in a TEM image is really neat.
    - jng 6y ago
      Wow, mind blown. Thanks for correcting me. Amazing to learn that the wave function is so directly sampled by TEM that the image we get shows Moiré patterns caused by its phase :)
    - Ericson2314 6y ago
      Per the other comments, I think time scale is far to large for that to be the case in any not-also-explained-classically sense.
    - gus_massa 6y ago
      Most of the electrons in a NaCl crystal are quite localized (all the core electrons od Na+ and Cl-, and it's not a good conductor, so the valence band is full). So I don't expect too much interesting interference patterns. It looks like a problem with vibrations that make it go out of focus.
- WClayFerguson 6y ago
  It's almost like a "standing wave" (of the square pattern) emerged spontaneously out of a chaotic stew of probability waves, and I guess that's a better way to describe quantum mechanics at this level than to say "The Na and Cl atoms snapped together". Nothing snapped to together. This video shows a pattern emerging from pure chaos, all based on probabilities and the fact that each individual atom probability wave can only oscillate in certain patterns. I'm pretty sure in Quantum Mechanics systems like this the entire unit behaves as one and there's no real distinction possible regarding "which is which" if you were to try to identify individual atoms. It would be like looking at a standing wave pattern in water (or any other medium) and labeling one peak "Wave A" and some peak "Wave B". You can't really do it. Because for the standing wave pattern to exist at all it has to be the entire system interaction to cause it to emerge. I'm not saying atoms are "Standing Waves" but I'm merely making an analogy. However even from some perspective you could even say any oscillating system of wave probabilities when taken as a "system" comprises a standing wave.
  - WClayFerguson 6y ago
    Not that I'm trying to blow anyone's mind but here's a couple of other 'emergent patterns' in reality which can also be called standing waves, which proves some very low level patterns like DNA can cause identical patterns to emerge billions of layers higher in the causal chain of reality, and way higher than just the physical structure of the body and brain but also into the surrounding world. https://www.reddit.com/r/BeAmazed/comments/l2mtfx/separated_at_birth/ https://www.reddit.com/r/BeAmazed/comments/l2mtfx/separated_...
  - gus_massa 6y ago
    > I'm pretty sure in Quantum Mechanics systems like this the entire unit behaves as one and there's no real distinction possible regarding "which is which" if you were to try to identify individual atoms. The grow experiment was at room temperature 298K. At this temperature the nuclei of the atoms behave almost classically. There are some important quantum effects between the electrons, but their mass is like 10000 smaller. The effects are small in the electrons in the lower levels that are close to the nuclei, but in the valence band they can be very important. Specially in conductors where the electrons are very delocalized, but this is not a conductor.
noneeeed 6y ago
I find a lot of the science being done at the moment truly astonishing, the precision and scale of many of the measurements being made are mind-blowing. The sensitivity of instruments like LIGO is hard to get your head around.
anthk 6y ago
Also, static from no TV signals on the TV.
- m463 6y ago
  self-organizing static

by zaroth 6y ago

mywittyname 6y ago

I also love how you can see the probabilistic nature of electron orbitals in action. The crystal fades in and out of existence during the early stages of nucleation. And even after the structure is established, the boundaries continue to be "fuzzy." Even the movement of the crystal looks like a wave, but I don't know if that's because matter moves as a wave at the atomic level or if that's just an artifact from the camera.

Osmium 6y ago
> I don't know if that's because matter moves as a wave at the atomic level or if that's just an artifact from the camera. Artifact of the imaging, note the time scale of the movie, it's much longer than any quantum oscillation. Each individual image of the movie is taken eons apart from the perspective of the crystal.
- magicalhippo 6y ago
  > Each individual image of the movie is taken eons apart from the perspective of the crystal. Given the timescales of atomic reactions, which IIRC is typically measured in nano- or picoseconds, this video is more like watching galaxies form I suppose.
jng 6y ago
I would think that the coming in and out of view at the beginning is more related to the crystal moving around and falling "in and out of focus" (whatever that means for this type of camera). I'd love to watch quantum probability wave fluctuations, but I think we're still pretty far from probing that.
- jtaillon 6y ago
  In this case, "in and out of focus" is actually variations in the amplitude of the probability function for the electron density projected onto a single plane (to a first approximation). Sometimes the wave functions of all the electrons interfere constructively, so you see a bright spot, and sometimes deconstructively, so you see dark. Depending on the orientation of things, this results in the images of "atoms" that you see in the picture. As the crystal changes shape and size, the interference patterns change, which partially explains why it disappears and reappears a few times. There's a bit more going on than that, but the physics of what's happening in a TEM image is really neat.
  - jng 6y ago
    Wow, mind blown. Thanks for correcting me. Amazing to learn that the wave function is so directly sampled by TEM that the image we get shows Moiré patterns caused by its phase :)
  - Ericson2314 6y ago
    Per the other comments, I think time scale is far to large for that to be the case in any not-also-explained-classically sense.
  - gus_massa 6y ago
    Most of the electrons in a NaCl crystal are quite localized (all the core electrons od Na+ and Cl-, and it's not a good conductor, so the valence band is full). So I don't expect too much interesting interference patterns. It looks like a problem with vibrations that make it go out of focus.
WClayFerguson 6y ago
It's almost like a "standing wave" (of the square pattern) emerged spontaneously out of a chaotic stew of probability waves, and I guess that's a better way to describe quantum mechanics at this level than to say "The Na and Cl atoms snapped together". Nothing snapped to together. This video shows a pattern emerging from pure chaos, all based on probabilities and the fact that each individual atom probability wave can only oscillate in certain patterns. I'm pretty sure in Quantum Mechanics systems like this the entire unit behaves as one and there's no real distinction possible regarding "which is which" if you were to try to identify individual atoms. It would be like looking at a standing wave pattern in water (or any other medium) and labeling one peak "Wave A" and some peak "Wave B". You can't really do it. Because for the standing wave pattern to exist at all it has to be the entire system interaction to cause it to emerge. I'm not saying atoms are "Standing Waves" but I'm merely making an analogy. However even from some perspective you could even say any oscillating system of wave probabilities when taken as a "system" comprises a standing wave.
- WClayFerguson 6y ago
  Not that I'm trying to blow anyone's mind but here's a couple of other 'emergent patterns' in reality which can also be called standing waves, which proves some very low level patterns like DNA can cause identical patterns to emerge billions of layers higher in the causal chain of reality, and way higher than just the physical structure of the body and brain but also into the surrounding world. https://www.reddit.com/r/BeAmazed/comments/l2mtfx/separated_at_birth/ https://www.reddit.com/r/BeAmazed/comments/l2mtfx/separated_...
- gus_massa 6y ago
  > I'm pretty sure in Quantum Mechanics systems like this the entire unit behaves as one and there's no real distinction possible regarding "which is which" if you were to try to identify individual atoms. The grow experiment was at room temperature 298K. At this temperature the nuclei of the atoms behave almost classically. There are some important quantum effects between the electrons, but their mass is like 10000 smaller. The effects are small in the electrons in the lower levels that are close to the nuclei, but in the valence band they can be very important. Specially in conductors where the electrons are very delocalized, but this is not a conductor.

noneeeed 6y ago

I find a lot of the science being done at the moment truly astonishing, the precision and scale of many of the measurements being made are mind-blowing. The sensitivity of instruments like LIGO is hard to get your head around.

anthk 6y ago

Also, static from no TV signals on the TV.

m463 6y ago
self-organizing static