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A comment on Atomic resolution video of salt crystals forming in real time. Parent comment

Re:Atomic resolution video of salt crystals forming in real ... by lmilcin on Thursday October 07, 2021 @10:19AM (#28786585)
The individual atoms are much more mobile than the crystalline structure here. They are probably moving way too fast to be captured on a time scale that the crystal grows.

Think in terms of trying to make video of a tree growing and expecting to see individual water droplets falling from the sky.

You can infer the droplets must be there (as the ground would otherwise dry out and the tree die) but it is not possible to have a video of tree growing sped up so that a human can see it growing but also show water droplets falling from the sky.

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Re:Atomic resolution video of salt crystals forming in real ... by omnicognate on Thursday October 07, 2021 @12:38PM (#28788706)
The video is at atomic resolution. The dots in the crystalline structure are individual atoms.

To do this in realtime video is bonkers.

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Re:Atomic resolution video of salt crystals forming in real ... by lmilcin on Thursday October 07, 2021 @01:16PM (#28789340)
It is bonkers. But the only way we can even have that video is because the molecules are being frozen in the crystalline lattice.

As far as I know there exists no recording of actual molecules in a liquid (except maybe for something extremely viscous).

The video reminds me this photo: https://petapixel.com/2010/10/27/first-ever-photograph-of-a-...

It shows first ever photo of a human being on a busy street.

But you would not be able to say so, because the street looks completely empty.

The only way we can even see the person is because they stood still for long enough to leave imprint. Other than this one person, everybody else on this busy street moved so fast there is no recognizable imprint of them left. Hence the street looks empty.

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Re:Atomic resolution video of salt crystals forming in real ... by omnicognate on Thursday October 07, 2021 @04:55PM (#28791933)
Gotcha, I misunderstood - thought you were referring to the scale of the raindrops relative to the tree, not the speed. The photo's a better analogy (and cool).
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Re:Atomic resolution video of salt crystals forming in real ... by s1artibartfast on Thursday October 07, 2021 @01:19PM (#28789399)
This much is clear. The post above answers the question of why we can't see atoms that are not part of the lattice.
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