[HN Gopher] Atomic resolution video of salt crystals forming in ...
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       Atomic resolution video of salt crystals forming in real time
        
       Author : neltnerb
       Score  : 101 points
       Date   : 2021-10-07 12:56 UTC (10 hours ago)
        
 (HTM) web link (phys.org)
 (TXT) w3m dump (phys.org)
        
       | johtso wrote:
       | This reminds me of my first time using a microscope. I was on a
       | course on mushroom identification and we were looking at spores
       | and other microscopic features.
       | 
       | I was so surprised when I saw shapes in the viewfinder that
       | didn't look organic. There were squares and pyramids, it looked
       | like Aztec ruins. And they were growing before my eyes! I then
       | realised it was the reagents crystallising in the heat of the
       | lamp.
       | 
       | The world of microscopes is like magic, it's a shame that more
       | people aren't exposed to it.
       | 
       | Even just a quality 10x hand lens opens up a whole world of
       | detail that we don't usually see.
        
         | hellbannedguy wrote:
         | Good used microscopes are so cheap now. If I had a child, it
         | would be on their desk early, like kindergarden.
        
           | xattt wrote:
           | Any suggestions for models to be on the look out for? I
           | bought some generic plastic $45 CAD kit that's good enough,
           | but would love to have an idea of what to focus on next.
        
             | yummypaint wrote:
             | Check out the foldscope
        
             | beecafe wrote:
             | If you want something a bit DIY but very capable, check out
             | the openFlexure scope. It's a 3d printed body to which you
             | can add an objective and it has a 3d printable
             | micropositioning stage and Pi camera mount.
        
       | endisneigh wrote:
       | at what point does the observing affect the observation?
        
         | dotancohen wrote:
         | When she shuts the blinds and calls the cops.
        
           | twodai wrote:
           | This is lewd but funny, I needed that laugh.
        
         | sparsely wrote:
         | I think in this case the surface interaction effects with the
         | nanotube are likely to be much bigger
        
       | amelius wrote:
       | How could they tell from the video which atoms were Na and which
       | were Cl?
        
       | G3rn0ti wrote:
       | While we don't have flying cars, watching single sodium and
       | chloride ions forming crystals in 25 FPS surely makes me feel
       | like living in the future, finally.
        
       | cromwellian wrote:
       | Atomic resolution real-time video at 25 frames per second!!! Holy
       | cow! I mean, the nanohorns and salt crystal study is cool and
       | all, but the real time video!? That's mind blowing, the kind of
       | stuff we saw on Star Trek: The Next Generation.
        
       | miduil wrote:
       | Previous discussion:
       | 
       | > Atomic resolution video of salt crystals forming in real time
       | (u-tokyo.ac.jp)
       | 
       | > 664 points by rbanffy 8 months ago | 125 comments
       | 
       | https://news.ycombinator.com/item?id=25874497
        
       | gavinray wrote:
       | "growing"
       | 
       | Expected video to show process of atoms slowly forming together
       | or something to shape my mental model.
       | 
       | What I got was a full-formed grid of little atom things that just
       | seemed to spring into existence between two frames.
       | 
       | It's still cool. But I am not less confused.
        
         | danparsonson wrote:
         | From the article it seems like the 'springing into existence'
         | is a process called nucleation:
         | https://en.wikipedia.org/wiki/Nucleation.
        
         | steerablesafe wrote:
         | My guess is that individual atoms entering and leaving the
         | formation happens on a much faster timescale than the formation
         | switching between quasi-stable states.
         | 
         | It's almost as-if there are mini phase-transitions between
         | formation sizes, it's fascinating.
        
         | crispyambulance wrote:
         | Both modes are possible, if I read it correctly (see the bottom
         | half of the first figure). Pieces of the lattice can "spring"
         | into existence very quickly-- that's a phase transition. But,
         | once formed, it can also "grow" atom by atom.
        
         | lmilcin wrote:
         | 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.
        
           | omnicognate wrote:
           | The video is at atomic resolution. The dots in the
           | crystalline structure are individual atoms.
           | 
           | To do this in _realtime video_ is bonkers.
        
             | lmilcin wrote:
             | 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.
        
               | omnicognate wrote:
               | 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).
        
             | s1artibartfast wrote:
             | This much is clear. The post above answers the question of
             | why we can't see atoms that are not part of the lattice.
        
         | ASalazarMX wrote:
         | The grid appears suddenly, but strips of atoms keep piling on
         | like those magnet ball toys, and it looks like it grows too big
         | for its containment.
         | 
         | Maybe it grows slower as it gains more surface?
        
       | sp332 wrote:
       | I know it's just from this year, but January feels like a long
       | time ago.
        
       | everyone wrote:
       | Is there a link to just the video anywhere?
        
         | luegen wrote:
         | https://scx2.b-cdn.net/gfx/video/2021/crystalclose.mp4
        
         | 4wsn wrote:
         | https://scx2.b-cdn.net/gfx/video/2021/crystalclose.mp4
        
       | arthurcolle wrote:
       | I believe this is from last year, I remember those little squares
       | from a past life.
       | 
       | EDIT: January 12, 2021 - looks like my brain isn't fully swiss
       | cheesed yet after all
        
       | tryauuum wrote:
       | Looks so neat. I hope people from SaltStack will see this
        
       | singularity2001 wrote:
       | 20 seconds? I thought molecules speed through a thousand cells in
       | a fraction of a second!? How come the formation of salt in this
       | setting is so (relatively) exorbitantly slow?
        
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       (page generated 2021-10-07 23:02 UTC)