Videomicrography: water drops.

[Beatsy]

This is cool. Great to watch, but I can't help thinking about the how. Doesn't look that hard to set up, given the right cultures, and sparked a fair few ideas too...

https://www.youtube.com/watch?v=kfQQc4CaNAk

Edit: a "how" video by the same chap - https://www.youtube.com/watch?v=Slwkped573s - and the "accidental discovery" will REALLY get you thinking!

[Tom Jones]

Nice video, even if too many organisms are labeled Brachionus plicatilis!

I don't even know what to say about the "double-slit" experiment That's really strange!

[patta]

The double slit experiment is so beautiful, like observing green photons in slow motion!

[Lou Jost]

Wow the double slit experiment is bizarre!

[rjlittlefield]

Hhmm... I notice that he does not show a single-slit experiment, and I speculate that a single slit would show the same sort of columnar aggregation that the double-slit does.

This does not look to me like wave interference.

Instead, it looks more like the sort of aggregation into clumps that he shows when the Volvox are moving across open space en masse, around 1:10. I note especially that around 2:31-2:37, there's a lot of lateral movement of individual colonies, even movement of the column centers and spacings, yet still the overall columnar structure persists. This is all quite different from particles landing with a density that is periodic, and looking at the accumulation of landing points.

It's a very interesting question what process causes aggregation at all. Possibilities that come to mind include chemical hints, something to do with fluid dynamics around the moving colonies, and something to do with shadowing/filtering of the light that is attracting them in the first place.

Pretty much all this seems to be covered by various comments at YouTube.

Definitely thought-provoking in any case.

--Rik

[Beatsy]

Agreed Rik, it's the clumping mechanism, no quantum effect (I should have mentioned that in the original post). You can see several "bands" of volvox building up behind the lego pieces for one thing - before going through the slits.

But as you say, the aggregation itself is interesting, and why do barriers cause it to form stripes instead of blobs?

An intriguing diversion, but not quantum at all...

[Lou Jost]

No, but still really intriguing in the way that it suggests a similar mathematical description.

[MarkSturtevant]

I agree with Rik. Although the interference patterns also appear when one fires atoms or even very large molecules thru a double slit experiment ( https://www.nature.com/articles/nnano.2012.34 ) It cooks 'm noodle.

As for the hanging drop imagery, those are very cool. I think it would be fairly simple to do something 'arty' like that where you have a drop hanging from a leaf, and inside are a couple Daphnia or Tardigrades.