Double Slit Experiment with Living Organisms

The double slit experiment is usually performed with light or electrons. But have you ever seen how living organisms behave? For this experiment the alga Volvox was used and it shows some remarkable properties.

#microbes #biology #quantumphysics

Microscopes used:
Olympus CX43
Olympus BX53

Cameras:
Sony A 6400
Fuji XT4
Canon R5

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Pictures:
Alexandre Gondran
NekoJaNekoJa

[rayduck]

OK... I was busy typing a comment to say that all you've done is used volvox to paint the light path and pattern of a standard type of double slit light experiment, but then I realised that would only be true if light was being projected from the left hand side. Since the light source is on the right (at he destination) it is astounding to see the volvox grouping in what looks like interference nodes and also accumulating at the light source in bands. Keep up the experiments, I'm sure more can be learned here.

[igobivo]

If it has to do with interference, which I think is not, it is probably due to the currents in water produced by the moving volvoxes. When passing through the slits, these currents cause waves, which then capture volvoxes.

[holyholsteins]

Interesting replication. You were thinking outside of the pond. Thank you!

[alphabetagamma]

As a physicist, I find this absolutely baffling.
I really, really want to know what causes this.
This video needs more attention from the big guys.

[vxgirxv]

Please!! Add another video introducing the other aspects of the double slit experiment invoking both 1 slit as well as 1 volvox or 1 group of volvox moving at a time.

[PerihelionPhase]

Can you show a negative before showing a positive? I.e. does this pattern not appear without the slits present? Could the light be interfering as it bounces back off the other wall of the box and through the slits? Attracting the volvox to the areas of differing intensity? Perhaps minute motions of the tray are creating waves in the water, interfering as they pass through the slits and influencing the movement of the volvox. This last possibility makes the most sense to me.

[aq_ahmed]

I feel that this experiment is amazing and deserves further scrutiny and commitment of time and resources from the world of quantum physicists. May be it holds the key to many problems in our life and the universe

[matttrophy]

I guess the question is, we’re you watching when this happened?

[tra]

There are probably a few different rules that evolved because of their utility that are overlapping that cause this.

Possible Rules Example:
1 prefer to clump
2 prefer to split off if clump is too large
3 prefer to move toward the light

Imagine rule 1 like attraction
Imagine rule 2 like repulsion
Imagine rule 3 like attraction, but slightly stronger than rule 2 but only in a specific direction

When they are moving accross an empty space, rules 1 and 2 interact to cause the clumps. There is enough open space to continue moving toward the light so they don't form lines in the direction of the light.

When they reach the wall, the rule "prefer to move toward the light" overcomes the rule 2(large clump repulsion) in the direction of the light, while rule 2 repulsion causes the splitting into channels parallel with the light rays (because rule 3 light attraction is only overcoming rule 2 repulsion toward the light and not in the perpendicular direction)

[IGroupchannel]

Wow! Let's make a Podcast about it!

[treway]

Are there any more developments on what you think is happening here? This is the only type of experiment I’ve seen and my curiosity is driving me insane now. Lol great video, would love a part 2!!

[BD-npbv]

Your light source is on the right, and the interference pattern should be on the left. There's possibly a few different issues here. What I'd suggest is this:

1. Use an acrylic container to hold the microorganisms.

2. Use a big black construction paper or even think cardboard or both to block the light source on the outside of the acrylic glass, and cut two slits very close together. This way a true double slit experiment is being done while the acrylic barrier prevents the microorganisms from going through the slits.

3. Turn off all light sources except the one for the experiment. Hopefully you have a small flashlight, or perhaps the flashlight from a phone.

The goal here is to:

1. Create a double slit experiment where in theory light waves will cancel out certain paths while construct to form "visible" light in other paths.

2. See if the microorganisms can detect these "constructed" light paths while ignoring the cancelled out paths and form lines that mimic the expected wave pattern.

There's already experiments where a straight laser light is used, which is cleaner as opposed to any regular lightbulb. However, I'm not sure if those microorganisms prefer (or can only/can't detect) white light or certain color lights.

Let us know how it goes!

[frankied.]

OH MY GOD! THIS IS INCREDIBLE! I NEED TO TRY THIS AT HOME!

[lorpis]

Flocks seem to mimic field or fluid like behaviour such as smoke or water. Maybe try placing a less intense light at the slits to disrupt the homogeneous migration and see if you get two slits instead of an interference pattern at the main wall. I would also check to see if light frequency has a measurable effect on the on the pattern. Maybe they are highlighting the field by chasing areas of highest energy density. Nice work!!! That was really interesting.

[micro_safari]

This is super interesting! Amazing how many parallels you can find in nature.

Is the right side illumination of the tray entirely homogenous? And when looking at the Volvox under the microscope, can you see and interaction between individuals or do they just bump into each other like particles?

Thank you for sharing. One of the coolest experiments I've seen.

[giorgiopattarini]

Woooo fantastic
my bet is that the wave-like behaviour of the population arise from some interaction, they like keep distance from each other but take some time to react from neighbours; like dissipative waves. So the population as a whole moves in waves with well defined wavelength. Beautiful that they're quantized colonies...

[AdityaMehendale]

Effing amazing :)
What would a good "null hypothesis" be in this case? If you had a single opening, would you get a "Gaussian" distribution instead of bands?
Are there any confounding factors? For example, is the LED-lightsource made of multiple dice that may have bright-spots?

[spaceminers]

Get a ruler out and measure the physical distance between the concentrated areas and the gaps that are formed on the wall. Take the reciprocal of the physical wave length and you will have a frequency. I’m predicting you’ll get a frequency of 60 Hz because it’s found everywhere unless you’re doing this test overseas and you should get a frequency of 50 Hz

[zamioculcaszamiifolia]

Thats so cool! You may want to try this with other motile algae to see if it's just the volvoxes that do this or not

[kipper]

Super cool, I wonder if there would be a way to replicate the wave form collapse