Light Pulse Travelling Through A Water Bottle (trillion frames per second)

[Kevin_Axion]

 

[rhody]

Kevin,

FYI. I have a thread in Fun Photos and Games that is all about high speed slow motion photography here.

Rhody...

 

[feathermoon]

Someone commented on that video:

'They should perform the double slit experiment . . ' with this setup.

It would be neat to see..

 

[rhody]

Background on the technology that created your video.

For instance for ultrasound, this can be replaced with this technology
which analyzes how light scatters volumetric-ally within the human body.



Rhody...

 

[berkeman]

Background on the technology that created your video.

For instance for ultrasound, this can be replaced with this technology
which analyzes how light scatters volumetric-ally within the human body.



Rhody...

Dang you Kevin, you had me going there for a bit.

It's a strobe system. It's the repeated nature of the signal and the repeated photo captures with slightly different delays that makes the final video.

Lordy.

 

[rhody]

Those MIT guys are if nothing else a clever lot, eh ??!

Rhody...

 

[Jimmy Snyder]

Someone commented on that video:

'They should perform the double slit experiment . . ' with this setup.

It would be neat to see..

If you observe the light going through the slits, you don't get the interference pattern.

 

[Chi Meson]

I read through some of the comments and I learned that photons are luxons, unlike other things made of bradyons, and electrons are made of quarks.

I'm dummer now.

I'm going to buy a Hummer.

 

[rootX]

I read through some of the comments and I learned that photons are luxons, unlike other things made of bradyons, and electrons are made of quarks.

I'm dummer now.

I'm going to buy a Hummer.

i'm guessing you don't even know what a luxon is.

 

[Ivan Seeking]

I think I can see a neutrino just ahead of the light pulse.

 

[Kevin_Axion]

I read through some of the comments and I learned that photons are luxons, unlike other things made of bradyons, and electrons are made of quarks.

I'm dummer now.

I'm going to buy a Hummer.

A luxon is a particle with an imaginary rest mass

A bradyon has a rest mass greater than zero

A photon is neither a luxon nor a bradyon since its rest mass is equal to zero.

Electrons are elementary particle and as are quarks, both of these are bradyons.

 

[feathermoon]

If you observe the light going through the slits, you don't get the interference pattern.

Right, but remember this is a series of 1 dimensional videos laid together. In the runs of the experiment where the video wasn't trained on a slit the wave function wouldn't collapse? I mean, does the wave collapse when you constrain the particles position slightly or fully? I guess I don't really know everything about the experiment, now that I think about it. :D

Someone is probably dummer for my comments, probably just me though.

 

[LaurieAG]

It would be neat to see..

If a photon pulse was coming through both slits would you see two photon pulses with half the intensity of the original pulse?

Any strobe based delay system like this would be expected to record and accumulate anything that had a realistic probability of occurring. The only way you would really see any measureable difference would be if you could reduce the pulse size down to a single photon. It would be difficult to do with this setup if the pulse is exciting gas that is picked up by the strobe.

If you could get down to a level where you could tell the difference between the output of even and odd numbers of photons in the pulse beam you would probably see some interesting things. With just three photons would you expect a 50:50 split or 33:66 or 66:33?

 

[Chi Meson]

i'm guessing you don't even know what a luxon is.

I have to admit I never heard of a "bradyon" before, and I thought the poster was corrupting "baryon."

Though I'm pretty sure that you won't find a quark inside an electron.

And the Hummer was a stupid idea.

Still the lesson remains: don't read comments under Youtube videos.

 

[Jimmy Snyder]

With just three photons would you expect a 50:50 split or 33:66 or 66:33?

If you observe the photons at the slits, you will see a 2:1 ratio and no interference pattern at the screen. If you don't observe the photons at the slits, you will see an interference pattern at the screen and be able to infer a 1:1 ratio from the pattern.

What feathermoon suggests is that we observe the photons at the slits and record it. Then observe the photons at the screen and record that. Then photoshop the two recordings together. I think that it would work.

 

[feathermoon]

Yea, just it being a 1 dimensional recording makes me wonder. Is there an experiment where only part of the slit is looked at? Would there be no interference pattern or a partial pattern? Does constraining a particle to a smaller area completely collapse its wave function or partially collapse it?

 

[navynuclear]

All theory aside, I just thought it was a cool video. Kinda like a photon torpedo...

 

[Jimmy Snyder]

Yea, just it being a 1 dimensional recording makes me wonder. Is there an experiment where only part of the slit is looked at? Would there be no interference pattern or a partial pattern? Does constraining a particle to a smaller area completely collapse its wave function or partially collapse it?

It's a one dimensional recording because all of a second dimension is projected onto the one dimension. I don't see how you could set it up so that only part of that second dimension was projected. What did you have in mind?

 

[LaurieAG]

If you observe the photons at the slits, you will see a 2:1 ratio and no interference pattern at the screen. If you don't observe the photons at the slits, you will see an interference pattern at the screen and be able to infer a 1:1 ratio from the pattern.

What feathermoon suggests is that we observe the photons at the slits and record it. Then observe the photons at the screen and record that. Then photoshop the two recordings together. I think that it would work.

Hi Jimmy,

In the context of the pulse and the strobe setup you would capture both before and after with different pulses and the screen itself would be unnecessary.

 

[Jimmy Snyder]

Hi Jimmy,

In the context of the pulse and the strobe setup you would capture both before and after with different pulses and the screen itself would be unnecessary.

Before and after what? Before the photons reach the slits, nothing interesting happens. If you observe them after they pass the slits, but before they reach the screen you destroy the inteference pattern. The only way I can see to make this work is to film it twice, once at the slit and once at the screen. Then combine the two sequences to make it look like they were one.

Edit: I take it back. This would not work. As soon as the photons leave the slit, the interference pattern is already broken. Having once seen the photons past the slit, the interference pattern is ruined and cannot be reassembled somehow at the screen end. In other words, once you see planes departing, some for New York, some for Los Angeles, there is no way to have some of them arrive in St. Louis unless you bend their paths. Once you observe them at the slit, the inteference pattern is already ruined.

 

[LaurieAG]

Edit: I take it back. This would not work. As soon as the photons leave the slit, the interference pattern is already broken. Having once seen the photons past the slit, the interference pattern is ruined and cannot be reassembled somehow at the screen end. In other words, once you see planes departing, some for New York, some for Los Angeles, there is no way to have some of them arrive in St. Louis unless you bend their paths. Once you observe them at the slit, the inteference pattern is already ruined.

Yes, we would never expect to see just one plane going to both New York and Los Angeles but we could expect that, when multiple planes were involved, we could expect some of the planes that were going to either New York or Los Angeles would go to St. Louis if they were diverted there.

 

[Cthugha]

Doing the double slit experiment with a streak camera filming from the side would be pretty boring. The light that reaches the streak camera would consist solely of photons that get scattered by dust in the air or other impurities and willl therefore not be from the same set of photons that form the interference pattern.

Also, I think it is rather funny that these movies are promoted as being a technological breakthrough by the media. Streak cameras with specifications similar to the one used here exist for more than 10 years now. All they did was adding a lens assembly to get a wide field of view and they probably had some clever ideas on getting the highest possible dynamic range out of the camera. Movies of extended 2d scenes by measuring sets of 1d time resolved slices have also been created before routinely. However, people were usually interested in the micrometer distance range instead of the cm to m range used here.