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Visualizing Photons in Motion at a Trillion FPS

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Re: Visualizing Photons in Motion at a Trillion FPS

#11

Post by stcredzero »

derefr wrote: post #6
stcredzero wrote: post #5

Earlier quoted context omitted.

Yes, but for certain extreme instances of bullet time indoors, I suspect the difference in intensity would be significant to the action. It would be like navigating a room at night with just one dim red LED providing light. Or else, people with that superpower would have to set off a flash-bang grenade when using their power.

Another interesting thought: bullet-time would seem colder. Depending on how things were supposed to be working (let's say your whole body was put into a different relativistic reference frame from everything around you), this would mean that things like air would become liquid/solid and impossible to move through. Interestingly, this would mean that you could have a civilization of Speedsters living comfortably insi…

Another interesting thought: bullet-time would seem colder.

Yes, but then you also have friction and the required speedup of energy consumption and heat generation. Drag and friction increases with the square of velocity, so going ludicrously fast is going to generate ludicrous heat.

Also recall that there's an absolute zero. Basically, there's limited downside and much greater potential upside.

Interestingly, this would mean that you could have a civilization of Speedsters living comfortably inside a star.

Or on a Neutron Star, as in Robert Forward's Starquake. (With the speedup coming from the much greater speed of strong force mediated nuclear reactions.)

Re: Visualizing Photons in Motion at a Trillion FPS

#12

Post by stcredzero »

pbhjpbhj wrote: post #9
derefr wrote: post #4

Earlier quoted context omitted.

The eye normalizes for orders-of-magnitude difference in luminance. Presumably, it makes for a good cinematographic choice to avoid the effect, for the same reason it would be grating to be hit with a lens flare every time a shot tracks from indoors to outdoors. On the other hand, bullet-time would, and should, be red-shifted , which is a whole 'nother thing.

> bullet-time would, and should, be red-shifted // How so? As I understood it bullet-time, eg in The Matrix, is an internal perception of time slowing; they're not changing the flow of time in the Matrix just choosing to perceive the computer generated scenes at a modified rate. The external "physics" is identical: Just as in a video player the images are fixed by the physics whether their presentation time correspon…

Perhaps we better not get in to a deep discussion of made-up physics?!?

Perhaps we'd better. Media physics misconceptions can produce hilariously large errors of scale.

Re: Visualizing Photons in Motion at a Trillion FPS

#13

Post by TeMPOraL »

ColinWright wrote: post #2

Lengthy discussion: https://news.ycombinator.com/item?id=3346609 Other submissions: https://news.ycombinator.com/item?id=3347267 https://news.ycombinator.com/item?id=3347793 https://news.ycombinator.com/item?id=3348210 https://news.ycombinator.com/item?id=3348427 https://news.ycombinator.com/item?id=3348679 https://news.ycombinator.com/item?id=3349278 https://news.ycombinator.com/item?id=3349614

ColinWright, HN's own biological duplicate content detection bot ;).

(disclaimer: I find what you do very valuable, please keep doing that)

Re: Visualizing Photons in Motion at a Trillion FPS

#14

Post by tritium »

This photography isn't really about "photons" or any amount of energy measurements of radiation emission at the subatomic scale. This is more about capturing macro-scale events at very precise time scales and exceedingly high shutter speeds, and detecting how quickly an arbitrary amount of light will traverse the components of a still life.

There's also a lot of distortion introduced into the final composited images, enough that they cease to look like photographs of normal physical objects, and start to look more like computer generated images of ray traced 3D models.

Re: Visualizing Photons in Motion at a Trillion FPS

#15

Post by bobbles »

stcredzero wrote: post #3

One of the things that are unrealistic about "bullet time" as portrayed in games and movies, is that the world doesn't dim as time slows down. Slow the rest of the universe down, and the amount of light energy entering your pupil per unit time slows down as well. One of the things that came up in the criticisms of Khan Academy's teaching of slope/rate is that lots of people don't internalize a conception of sensory i…

I generally interpret these scenes as the individual speeding themselves up to an insane level and everything else 'appears' to slow down in comparison.

Maybe this is why everyone in the Matrix is wearing black sunglasses 24/7

Re: Visualizing Photons in Motion at a Trillion FPS

#17

Post by kibibu »

lcrs wrote: post #10
jerf wrote: post #8

Earlier quoted context omitted.

It depends on your "bullet-time" model whether it's red-shifted or not. Much "bullet-time" is explicitly just a special effect, i.e., the idea is that the action is still occurring in real time but we're having it slowed down so we can see it, understand it, and enjoy it. In that case we are simply shooting the scene with a high-FPS camera. "Technically" we should indeed get a dimmer scene, just as real high-speed ca…

Even cameras which vary speed during an unbroken shot automatically compensate so the exposure stays the same, but doing so has other interesting effects, depending how it's done: a) Compensating with shutter so that the integration time is constant means the quality of motion blur changes during the ramp. For example a shot that starts at 24fps and ramps to 120fps keeping a shutter time of 1/240th would start out wi…

I believe for the action scenes in 300 they recorded the whole lot at 120fps and selectively dropped or merged frames to get back to 24fps
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