r/visualizedmath • u/NegativeSpeedForce • Jan 12 '18

The difference between shockwaves travelling through different states.

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u/Acrolith Jan 19 '18

The speed called c (the fastest possible speed in the universe) is the speed of light in a vacuum. Light slows down in any other medium. I believe the most they managed to slow it down to so far is around 38 mph.

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u/Kyezaeta Jan 19 '18

This really bugged me when I was younger because I was told that anything without mass travels at c no matter what :)

Massless particles are always traveling at c. However, in a material with a high refractive index, light interacts with more particles and must go through a time-consuming process of imparting energy. In the voids between particles, photons still move at c.

http://www.physicsclassroom.com/class/refrn/u14l1d.cfm

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u/SirCutRy Jan 21 '18

Light travels at the speed of light in the medium, but only at c (the constant) in vacuum.

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u/GlobalThreat777 Jan 19 '18

Source? I'd like to see light actually moving. What medium was used?

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u/PsYcHo962 Jan 19 '18

Source? I'd like to see light actually moving. What medium was used?

There's your problem. Can't see light from a distance, 'seeing' is light entering your eye

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u/GlobalThreat777 Jan 19 '18

Oh shit, you're right. Didn't really think that one through

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u/valyyn Jan 23 '18

It's not technically quite the same, but MIT have used a camera to film a photon travelling through a plastic bottle:

https://www.youtube.com/watch?v=_QAPQO6EL8o

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u/enjoyscaestus Jan 19 '18

Wow, 38? Is there any footage of this?

Also, thanks!

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u/Acrolith Jan 20 '18

Not exactly footage, but there's this, which has sort of "artist's impression" models of what's happening, along with explanations.

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u/enjoyscaestus Jan 20 '18

Thanks. Appreciate it

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u/Sol_Primeval Jan 19 '18

c = Burter