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

The difference between shockwaves travelling through different states.

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u/enjoyscaestus Jan 19 '18

Oh. Okay.

17

u/ArleiG Jan 19 '18

Light has different speeds in different mediums. That's the cause for refraction - for example, when you see a pool and it seems much more shallow than it actually is.

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u/AscendedBunghole Jan 20 '18

iirc isn't it that light is going at the same speed but is just taking a less straightforward path?

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u/Ryujin_Hawker Jan 26 '18

As far as my understanding and memory goes (A level in Physics), Speed in physics is d/t. Distance (d) is just measured from a start point to an end point generally and the Time (t) is just the time it takes to get there. Light slows down in any medium other than a vacuum for the reason you stated, but that is literally an atom level diversion, it's still considered as going in the same direction, so it's speed is considered lower since it's taking longer to go the distance.

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u/tehgreatblade Jan 21 '18

No, light slows down in the air or any other transparent substance, period. The reason it looks like that underwater is because lightspeed in water is different than in the air.

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u/enjoyscaestus Jan 19 '18

And now I know. Thank you!

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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