this post was submitted on 19 Nov 2023
346 points (93.2% liked)

Science Memes

10988 readers
3142 users here now

Welcome to c/science_memes @ Mander.xyz!

A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.

Rules

  1. Don't throw mud. Behave like an intellectual and remember the human.
  2. Keep it rooted (on topic).
  3. No spam.
  4. Infographics welcome, get schooled.

This is a science community. We use the Dawkins definition of meme.

Research Committee

Other Mander Communities

Science and Research

Biology and Life Sciences

Physical Sciences

Humanities and Social Sciences

Practical and Applied Sciences

Memes

Miscellaneous

founded 2 years ago
MODERATORS
Sal@mander.xyz
fossilesque@mander.xyz
SciBot@mander.xyz
346
Speediest little fella. (mander.xyz)
submitted 1 year ago* (last edited 1 year ago) by fossilesque@mander.xyz to c/science_memes@mander.xyz
61 comments fedilink hide all child comments
 

!physics@mander.xyz

you are viewing a single comment's thread
view the rest of the comments
[–] Neato@kbin.social 6 points 1 year ago (2 children)

That's light as an aggregate wave. Photons, actual light, always travel at c. What's happening in a medium is the rapid absorption and readmission of photons. The probability of admission is based on structure of material causing things like lens or mirrors to work.

You can think of it as the photons having to jump between platforms before the can continue running at c.

[–] Entropius@lemmy.world 3 points 1 year ago (1 children)

What's happening in a medium is the rapid absorption and readmission of photons. […]

You can think of it as the photons having to jump between platforms before the can continue running at c.

That’s an intuitive model, but unfortunately it doesn’t have the advantage of actually being correct. Photons are not being absorbed and reemitted. See here for why: https://lemmy.world/comment/5444224

[–] Neato@kbin.social 0 points 1 year ago (1 children)

That is wrong. Stochastic yes. Photons emission is probabilistic. Destructive interference causes emission to overwhelming follow classical wave theory. Here's a better explanation with a neat graphic.

https://physics.stackexchange.com/questions/466/what-is-the-mechanism-behind-the-slowdown-of-light-photons-in-a-transparent-medi

[–] Entropius@lemmy.world 2 points 1 year ago

It sounds like you’re conflating different concepts. A stochastic process like absorption/reemission would blur the light, so that’s not it. And the linked explanation is basically correct (in classical physics at least), but it doesn’t corroborate what you originally claimed as that’s not necessarily requiring absorbing anything. Photons can jiggle the charged particles in glass and get them to make new phase shifted light despite not being absorbed.

https://youtu.be/YW8KuMtVpug

https://youtu.be/CiHN0ZWE5bk