Uh, that discovery actually predated Einstein. He simply explained how the speed of light was constant for all observers
To be more accurate actually, he and his first wife explained it
You mean Mileva Marić and her husband?
I was blanking on her name. Sadly she is almost never given the credit she deserves
Didn’t want to make you fell like you have defend yourself, just wanted to turn it around and shitpost. But yeah, she rarely does.
I was also lowkey referencing the famous photo caption from am interview with “Amal Clooney, famous and successful lawyer and human rights activist, and her husband, an actor”. Referring to a certain George.
Oh I didn’t feel like you were attacking me, rather I appreciated you posting her name
ಠ_ಠ
This is unaceptable…you have to be assholes to each other.
He also discovered that the speed of light equals c.
Where c is defined as the speed of light
And that’s why we take vitamin C!
And why pirates drink coffee. “Boo, tea!” they cry
Weak
Now you know how I felt through this whole comment chain
And it is remarkably consistent at doing that.
Relatively consistent.
*in vacuo
But when you think about light’s speed in medium it seems like absorption and re emission which shifts light’s net velocity. The speed of light between the interaction is still c. That becomes obvious if you zoom into matter and find its mostly empty likr vaccum
No, that’s not really a useful way of modeling it for the case of light traveling through a linear medium.
The absorption/re-emission model implicitly localizes the photons, which is problematic — think about it in an uncertainty principle (or diffraction limit) picture: it implies that the momentum is highly uncertain, which means that the light would get absorbed but re-emitted in every direction, which doesn’t happen. So instead you can make arguments about it being a delocalized photon and being absorbed and re-emitted coherently across the material, but this isn’t really the same thing as the “ping pong balls stopping and starting again” model.
Another problem is to ask why the light doesn’t change color in a (linear) medium — because if it’s getting absorbed and re-emitted, and is not hitting a nice absorption line, why wouldn’t it change energy by exchanging with the environment/other degrees of freedom? (The answer is it does do this — it’s called Raman scattering, but that is generally a very weak effect.)
The absorption/emission picture does work for things like fluorescence. But Maxwell’s equations, the Schrödinger equation, QED — these are wave equations.
I wouldn’t say its a useful way, but if you think about it, everything is vaccum if you zoom enough. Also absorption can mean different things though so keep that aside and think of it as some interaction going on which in effect slows it down.
Now i looked up on youtube and this is what i meant (timestamp included). I was looking for 3b1b explaination but this one works too. It’s arguable if we can call it absorption or not, and what I said before might be ambiguous. But this guy explains it well
Edit: The 3b1b explaination is either in this video or in this one or maybe a combination of both
Yes, but light always travels at the speed of light, regardless of its speed. It travels at c in a vacuum.
Dispersion and nonlinearities would like to have a word ;)
I’m reasonably sure that Einstein’s breakthrough was more that he assumed light only travels at the speed of light and the all the equations worked.
Every experiment since has confirmed it.
Technically everything moves at c (the speed of light) through spacetime, all the time. Most objects that have mass spend the majority of their motion in the time part, and thus move relatively slowly in space. If an object moves fast in space (where fast is a significant fraction of c) then it moves noticeably slower in time because the total spacetime vector value is always c.
Photons, being massless, do not move through time at all, and move through space at c.
That’ll break a few brains. To elaborate with an example: From the perspective of a photon, it’s “life” is over as soon as it begins. Even though it takes about 8 mins for a photon to travel from the sun to the earth from our perspective, no time at all has passed for it.
(Correct me if I misspoke.)
Light is generally better modeled by a wave, so I would say the wave doesn’t experience time. Photons are the smallest unit of energy that can be transferred between a light wave and a different particle. They have momentum and direction, but they don’t really travel exactly. They just mediate the force between light waves and matter.
Worded differently, a fermion (massive particle) within an electromagnetic (light) wave with a frequency of f may absorb some multiple of h x f joules of energy, where h is a very small constant. There is no way for the wave to transfer less than hf joules to the particle at a time. There is no need to think of photons as anything other than the smallest possible quantization of the electromagnetic wave rather than a particle of light. There’s no need to think of it existing for any amount of time or space.
Photons are the smallest unit of energy that can be transferred between a light wave and a different particle.
That is a much better description than what I have heard for the last 30 years: “A photon is a packet of energy”. That made no sense to me back then, and makes no sense to me now and, IMHO, doesn’t quite give a good visualization. It’s a placeholder, and I suppose it is slightly accurate depending on how “packet” is defined.
That’s awesome, and I totally agree. Everyone already intuitively knows that waves carry energy. We’ve all heard of tsunamis and earthquakes. The only difference on the quantum scale is that the amount of energy transferred is discretized.
To add to this, this is always relative to an observer. If an object moves fast in space compared to you then it moves slower in time compared to you.
Any speed that light travels is the speed of light
The real breakthrough
The other way around. Experiments said that light always moves at C and he deduced what follows from that for space time.
Uh, Einstein was Jewish and Hugo Boss made the SS uniforms. This is a bit odd.
Yeah, but is it a wave or a particle, eh, Einstein? Answer that!
Yes.
Holy Minkowski spaces, Batman! It’s the old man himself!
Well, he did get a Nobel price for saying it’s a particle.
Camera: *flash*
“Fuck you photons, next time. Again.”
Put a monocle on him and make it The Speed Of Causality.
