The speed of light is a physical constant

>water molecules compress space like a black hole
even more retarded than the retards that thought it was just constantly being absorbed and re-emitted.

To follow up my post, let me inform you that field theories which have a variable speed of light (VSL) have been studied.
en.wikipedia.org/wiki/Variable_speed_of_light

Allowing a VSL amounts to changing the very structure of local spacetime, and at this point it goes over my head. Actually, this is the first time I've googled the subject, and I think it's quite interesting. Thanks OP, for giving me something to read about.

Its constant under all circumstances. Medium affects the apparent speed, not the actual speed

>matter can infinitely approach but never reach the speed of light
>photons

read a book, nigger.

>photons
Are not matter

physics sucks though

OP confirmed for not passing high school physics

u suk

If the speed of light is so constant then what's the deal with quantum entanglement

Doesn't break locality because it doesn't affect observables, i.e. it can't change the result of experiments.

c literally is the speed of light in "vacuum"

>particle
>not matter

Looking forward to high school?

>zero (0) rest mass
>matter
Looking forward to middle school?

>The speed of light in a vacuum stands at “exactly 299,792,458 metres per second“

>The metre is defined as the distance travelled by light in 1/299 792 458 of a second.

surely this is completely fucking stupid

>thinking mass and matter are the same thing
Looking forward to elementary school?

energy -> mass -> matter

photons have no mass

>The speed of light doesn't change.

you have no way of knowing this

see

Holy shit this a circular definition if I've ever seen one!

Physics BTFO!!!

>op is gay
>likes sucking dicks

If nothing can go faster than the speed of light. How fast was the Big Bang if it didn't include light?

Well how else would they keep it "constant"?

Why doesnt that make sense?

refraction means the light is deflecting from something, which means its not a vaccuum.

It's really more a "speed of causation" not speed of light, or you could say that maximus speed of everything ever is constant and is equal to speed of light in vacuum.

It doesn't change across medium. The reason it seems slower in a medium is that you also count the time between absorbion and emittion of light at the matter. Light ALWAYS travels at c.

Time is independently defined and speed of light is a constant. Meter is an arbitrarily chosen unit of distance. There is no circular reasoning. You're just basing the unit of distance on a constant.

Changes over time, too.

>the speed of light is a physical constant

No it isn't. The speed of light in a vacuum is. That speed doesn't change across mediums because all vacuums are vacuums.

lol books r for nerds

But why does light in a vacuum take primacy? Why is not the speed of light in a certain crystal a physical constant as well?
Could there not be a less impeding thing than vacuum though which light would travel at a higher speed?

>Time is independently defined and speed of light is a constant.

just saying it over and over doesn't make it true

Ahh, the bumbling fool returns.

Photons have no mass, yet they exert a force. Explain. None of you apparently understand that both einstien and max planck agree about this phenomena.

The big bang. You obviously mean the period of inflation which followed the big bang. Regardless of which, inflation refers to space expanding. This has nothing to do with light, rather photons are accelerated to the limit by the space around them.

> exert a force
> not change the geodesic

But mr. Frog the speed of light in a vacuum doesn't change.

That's why it shouldn't be called "speed of light", more like "speed of causality".

c is the speed of causality.

Light just goes c in a vacuum. It doesn't really have much to do with light. It's just the maximum speed oscillations of an electric and magnetic field can go.

Tesla never contributed anything to science. He's just a meme.

Do we even know if the speed of light is constant throughout the entire universe? What sort of phenomenon would we see if it varied in some regions of space?

>Thinks photons are matter

Holy shit this thread devolved overnight. The question was answered in the first 10 posts.

Matter fields obey the pauli exclusion principle because they have half-integer spin. Force (gauge) fields have integer spin and do not obey the pauli exclusion principle. As a result, you can freely add as many of them to a region of space as the imagination can handle. The same is not true of matter, like leptons and quarks, because they repel and occupy space. This would be true even if they were massless.
The Higgs has 0 spin, and is neither a matter field nor a force field. That being said, if you wanted to put an infinite number of higgs bosons in a box, you could (if it didn't cost energy because they are massive).

>Photons have no mass, yet they exert a force. Explain.

You want someone to explain the entire standard model to you? Fine.
The spontaneous symmetry breaking of the SU(2) symmetry in electroweak theory via the Higgs field removes the degrees of freedom inherent in the massless theory and essentially gives them to a combination of the 4 gauge bosons relevant in the electroweak theory. This freedom provided to the gauge fields allows for a new mode of polarization that can only be allowed for massive fields. Additionally, weak mixing organizes the two electrically neutral gauge fields so that one maintains it's gauge freedom and stays massless (the photon), while the other gains a mass (Z).
A similar process provides a mass to the matter fields and defines electrical charge for the electron and quarks. The electrically charged matter fields now can interact via an exchange of neutral, massless gauge bosons that transfer energy and momentum which we call "photons."

> The reason it seems slower in a medium is that you also count the time between absorbion and emittion of light at the matter.
Incorrect. Visible light is incapable of being absorbed by glass yet it still travels slower.

It's like highschool in here.

Are photons the smallest particles? If not, what's stopping them if they have no mass?

>Holy shit this thread devolved overnight.

It's a shitposting thread... move along.

More correctly, the speed of a light in a vacuum is constant

So why does the visible light slowes down in glass?

i suk your mum xD

Leave

c = 1

>less impeding thing than vacuum
Your mind?

>Car is going a constant speed
>Why does it take longer for it to travel 100m then 50m ??????!1???

That is literally how dumb you sound

What about gravity? It has a velocity that escapes even black holes.

Gravitational force isn't carried in discrete wave/particles like EM is. As such, gravity doesn't "escape" a black hole. Instead the mass associated with the black hole warps space-time around the black hole.

> inb4 gravitons

>cars ALWAYS travel the same speed
>except when they don't

Kill yourself, brainlet.

Of course it does. Measurement at one wing affects the results at the other. What's hard to understand?

>Conventional current is defined as the flow of positively-charged particles
>protons don't flow

>mfw scince is all about measurement
>They measure units with instruments and provide an average value
>Average significantly means it fluctuates
>"Oh yees! variables and environment caused the fluctuation its a constant trust me!!!"

photons behave like matter

How is this thread even alive? The speed of light is obviously not constant within different mediums, and not a single scientist ever claimed different.

en.wikipedia.org/wiki/Dispersion_(optics)

Interference from waves scattering and other waves being produced by the motion of the charged particles they travel by results in the total wavefront being slowed down in the material. In some materials, the phase velocity even speeds up. Unfortunately, it's not the phase of the wave that transmits information. Group wave velocity always slows down when you have interference.

In quantum field theory, there's a different (but mathematically equivalent) story. The photons couple with low frequency vibrational excitations in the material (essentially the jiggling of the atoms or free electrons) and effectively gain a mass (becoming polaritons), slowing down and thereby changing direction when in the material. The coupling is of course dependent on the frequency of the photon and the frequency of the vibrational mode. This is the cause of optical dispersion, as well as many other phenomena.
en.wikipedia.org/wiki/Polariton#Types

>photons behave like matter
When do they do that?

>How is this thread even alive?
Because nobody reads the long posts with big words.

Hehe
Meme

Physical constant for a vacuum.

>Invented the mind control devices the US uses to control its citizens
>Contributed nothing
Top kek, what an idiot

>replying to obvious bait
Just report and move on, peeps.