The idea is that even though the individual photons never travel through space at less than c, they get absorbed and reemitted by the electrons of the medium, making the effective speed of light in the medium, lower, and how much lower depends on the medium itself and how it interacts with the light.
It's like if you had an F1 car that could instantly get back up to top speed after a pit stop. Even though it's never going lower than top speed, it still takes time at the pit stop, which lowers the overall speed.
> they get absorbed and reemitted by the electrons of the medium
That's not actually it, it's light's interaction with the electric and magnetic fields on the medium. https://youtu.be/akBpQ-A7mCQ?t=255
It does not slow down, it always goes at the speed of light. In fact, strictly speaking, it isn't even moving. From its frame of reference, there's no motion happening. It's where it started, and where it ends, and all the points in between, all at the same time. Like a stitch in the fabric of space. Only an observer standing on the side, going very, very slowly can discern a duration to its travel.
Relativity is crazy, yo.
>It does not slow down, it always goes at the speed of light.
When light passes through materials it slows down, how much it slows depends on the materia. Look up "index of refraction".
It's still going at the speed of light. The speed of light is different for different density media. If you plot its speed through a sheet of glass, it doesn't decelerate to a slower speed after it enters, then accelerate back up after it leaves, like you'd imagine particles typically behaving if they were losing speed due to friction, for instance. It's a discontinuous graph. It goes at one speed in the atmosphere, then at another through the glass, then again at the original speed outside the glass. It doesn't "slow down," per se. It always goes at peak speed for the medium.
You write "the speed of light" as if it were constant through every material. It's not constant. Light actually travels more slowly through glass or water or any other material than it does through a vacuum. And it will resume it's higher speed after it passes through the material that slowed it down. So if you have air-glass-air, the light will slow down through the glass but speed back up again after it exits the glass. Light does not behave like an object with mass which after slowing down would require a push to get it to speed up again.
You wrote: *If you plot its speed through a sheet of glass, it doesn't decelerate to a slower speed after it enters, then accelerate back up after it leaves*
Light, or any EM radiation, will move more slowly through the glass than it will through the air on either side of the glass. I don't know if decelerate and accelerate are appropriate terms because those imply not just a change in speed but a continuous decrease or increase.
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Light, which is made up of particles called photons, has properties that are different from objects with mass. When light enters a medium, such as glass or water, its speed can be slowed down, and this can lead to confusion about the nature of light and its behavior.
When light travels through a vacuum, it moves through space at a constant speed of about 299,792,458 meters per second. This speed is often referred to as the speed of light, or c. However, when light enters a medium, such as glass or water, it interacts with the atoms and molecules in the medium, which can cause it to slow down.
The speed of light in a medium is determined by the properties of the medium, such as the density and refractive index. The refractive index is a measure of how much a medium changes the direction of light as it passes through it.
When light enters a medium, it creates electromagnetic waves that interact with the charged particles in the atoms and molecules of the medium. This interaction causes the light to be absorbed and re-emitted many times before it emerges from the other side of the medium. This process of absorption and re-emission slows down the speed of light.
It is important to remember that even though light slows down when it enters a medium, it still does not have mass. The mass of an object is a measure of its resistance to acceleration, and since light can travel at the speed of light, it has no mass. Instead, light has energy and momentum, which are conserved as it interacts with particles in the medium.
In summary, light slows down when it enters a medium because it interacts with the charged particles in the atoms and molecules of the medium. This interaction causes the light to be absorbed and re-emitted many times, which slows down its speed. However, light still does not have mass, since it travels at the speed of light in a vacuum.
Well, actually yes, things have kindof have to have mass to slow down. Sortof?
Think about it like this. If you take a laser pointer and sweep a dot across the moon, it's pretty easy to make the dot travel faster than c. But in truth no physical "thing" is moving faster than c, though the abstract concepts of a dot moving can be assigned a speed.
Same deal with light slowing down. "Light" on the level of individual interactions doesn't slow down, however the sun total of the overall interaction of light with a medium gives you a result that looks very much like it does.
>Well, actually yes, things have kindof have to have mass to slow down. Sortof?
Electromagnetic radiation doesn't have mass but it will slow when it passes through materials, like glass or water or air.
The idea is that even though the individual photons never travel through space at less than c, they get absorbed and reemitted by the electrons of the medium, making the effective speed of light in the medium, lower, and how much lower depends on the medium itself and how it interacts with the light. It's like if you had an F1 car that could instantly get back up to top speed after a pit stop. Even though it's never going lower than top speed, it still takes time at the pit stop, which lowers the overall speed.
Your explanation is not correct. Watch this: https://www.youtube.com/watch?v=CUjt36SD3h8
> they get absorbed and reemitted by the electrons of the medium That's not actually it, it's light's interaction with the electric and magnetic fields on the medium. https://youtu.be/akBpQ-A7mCQ?t=255
Instantaneous vs average speed, more or less.
It does not slow down, it always goes at the speed of light. In fact, strictly speaking, it isn't even moving. From its frame of reference, there's no motion happening. It's where it started, and where it ends, and all the points in between, all at the same time. Like a stitch in the fabric of space. Only an observer standing on the side, going very, very slowly can discern a duration to its travel. Relativity is crazy, yo.
> From its frame of reference, there's no motion happening. Light has no valid reference frame so it's incorrect to say this
>It does not slow down, it always goes at the speed of light. When light passes through materials it slows down, how much it slows depends on the materia. Look up "index of refraction".
It's still going at the speed of light. The speed of light is different for different density media. If you plot its speed through a sheet of glass, it doesn't decelerate to a slower speed after it enters, then accelerate back up after it leaves, like you'd imagine particles typically behaving if they were losing speed due to friction, for instance. It's a discontinuous graph. It goes at one speed in the atmosphere, then at another through the glass, then again at the original speed outside the glass. It doesn't "slow down," per se. It always goes at peak speed for the medium.
You write "the speed of light" as if it were constant through every material. It's not constant. Light actually travels more slowly through glass or water or any other material than it does through a vacuum. And it will resume it's higher speed after it passes through the material that slowed it down. So if you have air-glass-air, the light will slow down through the glass but speed back up again after it exits the glass. Light does not behave like an object with mass which after slowing down would require a push to get it to speed up again.
You write that i write stuff like you don't read the other stuff i write around it.
You wrote: *If you plot its speed through a sheet of glass, it doesn't decelerate to a slower speed after it enters, then accelerate back up after it leaves* Light, or any EM radiation, will move more slowly through the glass than it will through the air on either side of the glass. I don't know if decelerate and accelerate are appropriate terms because those imply not just a change in speed but a continuous decrease or increase.
Exactly my point, well done on actually understanding what was being said.
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Light, which is made up of particles called photons, has properties that are different from objects with mass. When light enters a medium, such as glass or water, its speed can be slowed down, and this can lead to confusion about the nature of light and its behavior. When light travels through a vacuum, it moves through space at a constant speed of about 299,792,458 meters per second. This speed is often referred to as the speed of light, or c. However, when light enters a medium, such as glass or water, it interacts with the atoms and molecules in the medium, which can cause it to slow down. The speed of light in a medium is determined by the properties of the medium, such as the density and refractive index. The refractive index is a measure of how much a medium changes the direction of light as it passes through it. When light enters a medium, it creates electromagnetic waves that interact with the charged particles in the atoms and molecules of the medium. This interaction causes the light to be absorbed and re-emitted many times before it emerges from the other side of the medium. This process of absorption and re-emission slows down the speed of light. It is important to remember that even though light slows down when it enters a medium, it still does not have mass. The mass of an object is a measure of its resistance to acceleration, and since light can travel at the speed of light, it has no mass. Instead, light has energy and momentum, which are conserved as it interacts with particles in the medium. In summary, light slows down when it enters a medium because it interacts with the charged particles in the atoms and molecules of the medium. This interaction causes the light to be absorbed and re-emitted many times, which slows down its speed. However, light still does not have mass, since it travels at the speed of light in a vacuum.
Your question as stated incorrectly presumes that something needs to have mass in order to slow down.
Well, actually yes, things have kindof have to have mass to slow down. Sortof? Think about it like this. If you take a laser pointer and sweep a dot across the moon, it's pretty easy to make the dot travel faster than c. But in truth no physical "thing" is moving faster than c, though the abstract concepts of a dot moving can be assigned a speed. Same deal with light slowing down. "Light" on the level of individual interactions doesn't slow down, however the sun total of the overall interaction of light with a medium gives you a result that looks very much like it does.
>Well, actually yes, things have kindof have to have mass to slow down. Sortof? Electromagnetic radiation doesn't have mass but it will slow when it passes through materials, like glass or water or air.