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Speed Of Light Is Not Always The Fastest!

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Speed Of Light Is Not Always The Fastest!


But the only thing faster is light!


Good video and well produced, I would say it is almost 'text book' spot on.


As for Maxwell I doubt he calculated that c was constant, I assume he observed (by experiment) that it was constant and based his calculations on that observation, in most of science you don't really end up with a final number unless you first apply some numbers from observations or experiment. 

You need some base numbers to plug into the equations first.


The permittivity and permeability of free space is more about the ability of a medium to electric or magnetic fields and 'in a vacuum' is the 'base energy' required to 'conduct' those fields in 'no medium'. 


So for example say you have a heater element in a box, you want to heat that heater to 200c it will require different amounts of energy to get it to that temperature as a function of the properties of the medium in the box with the heater. 


'In a vacuum' means that base energy it would require to heat the heater with NO medium in the box, (in a vacuum), so that is how I would consider permittivity and permeability, I do that because in my opinion light is not really coupled to space (or  time). That is space is not a medium at all, it's not an aether, but it still takes a base energy to created the coupled electric and magnetic field transient that is what we consider light.


And, of course even in a medium light still goes at the same speed, (between the bits of matter), but the light a bit of a 'random walk' in the medium, and therefore takes a longer path, same speed but longer path.


I expect when you deal with relativity you will address why it is constant and why it is the fastest you can go.


But good vid, keep on knocking them out and build up your channel, the more fundamental science channels the better, and I can't really fault your vid at all. I subbed you.

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Thank you for the detailed comment about the materials discussed in the video. It is really helpful for a content creator like me to consider in preparing new contents. So, I really appreciate your time that you took to write it.

I would like to share my opinions on some points you made.

As explained in the video, the constant "c" is actually not the speed of light. Therefore, one would not need to experiment light to calculate it. It is derived from Maxwell's equations. We have two constant numbers, permittivity and permeability or electric and magnetic constants of free space. We do have these numbers. Then Maxwell realized that the speed of a massless electromagnetic radiation would be constant in free space, c, which he derived from his equations as c=1/sqrt(Eo × Mo), where Eo and Mo are the permittivity and permeability of free space (which are known). Then, since light and other EM radiations are massless EM radiations, then they would travel with "c" in vacuum of space. This is why and how "c" was named as the speed of light in vacuum.

As for the speed of light, you are right, the light still travels with "c" between the atoms. But we can argue that "it is only because the space between the atoms is vacuum". [emoji16]

Anyways, your explanation is good, but not the best. Considering light as behaving like particles, photons, and bouncing back and forth between the atoms would not explain why the light only moves in a particular direction in a medium. Therefore, it is better to consider the motion of light in a non-vacuum / dielectric medium as EM waves. Then you will have a better explanation for how the light interacts electromagnetically with the atoms and molecules of the medium and how it keeps moving in a particular direction with a slower "displacement" speed.

For the space, it is actually something, like a medium, which can be bent by a strong gravity. It even has an energy, which we call as Dark Energy. It is not the receding of far away galaxies that is expanding the universe, but it is the vacuum of space itself which is expanding and taking far away galaxies even further away. We have published a video on this subject that you may be interested. It is also related to how we know the space is something.

Video: "This is How The Universe is Expanding Faster Than Light"


PS: Thanks for subscription [emoji120][emoji106][emoji4]

Edited by ScienceAndUniverse
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