Why does light slow down in glass? 

Your videos are great! However consider the definition of a lie: "an intentionally false statement." Making incorrect statements is not necessarily lying. I don't think that anyone is lying when trying to explain the speed of light. Be careful when saying that science lies. We have a crisis in our country where people are less believing in science. We don't want to encourage that trend. That is dangerous to society. Perhaps a better title would be, "The Biggest Misunderstanding in Science!"

I think 1 thing is missing here: the actual speed of light in the usual sense is not the phase velocity, but the group velocity at the front of the wave packet (which determines when the first part of the wave packet hits something). The light wave didn't exist for all time, but the 1st part of the light wave reach the electron at some time, and only after that the electron can also oscillate. So even in the case of x-rays, the group velocity would still be the vacuum speed of light, but the refraction is determined by the phase velocity, which is why x-rays are refracted away from the vertical.

Why is it always the channels with fewer subscribers that have the best explanations? You could not have explained this better!

But why would it bend? If any explanation is there it should also explain the total internal reflection as the bend is proportional to refractive index and as it increases the total internal reflection happens? This does not explain.

Are you from khan academy😅😅😅,btw you are my best physics coach ❤ u

Very good. The video from Fermilab got me halfway there but I was still unsatisfied because he didn't go into how the delay of the phase of the forced wave can vary depending on frequency. The x-ray thing too was surprising. I am now satisfied to the extent that I want - I don't feel like slogging through papers because I'm way too lazy for that! Thank you much!

After watching your video its my time to showoff my knowledge in physics to my friends....i am sure that i blown their minds exactly like what you did to me 🤯🚶🚶💯

Sir i think this was all about the speed of wave which you explained beautifully and someone has a good knowledge of interference can understand it easily but you did not explained why it bends? Or did I missed something 👀

So if you put like 999999999 layers of glass, speed of light will look very slow(around 1-10 m/s) in our eyes?

Only phase should change with this interaction and not time to travel. It looks like pulled back but wave is not actually pulled back, it just has amplitude change. So it should reach other end at the same time. Why it slowed down is not clear.

Wow!!..blown away ...thankx mahesh...u r the best educator ever i seen on youtube...no one explained that way,they spoon feeded on this platform about light

That's one of the best videos on the internet! I really appreciate your work, because we don't have this kind of depth in high school's physics (speaking from Brazil here), so it's really great to understand it properly!

I truly appreciate your content that you put on youtube,,,you are one of the best teacher delivering quality content,,,please do post more videos including dispersion of light ,i would love to have it...

I like how you actually wave your hand when you get into the hand waving explanation.

Best and fastest and most intuitive.explanation I've found on internet about the ligth transmission through a material. Before your explanation I had seen unclear explanations from some other well known physics youtubers, and I was a little clueless. Thanks for your clarity and simplicity. I really appreciate it, since it's not easy.....

Wow. I found your videos just recently. I have an engineering degree from a long time ago and I wanted to understand special relativity. I have some textbooks. I’ve watched a lot of different videos. Your videos are outstanding. Thank you so much!

I have struggled with these concepts for years . Thanks to your explanations, physics has now become so much more interesting, and easy to understand.

This is a brilliant explanation of something I had never even considered. It's almost 60 years ago since I was in college studying Microwave theory, which covered a lot of the same ground - wave phases adding or subtracting - but it was on a space commuications course (NASA), and we didn't go into optics. I knew from general interest how light refracts in glass, and I had always accepted on faith that it is because it slows down in media denser than free space, but the idea that it doesn't slow down - it just takes longer to traverse a glass block of fixed dimensions - is a relativistic thing - and Relativity is not intuitive. But I didn't know that X-rays refract away from the normal.

I love how u used topics that are familiar with everyone to describe this crazy phenomenon .Keep up the good work.

I can't believe how good this explanation is. Amazing