Why does light bend when it enters glass?
Why Physics Stack Exchange recommends it
Physics Stack Exchange users link it when asking or answering why light refracts, usually as an accessible account of the electromagnetic-field mechanism and a counter to the common wavefront-addition explanation.
Recommended by 4 people across 4 different months, 2020 to 2022.
What it is
A Fermilab explainer in which physicist Don Lincoln explains why light changes direction when it passes into glass or another medium. He argues that several popular explanations are wrong and presents the account based on the light's electromagnetic field interacting with the charges in the material. A correction note says the plus and minus charge directions at 12:02 are shown backward.
What people said
Recommends Zorawar · 2020-04 · Physics Stack Exchange · on “Intuitive explanation for why blue light is refracted more than red light?”
Unfortunately, there's no easy explanation for this. It involves some basic atomic physics, so you will need a picture of how electromagnetic fields interact with matter. Consequently, some of this may be difficult to understand, but hopefully you can ask about (or read up) whatever you don't understand. Semoi's answer is correct, but a lot of details have been left out. I will try to fill in some of the gaps. Semoi's description is the modern semi-classical understanding of the process, but we can step back to the older Lorentz-Lorenz model to understand the essential idea. I'll explain all this in what follows. What is happening when light refracts is that when the electromagnetic wave (th
Recommends KP99 · 2021-11 · Physics Stack Exchange · on “If light is an oscillating magnetic field, why doesn’t it induce an EMF according to lenz’s law”
Yes, in presence of charged particles it will induce some non-zero EMF. This propagating light will produce some back-reaction and this leads to phenomena such as refraction, so your idea is partially correct but incomplete. See this explanation by Dr. Don : [this video]
Recommends le hollandais volant · 2021-12 · Physics Stack Exchange · on “How can you explain refraction of a single ray of light while entering in denser medium from rarer?”
The light ray is composed of an electromagnetic field. This can be separated into its electric component and its magnetic nomponent. You can find the magnetic part using the electric part and some math, so let’s focus on the electric field only. The electric field is perpendicular to the direction of propagation. Lets assume that the ray falls on a horizontal surface of some water with an angle. The direction of the electrical wave can be separated into its tangential part (parallel to the water surface) and the normal part (perpendicular part). On the air-water boundary, the tangential part is continuous: it does not change (see Maxwell equations). So the « left-to-right » component is the
Recommends Zitscx ø · 2022-01 · Physics Stack Exchange · on “Why does light bend when it enters a medium?”
I am asking this question after referring to @benjimin answers at Why does light bend? [LINK] I found the same answer at wiki. But i found a video on youtube by doctor don ( [this video] ) claiming that method to be wrong and here is why- According to the old explanation the waves add up and move at at different angle due to slowed speed. It looks somewhat like this - (image from the vid) [LINK] But there are also other wavefronts adding up together and going different ways. like- [LINK] So with different wavefronts aligning in different direction, many waves propagate in different directions and this is not observed in reality and hence this explanation proves wrong. Now, Doctor Don explains tha
Cites Rajdeep Sindhu · 2020-04 · Physics Stack Exchange · on “How does the car analogy explain refraction of light?”
Check this out : [this video] I didn't get much of it but this is the video that I was referring to in my last comment