u/soggytime07

Newton's 3rd Law is one of the first things you learn in physics. But what if it's not actually a law it's a consequence of something much deeper?
In this video we derive Newton's 3rd Law from scratch using momentum conservation, then ask the question nobody asks in school: where does momentum conservation even come from?
The answer takes us to Emmy Noether's theorem one of the most profound results in all of physics and reveals that every conservation law you've ever learned is secretly a symmetry of the universe in disguise.
But here's the thing. Noether's theorem is only as strong as the symmetries it assumes. And the universe doesn't always cooperate.
What we cover:

Deriving Newton's 3rd Law from momentum conservation
Why momentum is conserved the real reason
Noether's theorem: symmetry to conservation law
Translational, rotational and time translation symmetry
Why Newton's 1st Law and Noether's theorem have the exact same problem
Where time translation symmetry actually breaks and what that means for energy conservation globally

This is the rabbit hole behind the law your textbook treats as obvious.

Ever wonder why the angle of incidence equals the angle of reflection? Most textbooks just tell you to memorize it, but in this video, we break down sound waves into their vector components to prove it mathematically.

Using the Manim animation engine, we explore:

• How to represent sound rays as vectors.
• Using trigonometry to find horizontal and vertical components.
• The physics of what happens when a wave hits a rigid boundary.

Perfect for Class 9–11 students or anyone who wants to see the "how and why" behind the laws of physics.

Ever wonder why the angle of incidence equals the angle of reflection? Most textbooks just tell you to memorize it, but in this video, we break down sound waves into their vector components to prove it mathematically.

Using the Manim animation engine, we explore:

• How to represent sound rays as vectors.
• Using trigonometry to find horizontal and vertical components.
• The physics of what happens when a wave hits a rigid boundary.

Perfect for Class 9–11 students or anyone who wants to see the "how and why" behind the laws of physics.

In school, we’re taught that light bounces off a mirror like a billiard ball. But if light is a wave, why doesn't it just splash everywhere?

I made this animation in the style of 3b1b to explore the deeper reality: reflection is actually a result of trillions of waves interfering with one another. When the phases don't align, they destroy each other; when they do, we get the "Law of Reflection."

It covers Huygens' Principle and Fermat's Principle of Least Time, showing how geometry and wave mechanics converge into one elegant rule. I'd love to hear what the community thinks of this visual approach to optics!