Electromagnetism, Light and Energy: The Best Science Videos on Magnets, Fields, and Thermodynamics
See our guides to Electromagnetism, Thermodynamics, and Optics and Light.
Magnetism, the Force You Can Feel
Hold two magnets near each other and you feel a force reaching across empty space. Asking why that happens leads somewhere far deeper than most people expect.
Why Do Magnets Attract, at a Fundamental Level?
"Why do magnets attract?" sounds simple until you try to answer it without just saying "magnetism." Arvin Ash goes all the way down, through moving charges and even a touch of special relativity, to the genuine reason. One of the most satisfying "why" videos in all of physics.
Read next: Electromagnetism Explained.
The Tiny Donut That Proved We Still Don't Understand Magnetism
A strange quantum experiment with a ring-shaped magnet shows that the magnetic field is not the whole story, and that the potential behind it is somehow real. Veritasium uses it to reveal how much about electromagnetism is still genuinely open at the deepest level.
Read next: Electromagnetism Explained.
Energy and the Laws It Obeys
Energy is the most important quantity in physics and the hardest to define. These two get at the rules that govern it, including one of the most elegant ideas in all of science.
Why Can't Energy Be Created or Destroyed?
Conservation of energy is the rule everyone learns and almost no one can explain. Arvin Ash connects it to a deep and beautiful result: conservation laws arise from symmetries in nature. Once you see that link, energy stops being a mystery and becomes inevitable.
Read next: Thermodynamics Explained.
Maxwell's Demon Reveals a Shocking Truth About Information
A 150-year-old thought experiment seems to let you cheat the second law of thermodynamics, until you realize that information itself carries a physical cost. This is the clearest telling we found of how thermodynamics and information theory turn out to be the same subject.
Read next: Thermodynamics Explained.
Entropy, Fields, and the Deep Rules
The last two go to the strangest corners of this territory: how ordered life can emerge from a universe that tends toward disorder, and whether the old idea of a medium filling space ever really went away.
How Did Life Arise from Increasing Entropy?
The second law says disorder always increases, so how did something as ordered as life ever appear? Arvin Ash resolves the apparent paradox, and the answer quietly reshapes how you think about energy, entropy, and living things all at once.
Read next: Thermodynamics Explained.
Did Physics Secretly Bring Back Aether?
Physics threw out the old idea of a light-carrying aether more than a century ago, yet modern field theory has something that plays a oddly similar role. A thoughtful look at what the fields filling apparently empty space really are, and how light moves through them.
Read next: Optics and Light.