Principia
@principiah.bsky.social
Stories of physics and the cosmos. A documentary series on how humanity discovered electricity, one experiment at a time, with the physics computed, not just told. New episode every week.
https://www.youtube.com/@principiah
https://www.youtube.com/@principiah
29 August 1831. Faraday connects a battery to a coil on an iron ring. The needle on a second coil jumps, falls back to zero while the current still flows, and jumps the other way when he disconnects. Every generator and transformer is that ring.
Ep. 7 of How Humanity Discovered Electricity
#histsci
Ep. 7 of How Humanity Discovered Electricity
#histsci
Lines of Force: Faraday and the Experiment That Powers the World | Electricity, Ep. 7
Faraday, induction and the lines of force. Principia, 17 min.
youtu.be
September 18, 2026 at 10:14 AM
29 August 1831. Faraday connects a battery to a coil on an iron ring. The needle on a second coil jumps, falls back to zero while the current still flows, and jumps the other way when he disconnects. Every generator and transformer is that ring.
Ep. 7 of How Humanity Discovered Electricity
#histsci
Ep. 7 of How Humanity Discovered Electricity
#histsci
1858. Two thousand volts are pushed into the first Atlantic cable to make the signal come through faster; within weeks the cable is dead. Ohm's law, ridiculed thirty years earlier, and William Thomson explain why.
Ep. 6 of How Humanity Discovered Electricity
#histsci #physics
Ep. 6 of How Humanity Discovered Electricity
#histsci #physics
The Law Nobody Wanted: Ohm, Kelvin and the Atlantic Cable | Electricity, Ep. 6
Ohm, Kelvin and the Atlantic cable: the law nobody wanted. Principia, 16 min.
youtu.be
September 18, 2026 at 8:19 AM
April 1820. During a lecture, Ørsted brings a compass next to a wire carrying current and the needle swings sideways: not towards the wire, not away from it, across it. Within weeks Ampère measures the force between two currents.
Ep. 5 of How Humanity Discovered Electricity
#histsci #physics
Ep. 5 of How Humanity Discovered Electricity
#histsci #physics
The Needle That Moved: Ørsted, Ampère and the Birth of Electromagnetism | Electricity, Ep. 5
Ørsted's needle, Ampère's forces and the birth of electromagnetism. Principia, 15 min.
youtu.be
September 18, 2026 at 6:24 AM
1800. Volta stacks discs of zinc and silver with brine-soaked cloth between them and gets, for the first time, a current that does not stop: the battery. It began with Galvani's frog legs twitching on a balcony in Bologna.
Ep. 4 of How Humanity Discovered Electricity
#histsci #physics
Ep. 4 of How Humanity Discovered Electricity
#histsci #physics
The Frog, the Battery and the First Electric Current | How Humanity Discovered Electricity, Ep. 4
Galvani's frog, Volta's pile and the first continuous current. Principia, 15 min.
youtu.be
September 18, 2026 at 4:28 AM
1785. Coulomb hangs a needle from a silver wire so fine that one degree of twist measures a force of a few billionths of a newton, and finds that the force between charges falls with the square of the distance. Franklin's rod came first.
Ep. 3 of How Humanity Discovered Electricity
#histsci
Ep. 3 of How Humanity Discovered Electricity
#histsci
Franklin, the Lightning Rod and Coulomb's Law | How Humanity Discovered Electricity, Ep. 3
Franklin, the lightning rod and Coulomb's torsion balance. Principia, 15 min.
youtu.be
September 18, 2026 at 2:32 AM
1785. Coulomb hangs a needle from a silver wire so fine that one degree of twist measures a force of a few billionths of a newton, and finds that the force between charges falls with the square of the distance. Franklin's rod came first.
Ep. 3 of How Humanity Discovered Electricity
#histsci
Ep. 3 of How Humanity Discovered Electricity
#histsci
1746. Pieter van Musschenbroek charges the water in a glass jar and touches the wire. The shock is so violent he writes that he would not take it again for the kingdom of France. The Leyden jar: the first device to store electricity.
Ep. 2 of How Humanity Discovered Electricity
#histsci #physics
Ep. 2 of How Humanity Discovered Electricity
#histsci #physics
The Jar That Nearly Killed Its Inventor (1746) | How Humanity Discovered Electricity, Ep. 2
The Leyden jar, from a Dutch physics cabinet to the shock felt across Europe. Principia, 15 min.
youtu.be
September 18, 2026 at 12:36 AM
1600. William Gilbert carves a lodestone into a sphere, moves a small needle over it and watches it dip exactly as compass needles dip at sea. The Earth is a magnet. Six hundred pages of experiments: De Magnete, the first modern book of physics.
Ep. 1 of How Humanity Discovered Electricity
#histsci
Ep. 1 of How Humanity Discovered Electricity
#histsci
The Earth Is a Magnet. One Man Proved It in 1600 | How Humanity Discovered Electricity, Ep. 1
Gilbert, the terrella and the first experimental book of physics. Principia, 13 min.
youtu.be
September 17, 2026 at 10:40 PM
1600. William Gilbert carves a lodestone into a sphere, moves a small needle over it and watches it dip exactly as compass needles dip at sea. The Earth is a magnet. Six hundred pages of experiments: De Magnete, the first modern book of physics.
Ep. 1 of How Humanity Discovered Electricity
#histsci
Ep. 1 of How Humanity Discovered Electricity
#histsci
1861. Maxwell works out how fast a disturbance travels through his model of empty space: 310,740 km/s, a number two Germans had measured five years earlier with a Leyden jar and a magnetic needle. Fizeau's speed of light: 314,858 km/s.
Ep. 8 of How Humanity Discovered Electricity
#histsci #physics
Ep. 8 of How Humanity Discovered Electricity
#histsci #physics
The Speed of Light Was Hiding in a Jar of Electricity (1861) | Electricity, Ep. 8
Maxwell, Weber and Kohlrausch, Fizeau and Hertz: how the speed of light turned up in a jar of electricity, and how an invisible wave was measured with a tape. Principia, 16 min.
youtu.be
September 17, 2026 at 10:36 PM