Hans Christian Ørsted's Birthday
Next: August 14, 2027
The needle that twitched.
The story
Where it comes from
This Story marks the birthday of Hans Christian Ørsted, born on 14 August 1777 in Rudkøbing, on the Danish island of Langeland. The son of a pharmacist, he was apprenticed to his father at 13, then studied physics, philosophy and pharmacy at the University of Copenhagen. In the spring of 1820, during a lecture, he switched on a current in a wire and saw a compass needle beside it move. The audience barely noticed, but Ørsted had found the first link between electricity and magnetism, an effect he named electromagnetism.
How it's celebrated
There is no formal observance. The simplest way to mark the day is to repeat his experiment: lay a compass beside a wire, touch the wire's ends to a battery for a moment, and watch the needle swing. Ørsted's discovery set scientists across Europe experimenting, and their work on electricity and magnetism led, within decades, to the electric motor and the generator.
Did you know
- He published his results on 21 July 1820 in a short paper in Latin, sent to scientists and learned societies all over Europe.
- When the experiment was shown in Paris that September, André-Marie Ampère rushed home and worked non-stop for a week, and soon found that a coil of wire carrying a current can turn an iron bar into a magnet.
- As boys, he and his brother were taught by a wig-maker with little work and his wife, so they first learned to read and write in the wig-maker's native German.
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