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Something I was just wondering about recently: If the earth's magnetic field (and other similar "passive" global effects) can be sensed enough to move a compass
by Razengan 4y ago
Something I was just wondering about recently: If the earth's magnetic field (and other similar "passive" global effects) can be sensed enough to move a compass needle, can it be used to power low-energy devices?
Like could we ever have always-on displays (like 0.00001 FPS, 10x10 pixels or whatever) or whatnot that are powered by the planetary magnetic field?
- thombat 4y agoSadly it's not enough to have a force; it needs to produce a motion (to perform work). Think of the analogy with a ball feeling gravity at the top of a hill: it has the potential to release energy but it remains unrealised until it starts rolling downhill. Once in motion energy can generated, say by coupling it to a dynamo, but once the ball is at rest at the bottom then even though it still feels gravitational attraction there is no power output.