Let's say that instead of a lightbulb, we have a morse code wire with two stations, one on Earth (and yes, let's ignore that Earth is rotating and constantly moving) and one near Alfa Centauri. If an operator starts punching codes, will the other end immediately receive them?

[–] blackbelt352@lemmy.world 2 points 10 months ago (1 children)

Oh apologies with a missed detail. The battery+switch and the lightbulb are 1 meter apart and are connected by a wire that is 1 lightyear long.

Assuming that electricity is only carried inside the wire (like our conventional understanding and models expect), yes it does break the speed of light but electricity doesn't actually travel inside the wire but in the electric field around the wire, which gives the wire near the battery to affect the wire near the light and create a tiny voltage difference, thereby nearly instantly lighting the lightbulb that reaches max brightness on any voltage differential.

[–] elbarto777@lemmy.world 2 points 10 months ago (1 children)

Thanks! I think I'm starting to understand it now. When the switch is flicked, the field starts doing its thing, whatever that is, and thus electricity begins to flow "in the vicinity" of the lightbulb and the switch. That's why the lightbulb turns on.

Having said that, if there was another lightbulb connected at the opposite extreme of the circuit, say, half a lightyear away, then that lightbulb wouldn't immediately turn on. It will turn on eventually, but like, six months later. Would that be correct?

[–] blackbelt352@lemmy.world 2 points 10 months ago (1 children)

Yup that's it

[–] elbarto777@lemmy.world 2 points 10 months ago

Wild! Thanks!