system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how do electrical splices conduct the full current of the wire when only the surfaces of each wire are in contact?

Thinking of standard (US) solid wire (Romex). A typical splice using wire nuts just needs the sides of the two cylindrical wires to be touching, which is an incredibly small contact area. If the rest of the wire needs a certain cross sectional area to conduct the required current, how does that same amount of current transfer through that small contact area at the splice?
gpt
>If the rest of the wire needs a certain cross sectional area to conduct the required current

It needs that cross sectional area to support that current over long distances without heating up, and to support the occasional fault current.

The limited contact area of the wire nut does make it a bit hotter than the rest of the wire, but the rest of the wire also serves as a heatsink for the warmer connection keeping everything at a reasonable temperature

You can transfer crazy amounts of current through relatively small contact areas as long as the distance traveled is short and there's heatsinking.  A tiny 22 gauge wire can carry about 40 amps without going poof, it'll be hot but present and this is actually handy if you want to make something like a 20A fuse that should trip around 40A.  Any bond between 14 gauge wires is going to have wayyy more surface area than a 22 gauge wire and will only force the current to go a fraction of a millimeter before getting to the thicker part of the wire where it can flow with less resistance again.