system
Given the following post, respond as if you're commenting on Reddit:
human
if we ever run out of copper, for ecample for cables, what's our best bet in terms of price and availability?
gpt
Aluminum's always an option; plentiful, lightweight, excellent conductor, easily reused.  

That said, there are drawbacks.  Being softer than copper, handling aluminum wires means they're susceptible to breakage.  Aluminum also expands more when heated than copper does, and over time this can work wires out of connectors, causing arcs that can start fires.  Another issue is that while copper and aluminum both oxidize, copper oxide is conductive, whereas aluminum oxide isn't so much. This can change the properties of the transmission line.