system
Given the following post, respond as if you're commenting on Reddit:
human
Two of the same type of metals will bond together in space?

Just got a interesting Snapple fact! Says that if two of the same type of metals touch in space they will bond together permanently! Why does this happen? And when it does how fast does it occur?
gpt
It is called cold welding or vacuum welding.  Richard Feynman explains it as such:
"The reason for this unexpected behavior is that when the atoms in contact are all of the same kind, there is no way for the atoms to “know” that they are in different pieces of copper. When there are other atoms, in the oxides and greases and more complicated thin surface layers of contaminants in between, the atoms “know” when they are not on the same part."