Weird Science ...
This is a really strange and surprising effect.
When you drop an earth magnet through a copper pipe
it appears to slow down falling and spinning at a lower
rate than it should.
The falling magnet induces a current in the copper pipe
and by Lenz’s Law the current creates a magnetic field
that opposes the changing field of the falling magnet.
Thus, the magnet is "repelled" and falls more slowly.
Neodymium Magnet In FAT Copper Pipe
You did not understand, it is not a big deal.
Just get hyptnotized once more by this amazing
and weird physical phenomenon!
Regards