When the computer wants a bit to be a 1, it pops it down. When it wants it to be a 0, it pops it up.
If it were like a punch card, it couldn’t be rewritten as writing to it would permanently damage the disc. A CD-RW is basically a microscopic punch card though, because the laser actually burns away material to write the data to the CD.
More like microscopic fidget bubble poppers.
When the computer wants a bit to be a 1, it pops it down. When it wants it to be a 0, it pops it up.
If it were like a punch card, it couldn’t be rewritten as writing to it would permanently damage the disc. A CD-RW is basically a microscopic punch card though, because the laser actually burns away material to write the data to the CD.
They work through electron tunneling through a semiconductor, so something does go through them like an old punch card reader