It’s 2018 and I still have no clue how CDs work. It’s a shiny disc, how do they get data on that, let alone that much?? Magic
Like a vinyl disc, where a physical groove is marked into the vinyl, a laser marks the ink of a CD in a similar manner.
A laser (your disc drive) can then look at the pattern in the ink and understand it.
There’s no grooves on a CD tho???
They’re just really tiny, hence the laser. The smaller grooves means that more info can fit on a disc of the same size.
Man how the fuck did they figure out how to make that
Fun fact: This is why a scratched CD no longer plays correctly. The grooves are actually a form of binary that can be read – when it becomes scratched, the grooves are destroyed and the information on that section is lost. This is also why leaving CDs in the heat is bad, as it melts the grooves.
The ‘grooves’ are actually imprinted on an extremely thin sheet of aluminum (or, occasionally, gold or another material, to some extent for better reflectivity but mostly I think because people really like gold) that is encased in clear plastic to protect it. Sort of like lamination. However, the aluminum disc is not centered within the plastic; there is much thicker layer of protection for the ‘playing’ side of a CD (the shiny side that usually faces down in a player) than the opposing label side. Because of this, it takes a much deeper scratch to damage the aluminum on the playing side than on the label side; the shallowest nick on the label will often cut right through the aluminum and destroy a CD.
funeral-biscuit 