When playing tetris today, I started wondering where the blocks which disappear, go to. They seem to vanish into the great nothing, but that's not true.

Fact is: they go to where the new blocks come from. Some company receives all the blocks from the vanished lines, sorts them out and makes new blocks of the parts.

It's called the Tetris Block Renewal Company, it has several installations all over the world and it's completely run by volunteers.

The block parts fall onto a conveyor belt through an enormous funnel, the parts then get sorted out and put on different assembly lines, one for each color/kind of block.
They get put together there again and then they disappear again into a mysterious hole in the wall, after which they appear in tetris games all over the world.

Now you all know!

that does make a lot of sense. so it ain't just a game then?

It sure is a game. But it's also a job for the volunteers.