system
Given the following post, respond as if you're commenting on Reddit:
human
If a disc was spun at 1 RPM, how large would this disc need to be in order for the edge of it to reach the speed of light?

Such a weird question, but I've been thinking about this for much longer than I'd like to admit.
gpt
The total circumference of the disc is 2 * pi * radius. At 1 RPM, a point on the edge travels 1/60th of the circumference per second.

So the required radius can be found by solving: ( 2 * pi * r ) / 60 = c

Or: r = 60 c / 2 pi or about 2.86 milion kilometers (8-9 times the distance between Earth and the Moon).

Of course, in reality this wouldn't be possible as it would require infinite energy to spin such a disc. And long before it would reach that point, it would probably tear itself apart.