Rotating Disk Method to Attain Light Speed?

[aLeaf]

TL;DR

I thought of a disk rotating freely in space at 60 RPM, for example, as a way to move gross matter at and beyond the speed of light.
A point on the disk at a radius of 5/π meters would be moving at a speed of 10 m/sec, ∴ a point on the disk at a radius of (15x10⁷)/π meters should be moving at a speed of 3x10⁸ m/sec.

I thought of a disk rotating freely in space at 60 RPM, for example, as a way to move gross matter at and beyond the speed of light.

A point on the disk at a radius of 5/π meters would be moving at a speed of 10 m/sec, while a point on the disk at a radius of 50/π meters would be moving at a speed of 100 m/sec, right? So it would follow that a point on the disk at a radius of (15x10⁷)/π meters should be moving at a speed of 3x10⁸ m/sec.

I imagine that people who spend far more time cogitating on than I do would readily recognize where this construct fails. I look forward to reading your responses.

 

[Ibix]

The device distorts and disintegrates from internal stresses far before any part of it approaches lightspeed. If you posit arbitrarily strong materials you can get the rim arbitrarily close to lightspeed, but it will always disintegrate below lightspeed.

 

[aLeaf]

Disintegrate, as in atoms converting into photons? If so, then the disk itself would appear to us observing as a solid disk ringed by light...?

 

[Ibix]

Disintegrate, as in atoms converting into photons? If so, then the disk itself would appear to us observing as a solid disk ringed by light...?

No, just breaking apart, same as any other matter that you stress too much.

Make jelly and put it on a barstool. Spin the barstool and you'll get pelted with jelly fragments. Now replace the jelly with some other material. You have to spin the barstool faster the stronger the material is, but there is always a speed where the material will crack and fragments will fly off, and the speed of the rim at that point will always be below the speed of light.

 

[aLeaf]

Thank you for your replies.

 

[FactChecker]

The centrifugal force at the edge of the disk is proportional to the radius of the disk, which in this case is about 30,000 miles. Have you calculated that force? It might be very large. The disk would have to withstand that force.