What are our limitations on being able to spin a disc or rod to create a relativistically fast tip/edge speed?
My thoughts are you should be able to increase the radius of the spinning object to offset the growing tensile strain as you increase RPMs, would this increase be so massive that it would not feasible to build?
I was surprised that I couldn't find experiments doing something like this for the purpose of testing special relativity, the highest speed I could find for a massive spinning object was for a fly-wheel with and edge speed going a few Mach (still impressive, I just must be missing something as to why we haven't done faster).