- #1
ACG
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Hi! I'm sure this has been done before, but here goes.
Superman is flying through the vacuum of space and stumbles across a rod 100,000 kilometers long. This rod is of nonzero mass and is narrow enough for him to hold in his hand. It is infinitely rigid, with an infinitely high shear modulus. It can't be broken by anything and is perfectly uniform.
At any rate, Superman decides to get some exercise. He goes to the center of the rod and lifts the rod over his head. That's not enough exercise for him, however, as there's no gravity in space. So, he lifts the rod over his head and starts twirling it around at 60 rpm.
What happens to the rod? You may assume that Superman can impart an arbitrarily high (though finite) amount of angular momentum to the rod and that the rod never bends or breaks. The thing to keep in mind is that the ends of the rod are going to be whizzing around at 2*pi*50,000 km per second. This happens to be higher than c.
I was thinking of three cases:
1. The rod is infinitely rigid and can't bend or break.
2. The rod can bend but not break (think of it like rope). Presumably the rod bends, but how?
3. The rod can break but not bend (think of it like glass). Presumably the rod breaks, but how? And where?
Thanks in advance,
ACG
P.S. I know. Superman gets dizzy. But he's Superman. He doesn't throw up :)
Superman is flying through the vacuum of space and stumbles across a rod 100,000 kilometers long. This rod is of nonzero mass and is narrow enough for him to hold in his hand. It is infinitely rigid, with an infinitely high shear modulus. It can't be broken by anything and is perfectly uniform.
At any rate, Superman decides to get some exercise. He goes to the center of the rod and lifts the rod over his head. That's not enough exercise for him, however, as there's no gravity in space. So, he lifts the rod over his head and starts twirling it around at 60 rpm.
What happens to the rod? You may assume that Superman can impart an arbitrarily high (though finite) amount of angular momentum to the rod and that the rod never bends or breaks. The thing to keep in mind is that the ends of the rod are going to be whizzing around at 2*pi*50,000 km per second. This happens to be higher than c.
I was thinking of three cases:
1. The rod is infinitely rigid and can't bend or break.
2. The rod can bend but not break (think of it like rope). Presumably the rod bends, but how?
3. The rod can break but not bend (think of it like glass). Presumably the rod breaks, but how? And where?
Thanks in advance,
ACG
P.S. I know. Superman gets dizzy. But he's Superman. He doesn't throw up :)