What Happens to a Pole Spinning Near Light Speed?

AbyssalVortex
Messages
2
Reaction score
0
Ok. I got this today from looking at a crane spinning around.

What if you had an extremely long pole, huge order of magnitude, and you spin it. As you go outward, the velocity of the particles of the pole increase. As this velocity nears c, what happens to the pole as you keep going further away from the origin of rotation?
 
Physics news on Phys.org
Doesn't work. There is no such thing as a pole that is as rigid as you are thinking of. This question in one form or another is asked here every few months. Do a forum search for "rigid body"
 
Last edited:
What Phinds said. Also, there's an entry in the FAQ at the top of this forum: https://www.physicsforums.com/showthread.php?t=536289
 
Last edited by a moderator:
AbyssalVortex said:
As this velocity nears c, what happens to the pole as you keep going further away from the origin of rotation?
It breaks.
 
Ha, wow, can you say oblivious. Thanks phinds and Nugatory.
 
Thread 'Dirac's integral for the energy-momentum of the gravitational field'

Thread 'Dirac's integral for the energy-momentum of the gravitational field'

See Dirac's brief treatment of the energy-momentum pseudo-tensor in the attached picture. Dirac is presumably integrating eq. (31.2) over the 4D "hypercylinder" defined by ##T_1 \le x^0 \le T_2## and ##\mathbf{|x|} \le R##, where ##R## is sufficiently large to include all the matter-energy fields in the system. Then \begin{align} 0 &= \int_V \left[ ({t_\mu}^\nu + T_\mu^\nu)\sqrt{-g}\, \right]_{,\nu} d^4 x = \int_{\partial V} ({t_\mu}^\nu + T_\mu^\nu)\sqrt{-g} \, dS_\nu \nonumber\\ &= \left(...
View full post »

Thread 'Describing the Big Bang'

I started reading a National Geographic article related to the Big Bang. It starts these statements: Gazing up at the stars at night, it’s easy to imagine that space goes on forever. But cosmologists know that the universe actually has limits. First, their best models indicate that space and time had a beginning, a subatomic point called a singularity. This point of intense heat and density rapidly ballooned outward. My first reaction was that this is a layman's approximation to...
View full post »

Thread 'A sufficient condition for integrability of equation ##\nabla g=0##'

In Philippe G. Ciarlet's book 'An introduction to differential geometry', He gives the integrability conditions of the differential equations like this: $$ \partial_{i} F_{lj}=L^p_{ij} F_{lp},\,\,\,F_{ij}(x_0)=F^0_{ij}. $$ The integrability conditions for the existence of a global solution ##F_{lj}## is: $$ R^i_{jkl}\equiv\partial_k L^i_{jl}-\partial_l L^i_{jk}+L^h_{jl} L^i_{hk}-L^h_{jk} L^i_{hl}=0 $$ Then from the equation: $$\nabla_b e_a= \Gamma^c_{ab} e_c$$ Using cartesian basis ## e_I...
View full post »

Similar threads

I Speed of Light Could be Reached and Indeed even Exceeded
Replies
21
Views
2K
I What Happens When a Planet Nears the Speed of Light Near a Black Hole?
2
Replies
64
Views
5K
I Speed Difference of Time on Poles vs Equator of Earth and Other Planets
Replies
16
Views
4K
I One-Way Speed of Light: Is it Possible?
2
Replies
53
Views
6K
B Why is it impossible to go faster than the speed of light?
Replies
21
Views
3K
I What if particles are moving near light speed and one slows?
Replies
9
Views
1K
B Let me ask a thing about the Speed of Light
Replies
6
Views
1K
B Speed of light and this Accelerating Rocket scenario
Replies
45
Views
5K
B Proposed Experiment - Speed of Light
Replies
30
Views
3K
I Has anyone measured the speed of light in one direction?
Replies
45
Views
6K

Hot Threads

Recent Insights

Back
Top