82549Re: quantum darwin?
- Mar 27, 2005
----- Original Message -----
From: "Doug Pensinger" <brighto@...>
To: "Killer Bs Discussion" <brin-l@...>
Sent: Sunday, March 27, 2005 10:50 PM
Subject: Re: quantum darwin?
> Dan wrote:
> So if I had a rod that reached from here to the moon and was able to
> manipulate it in the same manner that that beam of light is manipulated,
> has the tip of that rod exceeded the speed of light?
Yes. But, if you work out the forces you would find that the strength of
the rod would have to approach infinity as the speed of the tip approaches
the speed of light because the mass of the tip would approach infinity as
the tip approaches the speed of light. The torque that needs to be applied
also approaches infinity.
This can be worked out simplest in the reference frame of the earth's
center of mass. Since all reference frames are equally valid for doing
physics, I'm allowed to pick the simplest.
So, the answer really is that, if you had such a rod, you couldn't do that.
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