Re: relativity
- From: glhansen@xxxxxxxxxxxxxxxxxxxxx (Gregory L. Hansen)
- Date: Mon, 5 Sep 2005 02:56:06 +0000 (UTC)
In article <qfwSe.43451$884.1199886@xxxxxxxxxxxxxxxxxxxxx>,
Physitrex <physitrex<remove> wrote:
>Something I don't understand about relativity.
>
>Isnt' a conjecture of relativity that the laws of physics are the same for
>all observers ? I don't see how this could be the case.
>
>Suppose I'm an observer observing a physical event within a reference frame.
>
>Now suppose a different observer is placed in the reference frame, to
>observe exactly the same physical event.
>
>Won't both observers view what happened in a different manner, because they
>are different observers ?
>
>That is, unless the observers are identical (one and the same), the laws of
>physics won't appear to be identical. The physical event that I observed
>wont be identical to the physical event that another observer observed.
>
>Aren't the "laws of physics" the same only to the extent that the observers
>are identical ?
>
>Aren't we determining the physics based on the characteristics of the
>observers, if we use observation to glean knowledge about physics ?
>
>The universe is some sort of two dimensional hologram, because the observers
>see that way ?
The laws of physics are the same, not the numbers each observer gets on
his instruments. We can say F=ma without worrying about velocities.
An example, consider the Coulomb force. If there is a stationary source
charge and a test particle moving past it, it accelerates toward the
source charge. Boost the system so that the source charge is moving and
the test charge is still. It takes some time for information about the
instantaneous position of the source charge to reach the test particle
since the electromagnetic field moves at the speed of light. But the
test particle accelerated directly towards the source charge in the first
case, so it must still accelerate directly toward the source charge in
the second case. Which direction that is will depend on the observer,
but they can both relate the acceleration of one to the position of the
other. To make that true in the second case, the magnetic force must be
introduced. And by similar reasoning, a magnetic analog must exist for
any force whose field propagates at a finite rate. And by related
reasoning, any force that propagates at a finite rate must have an
associated radiation. That gives some idea of the role that assumption
will play-- if you assume the principle of relativity and a finite speed
of propagation, it would be a logical contradiction to suppose a force
without radiation or an analog to magnetism.
--
"You're not as dumb as you look. Or sound. Or our best testing
indicates." -- Monty Burns to Homer Simpson
.
- References:
- relativity
- From: Physitrex
- relativity
- Prev by Date: Re: GOD DAM letting the GANGS lord themselves over the refugees.
- Next by Date: Re: Artificial means to weaken hurricanes
- Previous by thread: Re: relativity
- Next by thread: Invariance As Part of Intersection Theory 3: Emmy Noether and Nathan Jacobson
- Index(es):
Relevant Pages
|
