From: sichase@csa2.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Re: elem. questiona about ST o. Relaticity
Date: 6 Oct 1992 14:36 PST
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
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In article <1992Oct6.054217.3296@ncsu.edu>, elada@eos.ncsu.edu (ERIC  LADA) writes...

>	But,  What about the sk8er.  As he/she(though I've never seen a female
>	sk8er, and certainly not 1 named Bob), c's the world, the old ladies are
>	raopidly advanceing toward her/him.  So time should slow down for the 
>	old ladies.  How then can both frames of referece be valid?

Each person experiences time going at the "normal" rate.  And each person
see's the other's clock as going slower than theirs.  I recommend that 
you pick up Taylor and Wheeler's _SpaceTime Physics_, which can be understood
by anyone with background in trigonometry and the willingness to plow through
it and work out all the problems.

>	Nothing can travel faster than the speed of light whithout turning into 
>energy or going sdrawkcab(that's backwards speled sdrawkcab) in time(or some 
>other hocus-pocus like that) (right? I hope?)   

Things don't turn into "energy."  At best, two particles can mutually
annihilate into some photons, which travel, of course, at the speed of photons,
um... I mean light.

> Well Everythings relative(right?)

Wrong.  That's a very poor thing to remember as the only or best lesson
of special relativity.  It's not at all clear what it means, or if it is 
true.  Perhaps you mean that way things appear depends on your own local 
frame of reference.   That is certainly a true, though vague, statement.
But the important lesson of special relativity is that the laws of physics
are identical in all inertial frames, i.e., no matter what inertial frame
you do your observing from, the equations you will derive are exactly the same.

>so if Big Bird is shot out of a cannon at 299,984 m/s and the Cookie-moster is 
>joggingt in the opposite direction(trying 2 get rid of some of those fattening 
>cookies) going only 15 m/s, then as Big Bird sees it, the Cookie-monstor is 
>jogging at a whopping speed of 299,999 m/s. No problem.  But if the cooke 
>Were to throw one of his cookies forward, at 4m/s, the cooke would be going 
>faster that the speed-o-lite(as Big Bird sees it) How can that be or is it, or 
>somethin

This is not correct.  In special relativity, as a consequence of the fact
that the speed of light is the same in all inertial frames, the rule for
adding velocities is not the simple rule that you are using here.  I'll
spare you the equations, but point out that if you are watching a rocket
fly by at .9c, i.e., 90% of the speed of light, and someone on the rocket
fires a bullet forward at what he percieves to be .9c, you will not see
the bullet fly out at 1.8c.  The actual value is going to be .99c, i.e., 
close but not greater than the speed of light.  

I apologize for having explained so little.  What you require is more than
I can take the time to write right now.  Check out Taylor and Wheeler.  
You'll like it.

Good luck.

-Scott
--------------------
Scott I. Chase			"The question seems to be of such a character
SICHASE@CSA2.LBL.GOV		that if I should come to life after my death
				and some mathematician were to tell me that it
				had been definitely settled, I think I would
				immediately drop dead again."      - Vandiver
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