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From: ins_akaa@jhunix.UUCP (Kenneth Adam Arromdee)
Newsgroups: net.startrek
Subject: Re: New discussion
Message-ID: <1079@jhunix.UUCP>
Date: Thu, 31-Oct-85 17:50:05 EST
Article-I.D.: jhunix.1079
Posted: Thu Oct 31 17:50:05 1985
Date-Received: Sun, 3-Nov-85 14:16:28 EST
References: <353@uw-june.UUCP> <8500013@orstcs.UUCP> <198@ur-tut.UUCP>
Reply-To: ins_akaa@jhunix.ARPA (Kenneth Adam Arromdee)
Distribution: net
Organization: Johns Hopkins Univ. Computing Ctr.
Lines: 33

In article <198@ur-tut.UUCP> scco@ur-tut.UUCP (Sean Colbath) writes:
>In article <8500013@orstcs.UUCP> jamesp@orstcs.UUCP (jamesp) writes:
>>This is called "Cherenkov Radiation,"  and happens all the time.  Often a
>>subatomic particle is moving faster than the speed of light in a medium (for
>>example, the speed of light in water is much less than the speed of light in a
>>vacuum -- ever seen a picture of a nuclear reactor with that beautiful
>>sky-blue "radioactive" glow?  That's caused by lots of alpha and beta
>>particles ripping through the water faster than the speed of light.)
>
>WHAT???  The speed of light in water is much less than the speed of light 
>in a vacuum????  AAAUUUGHH!!  Einstein just rolled over!  I always thought:
>'The speed of light is the same for all observers, no matter what his 
>frame of reference'...  If what you say is true, then all kinds of phenomena
>would open up simply by exceeding this 'slower' speed in water...  Eek! 

Equations in physics that refer to "the speed of light" really mean "the speed
of light in a vacuum".  This includes the statement about frames of reference.
Two observers in different frames of reference will see light travel at the
same speed IN A VACUUM.  The "in a vacuum" is understood.

No "all kinds of phenomena" would open up by exceeding the speed of light in
water, because the equations describing behavior of objects near the speed
of light also really mean "in a vacuum".  Unusual (i.e. impossible) phenomena
would only happen if you exceeded this higher speed.
-- 
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If you know the alphabet up to 'k', you can teach it up to 'k'.

Kenneth Arromdee
BITNET: G46I4701 at JHUVM and INS_AKAA at JHUVMS
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