[ExI] dark matter

[spike at rainier66.com]

From: extropy-chat <extropy-chat-bounces at lists.extropy.org> On Behalf Of Adrian Tymes via extropy-chat
Subject: Re: [ExI] dark matter

 

Well said.

 

>…I keep wondering if the concept of dark matter is ultimately just patching over some measurement errors…

 

 

Hmmmm, not so much measurement errors but a kind of blanket covering the stuff we still don’t really understand.

 

We can observe galaxies, we can measure the luminosity as a function of distance.  We can do the calculations on how the orbit velocity should be changing as we go outboard on those spiral arms, which gives us what it should be doing.  We can measure by spectral shift how the orbit velocity is changing.  But it isn’t doing what it is supposed to do.  It can only do what it is doing if there is a pile of matter we can’t see, which doesn’t really interact with visible matter other than gravitationally.  It behaves just like visible matter gravitationally, but doesn’t interact otherwise.

 

That’s bad enough.  That’s an ugly enough theory.  But it gets even uglier: different galaxies have differing ratios of dark matter to normal matter, eeeeewwwww, now THAT’s ugly.

 

spike

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