Halo of hot gas found around the Milky Way

Dear Yousuf Khan:

On Monday, October 1, 2012 6:33:57 AM UTC-7, Yousuf Khan wrote:
....
Well if Dark Energy is just the Cosmological
Constant, then the question would be why is
there any Cosmological Constant at all, why
it's this value. Einstein just put it in as
an afterthought.

It was in originally, with a value that described Universal expansion... just the wrong value. Einstein then put in a specific value intentionally, to achieve a static Universe (his "biggest blunder"). We have since allowed observation to drive what value it must be, based on our assumed amounts of baryonic and Dark matter.

Science does not do "why" questions, but I'll take a stab at an answer: This constant describes a default / average / global value for net production of entropy via production of additional intermediate states. It is not a single value over all of visible recorded time, but changes globally between epochs (initial inflation, near static, acceleration). Were it some sort of Energy, where did the energy come-from / go-to? Of course, gravitation is not a force, so it does not *have* to be energy. What makes it a given value, at a given epoch... *that* is the question.

David A. Smith

In article ,
Yousuf Khan writes:
Well, until now it was invisible to our various scopes, but now we find
it's visible in some special regions of the X-ray range, thus
pseudo-WIMPs, i.e. mostly not interacting with light, thus the
electromagnetic field.

The matter in question is mostly protons and electrons, or at least
there's no reason to believe otherwise. A small fraction has to be
oxygen ions.

You can make up your own terms if you like, but don't expect anyone
else to understand them. I've never seen the term "pseudo-WIMPS"
before, but I wouldn't expect it to refer to normal matter. WIMPS is
a common term that has a specific meaning; among other things, it
means "not interacting by the electromagnetic force." Protons,
electrons, and oxygen ions are not WIMPS.

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