Re: Dark matter/energy - is it real?

Shawn Wilson wrote:
"Erik Max Francis" <max@xxxxxxxxxxx> wrote in message
news:ceKdnUQzxdHJt63ZnZ2dnUVZ_uWdnZ2d@xxxxxxxxxxxxxxxx
Dark matter is apparently supposed to be some form of non-luminescent
matter, but what is dark energy supposed to be?

The existence of dark matter is inferred by, among other things, looking
at galactic rotation curves.

All that tells us is that our theories of how fast they should spin are
wrong, it does *not* tell us why. Dark matter is a shim to make existing
theories work, nothing more. There are theories that explain the variation
without dark matter.

We can see galaxies spinning, and we can
measure how fast the matter in them is moving (due to Doppler shift). By
doing this, we see that they're moving much faster than they would be if
only the glowing matter we see were there. That is, if our theories of
gravity are anything like correct, there must be a lot of matter there we
can't see.

This really isn't all that surprising; the fundamental concept of dark
matter is not all that mysterious. Most of the matter around you consists
of dark matter: It does not emit its own light.

That is not what dark matter is.

Dark matter is not just matter that doesn't glow, it's entirely different.

Dark matter is non-baryonic. Which is to say it isn't made of baryons.
Since protons and neutrons are baryons, dark matter isn't made up of protons
and neutrons.

We know it's non baryonic because we know approximately how many baryons the
big bang made. For baryonic matter to be the missing mass there would have
to be about ten times as many as the theory predicts.

That leaves another form of matter. But there's a huge hole in the theory
of dark matter- if the universe is mostly made up of it, where is it? Why
don't we see any on Earth? Why do no known physical processes create it?
It's not that it's undetectible- we would notice that energy was missing
from reactions (which is how we found the neutrino).

Dark matter, if it exists and judging by the ways galaxies rotate, isn't
distributed right either. It would have to itself be unaffected by gravity
while affecting non-dark matter, but organize itself into halos around
galaxies for some unknown reason.

So the dark matter theory is still extremely problematic... Hm.

So far they are extremely good theories,

Except for the bits they don't explain, which means everything is a good
theory.

:-)

Newton works but is wrong too. All we really know is that our theories work
on a planetary scale, but not on a galactic scale.

So you agree that there are still quantum leaps to be made for our
inadequate standard models. Looking at my briefly stated theory in
another post in this thread, do you think it might have potential?

- Tue

.

Relevant Pages

  • Re: Explanation of Ring Shape Dark Matter
    ... The above video is a narration about the finding of dark matter formed ... Any folks know any possible explanation of the ring ... CAN GALACTIC HALOS BE MADE OF BARYONS? ...
    (sci.physics.research)
  • Re: Explanation of Ring Shape Dark Matter
    ... Any folks know any possible explanation of the ring ... CAN GALACTIC HALOS BE MADE OF BARYONS? ... This reference provides logic why dark matter halos ... How the dark energy fluid media appears to decelerate why not ...
    (sci.physics.research)
  • Re: Dark matter/energy - is it real?
    ... The existence of dark matter is inferred by, among other things, looking ... Which is to say it isn't made of baryons. ... It's not that it's undetectible- we would notice that energy was missing ... It would have to itself be unaffected by gravity ...
    (rec.arts.sf.science)
  • Scientists elucidate the origin of the darkest galaxies in the universe (Forwarded)
    ... Scientists elucidate the origin of the darkest galaxies in the universe ... Ghostly galaxies composed almost entirely of dark matter speckle the ... Now, Stelios Kazantzidis, a researcher at Stanford University's Kavli ... Using supercomputers to create novel simulations of galaxy formation, ...
    (sci.astro)
  • New analysis puts dark matter back into elliptical galaxies (Forwarded)
    ... This theory faced a challenge in 2003, when a team of astronomers reported a surprising absence of dark matter in elliptical galaxies. ... But a new analysis published in the September 29 issue of the journal Nature provides an explanation for the earlier observations that fits comfortably with the standard theory and puts the dark matter back into elliptical galaxies. ... "A dearth of dark matter in elliptical galaxies is especially puzzling in the context of the standard theory of galaxy formation, which assumes that ellipticals originate from mergers of disk galaxies," added Avishai Dekel, professor of physics at the Hebrew University of Jerusalem and first author of the Nature paper. ... Whereas spiral galaxies are dominated by flattened, rotating disks of stars and gas, elliptical galaxies are round, smooth collections of stars. ...
    (sci.astro)