Gravity: Strength in Weakness: CSM

[Ivan Seeking]

For decades astronomers have been perplexed by so-called "dark matter" in our universe. It might be slightly more accurate to call dark matter "excess gravity," as what astronomer actually observe is gravitational force pulling stuff together where no matter appears to be present. This dark matter is currently measured to make up more than 90% of the mass of our universe, and has such intimate affects as holding our Milky Way galaxy together.

Is this extra gravity in fact coming from another brane, an entirely different universe? When we map the distribution of dark matter around our galaxy, are we in fact creating the first map of a parallel universe? Did the pull of gravity from another brane influence the way the structure of our universe formed and evolved? In the end it will all come down to gravity, and what its weakness tells us about the structure of reality.

Comments? How popular is this notion? I have read about this quite a few times...and Kaku often references this point.
http://www.csmonitor.com/2003/0924/p25s01-stss.html

 

[Nereid]

This will likely be the start of a quite lengthy thread.

Just to take one point:

This dark matter is currently measured to make up more than 90% of the mass of our universe

The first year's WMAP results (http://map.gsfc.nasa.gov/m_mm.html) suggest (cold) dark matter makes up only ~23%, with neutrinos (hot dark matter) another <1%.

 

[mathman]

Just to complete the picture, the remaining stuff (about 70%) is "dark energy" or something like it (Einstein's cosmological constant?), which is responsible for the observation that the expansion of the universe is accelerating.

 

[Nereid]

Oh, and just BTW, ~4% is made up of 'us stuff' (baryonic matter).

Not only is the Earth not the centre of the universe

Not only is the solar system ...

... {space to fill in your favourites}

... but everything that we can see, feel, touch, ... it's just a 'minor ingredient'.

Humility anyone?

 

[Horus]

In my theory (see "new theory of universe creation" in the theory development category) the excess gravity could be the matter taken into black holes since the dawn of time.

 

[ranyart]

I do so like the analogy of the water-skeeter!

 

[Nereid]

Is this extra gravity in fact coming from another brane, an entirely different universe?

The really cool thing about 'dark matter' is that we should soon start seeing some quite concrete predictions from various theories as to what it is. Even better, as the detritus of the Sag and Car dwarf galaxies becomes better mapped, as various 'dark matter telescopes' come on stream, as AMANDA II (and others) starts working, as LIGO (etc) settles down, GLAST is launched, ... there'll be at least an order of magnitude improvement in observational constraints over the next five years or so.

Now would be a good time for those with theories to start making firm predictions about what all these wonderful instruments and experiments will actually 'see'!

 

[ObsessiveMathsFreak]

Maybe we don't need dark matter. Maybe gravity just decreases as $$\frac{1}{r}$$ , instead of $$\frac{1}{r^2}$$

I can actually prove that this is so!

https://www.physicsforums.com/showthread.php?s=&threadid=474

Or maybe I'm just another crackpot.

 

[Nereid]

Continue this discussion in Theory Development?

OMF,

I had a look at your earlier posts, and feel that you ideas are worth discussing under Theory Development. If you'd care to start a thread there, I'll gladly comment on your idea, its match to observations, and pose some questions which you might like to consider.