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Examining the Expected Effects of Dark Matter On the Solar System
First time accepted submitter LiavK writes "Ethan Siegel recently wrote a great post for ScienceBlogs discussing the expected total mass of dark matter in the solar system. As far as we can tell, dark matter only interacts weakly, via gravity, both with itself and normal matter. So, it can't collide with itself, meaning that it has no way of getting hotter and radiating away energy and momentum. This means that it remains a diffuse mess, with a density that is ridiculously low, to the point where detecting its local effects is likely to remain... challenging for the foreseeable future."
Or you could say space has a property of localized time. Which means time doesn't scale or progress uniformly throughout the universe. If you've got enough gravity, it's going to make things appear even more massive then they are because of time dilation. The relationship of gravity vs. time also means c should be treated as a coefficient rather than a constant. (The effective value of c still remains fixed, but that's because relationship of distance vs. time has both parts as variables. Time effectively rescales itself at higher energies to maintain c for a given distance traveled by a particle, but if you don't account for that, the extra momentum approaching or exceeding c looks like a gain in mass.)
Somebody with better math skills than myself could probably re-jigger Special Relativity in this regard and account for missing mass. It may even show a cumulative effect with gravitational time dilation when you have a system of multiple orbiting objects. But you might also have to toss the idea of a "Big Bang" out the window. (Makes "age" of things in the universe fairly irrelevant when a localized second is defined by the gravitational or acceleration field it's being measured under. Not to mention under certain conditions the typical light-year measuring stick astronomers like to use will also look about as uniform as a funhouse mirror. The funny-sounding Dr. Who sci-fi explanation of time being "Wibbly wobbly" may have some real logic to it.)
Of course it sounds nutty, because it opens up a lot of loopholes. Probably explains why Einstein was uncomfortable with some things, even if it provided the template for a more accurate model than some later revisions.
This is probably a dumb question, but I've been wondering about it for something like a decade, and I never see it referenced (even to debunk it) in legitimate science discussions.
A mysterious effect which looks like matter, but is invisible except for its gravitational effect. A second mysterious effect which causes the rate-of-expansion of the universe to increase.
I grow more and more skeptical of string theory and its relations every year, but the first of those definitely sounds to me like matter that's in another brane. The second one seems (to my non-physicist mind) like it could also be explained by the same thing, just a different set of matter in a different position relative to the first.
If our universe really is a 3D brane in a hyperdimensional space with others, isn't this exactly the sort of thing we'd expect to see? Further, wouldn't we see related effects like neutron stars unexpectedly flashing into black holes when they come into close-enough contact with dense clumps of matter in adjacent branes (IOW, when there's not enough observed mass in our own to explain the change to a black hole)?
"...always new atoms but always doing the same dance, remembering what the dance was yesterday." -Richard Feynman
Don't make the mistake of thinking there was just one ether theory. There were lots of them, many quite compatible with special relativity. Quite a few that sound like 1890s versions of quantum electrodynamics.