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Brown Dwarf With Water Clouds Tentatively Detected Just 7 Light-Years From Earth
sciencehabit (1205606) writes Astronomers have found signs of water ice clouds on an object just 7.3 light-years from Earth — less than twice the distance of Alpha Centauri. If confirmed, the discovery is the first sighting of water clouds beyond our solar system. The clouds shroud a Jupiter-sized object known as a brown dwarf and should yield insight into the nature of cool giant planets orbiting other suns.
No, the amount of missing matter is far to great to be contained in such small objects even if they were incredibly numerous.
Consider the entire mass of the asteroid belt is estimated to be only 4% of the Moon's mass, and the Moon's mass is only 1/81 of the Earth's.
Dark matter, meanwhile, is thought to have a total mass more than 5 times greater than that of normal matter.
Do what thou wilt shall be the whole of the Law
Logic fail. Dark matter can be explained by such small objects if they are incredibly numerous. It's just math: divide the missing mass by the mass of one brown dwarf to get the number needed. If you want to disprove the brown dwarf explanation you need to explain why the number that is needed contradicts something.
The hypothesized dark matter does not emit or absord any type of electromagnetic radiation, in other words it does not interfere with or react to light. Numerous small objects would. Also, and this is the most important bit in your logic fail fail, if you have enough small objects to account for five times the mass of the visible universe, you would have something five times more visible than the visible universe. Matter attracts other matter (which is why there is a dark matter hypothesis to begin with, something invisible attracts the visible) and such a copious amount of "small objects" would form larger objects. Which is how stars and planets form to begin with.
Exactly, we think of Jupiter as being huge but the Sun holds 98% of all the matter in our solar system. If the "missing mass" were normal cold matter, such a great quantity would effectively block the light of the stars we can see, astronomy would not exists because we wouldn't see anything except our own sun and moon.
Similar inane arguments were aimed at Newton, plenty of 15th century scholars thought that the fact a bird can fly disproved the theory of gravity. We still don't know what the hell gravity is (other than a property of matter) but we no longer question it's existence and have developed a very good understanding of how it behaves. Dark matter is harder to wrap one's head around because it's effects can not be observed in everyday human experience. However the effects are real and the tag scientists have given them is "dark matter".
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Its not a simple argument but if you look at:
http://en.wikipedia.org/wiki/D...
dark matter composed of bits of normal baryonic matter is not consistent with observations / simulations