13 DEC 2011 by ideonexus
The Creation of Carbon in Stars
The first step occurs when older stars start to accumulate helium, which is produced when two hydrogen nuclei collide and fuse with each other. This fusion is how stars create the energy that warms us. Two helium atoms can in turn collide to form beryllium, an atom whose nucleus contains four protons. Once beryllium is formed, it could in principle fuse with a third helium nucleus to form carbon. But that doesn't happen, because the isotope of beryllium that is formed decays almost immediatel...
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Requires a very delicate balance of natural laws. If the strong nuclear force were to change by as little as 0.5 percent, there would be no carbon or oxygen in the Universe.
30 JAN 2011 by ideonexus
How to Disguise a Helium Atom as a Hydrogen Atom
Donald Fleming of the University of British Columbia in Vancouver, Canada, and colleagues managed to disguise a helium atom as a hydrogen atom byreplacing one of its orbiting electrons with a muon, which is far heavier than an electron.
Because it is so heavy, the muon sits 200 times closer to the helium nucleus than the electron it replaces and cancels out one of the nucleus's positive charges. The remaining electron then behaves as if it were orbiting a nucleus with just one positive ch...
1 Neat experiment that allowed a Helium atom to act like a hydrogen one.
