The heaviest element yet?
Nature News: Could super-heavy elements be lurking in plain sight? One group of physicists says that they are, and claims to have seen the heaviest element yet found hiding amongst thorium atoms.
Some theories predict that some super-heavy elements might be unusually stable, thanks to a 'magic' number of protons and neutrons, and so could be lying around in nature. Several groups are now engaged in searches for them. If confirmed, this would be the first report of finding one.
But the team's claims, which are not peer-reviewed, are being heavily criticised by other physicists, who fear that their technique is flawed. "I have grave doubts," says Rolf-Dietmar Herzberg, a nuclear physicist at the University of Liverpool, UK.
Some theories predict that some super-heavy elements might be unusually stable, thanks to a 'magic' number of protons and neutrons, and so could be lying around in nature. Several groups are now engaged in searches for them. If confirmed, this would be the first report of finding one.
But the team's claims, which are not peer-reviewed, are being heavily criticised by other physicists, who fear that their technique is flawed. "I have grave doubts," says Rolf-Dietmar Herzberg, a nuclear physicist at the University of Liverpool, UK.
Comments
Other forms of even more exotic atoms would be a stable bound state of a positron and an electron referred to as positronium. Such an atom would entail the bound state of a positron and an electron wherein these particles would be far enough apart yet bound by the electric force so as not to undergo pair annihilation. Such a substance would make excellent fuel that would have the greatest mass specific energy density of any known fuel, a fact that would enable its use as an excellent rocket fuel or power source for electro-dynamically powered, high gamma factor capable, relativistic manned interstellar spacecraft. Such craft could in theory operate as photon rockets, ion rockets, electron rockets,electro-plasma-hydrodynamic-drive, and matter/antimatter reaction catalyzed fusion rockets that extract fusion fuels from the interstellar medium. Thus a large portion of the Milky Way could be opened up for human space exploration during one human familial generation ship time.
Another form of denser matter/antimatter substance would involve a bound state of a proton and an anti-proton as an analogue to positronium. Because the width of the apparent cross-sectional area of particle is inversely related to its mass, so-called protonium might have a density roughly a billion times greater than positronium according to some estimates.
A still more dense form of atom might involve strangelets which would in theory be composed of roughly equal numbers of up, down, and strange quarks. An matter/antimatter version of strangelet and anti-strangelet material might be an even denser analogue than protonium.
The Caveat in all of the above speculation is the binding of the matter and antimatter particles in a stable manner. This would entail precisely coordinating the approach of such particles to each other so that they enter any possible stable bound states without effective coulombic force based collision. The company Positronics Research LLC is a research firm located in New Mexico, pursuing antimatter storage and utilization for high energy applications in propulsion and medical arenas. They supposedly have or are working to develop small numbers of sample stable positronium atoms.
Posted by: James M. Essig | May 17, 2008 10:54 PM