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2Physics Quote:
"The quantum-mechanical behavior of light atoms plays an important role in shaping the physical and chemical properties of hydrogen-bonded liquids, such as water. Tunneling is a classic quantum effect in which a particle moves through a potential barrier despite classically lacking sufficient energy to transverse it. The tunneling of hydrogen atoms in condensed matter systems has been observed for translational motions through metals, anomalous proton diffusion in water phases, and in the rotation of methyl and ammonia groups ..."
Alexander I. Kolesnikov, George F. Reiter, Narayani Choudhury, Timothy R. Prisk, Eugene Mamontov, Andrey Podlesnyak, George Ehlers, Andrew G. Seel, David J. Wesolowski, Lawrence M. Anovitz
(Read Full Article: "Quantum Tunneling of Water in Ultra-Confinement"
)

Sunday, April 23, 2006

Proton-Electron Mass Ratio

Spectra of Hydrogen and Mercury

New measurements of starlights suggest that the ratio of the proton's mass to the electron's mass has increased by 0.002% over 12 billion years. The spectra of hydrogen gas as recorded in lab is compared with spectra of light coming from hydrogen clouds billions of light years away when the universe was in its youth.

Molecular hydrogen absorbs light of specific wavelengths, and the resulting spectrum of "absorption lines" uniquely identifies Hydrogen atom by the 'bar' code made up of such lines. The positions of the lines depend on the ratio of the mass of the proton to the mass of the electron. Of course, one needs to carefully take into account the effect of the expansion of the universe which shifts these lines from higher (ultraviolet) to lower (visible) frequency.

The researchers have reported in Physical Review Letters this week that the mass-ratio of proton and electron (the ratio is about 1836 and is denoted by the letter mu) has increased by about 20 parts per million over the past 12 billion years. The proton-to-electron mass ratio figures in setting the scale of the strong nuclear force.

More studies of spectra of Hydrogen gas from distant galaxies are needed to confirm whether the mass ratio has indeed changed.

Here is the link to the abstract of the paper in Physical Review Letters.

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