Tag Archives: hydrogen atom

Secret of Scent Lies in Molecular Vibrations

Molecular vibrations, rather than molecular shape, give substances their distinct smell according to a new study by UCL scientists.

In a study designed to find out how smell is written into a molecule’s structure, scientists tested whether changing how a molecule vibrates on a nano-scale changes its smell.

Molecules are made of atoms connected by bonds. The arrangement of bonds and atoms defines the vibration of the molecule. Chemists can therefore identify molecules by their vibrations, using a spectroscope. (more…)

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Testing Einstein’s E=mc2 in Outer Space

UA physicist Andrei Lebed has stirred the physics community with an intriguing idea yet to be tested experimentally: The world’s most iconic equation, Albert Einstein’s E=mc2, may be correct or not depending on where you are in space.

With the first explosions of atomic bombs, the world became witness to one of the most important and consequential principles in physics: Energy and mass, fundamentally speaking, are the same thing and can, in fact, be converted into each other.

This was first demonstrated by Albert Einstein’s Theory of Special Relativity and famously expressed in his iconic equation, E=mc2, where E stands for energy, m for mass and c for the speed of light (squared). (more…)

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JILA Physicists Achieve Elusive ‘Evaporative Cooling’ of Molecules

Achieving a goal considered nearly impossible, JILA physicists have chilled a gas of molecules to very low temperatures by adapting the familiar process by which a hot cup of coffee cools.

JILA is a joint institute of the University of Colorado Boulder and the National Institute of Standards and Technology located on the CU-Boulder campus. (more…)

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First Stars, Galaxies Formed more Rapidly than Expected

Analysis of data from the National Science Foundation’s South Pole Telescope, for the first time, more precisely defines the period of cosmological evolution when the first stars and galaxies formed and gradually illuminated the universe. The data indicate that this period, called the epoch of reionization, was shorter than theorists speculated — and that it ended early.

“We find that the epoch of reionization lasted less than 500 million years and began when the universe was at least 250 million years old,” said Oliver Zahn, a postdoctoral fellow at the Berkeley Center for Cosmological Physics at the University of California, Berkeley, who led the study. “Before this measurement, scientists believed that reionization lasted 750 million years or longer, and had no evidence as to when reionization began.” (more…)

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A New Way of Looking at Photosystem II

Berkeley Lab and SLAC Researchers Study Key Protein Complex Crucial to Photosynthesis

Future prospects for clean, green, renewable energy may hinge upon our ability to mimic and improve upon photosynthesis – the process by which green plants, algae and some bacteria convert solar energy into electrochemical energy. An artificial version of photosynthesis, for example, could use sunlight to produce liquid fuels from nothing more than carbon dioxide and water. First, however, scientists need a better understanding of how a large complex of proteins, called photosystem II, is able to split water molecules into oxygen, electrons and hydrogen ions (protons). A new road to reaching this understanding has now been opened by an international team of researchers, led by scientists at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and SLAC National Accelerator Laboratory.

Using ultrafast, intensely bright pulses of X-rays from SLAC’s Linac Coherent Light Source (LCLS), the research team produced the first ever images at room temperature of microcrystals of the photosystem II complex. Previous imaging studies, using X-rays generated via synchrotron radiation sources, required cryogenic freezing, which alters the samples. Also, to catalyze its reactions, photosystem II relies upon an enzyme that contains a manganese-calcium cluster that is highly sensitive to radiation. With the high-intensity femtosecond X-ray pulses of the LCLS, the research team was able to record intact images of these clusters before the radiation destroyed them. (more…)

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Yale Research Offers New Way To See Inside Solids

Researchers at Yale University have developed a new way of seeing inside solid objects, including animal bones and tissues, potentially opening a vast array of dense materials to a new type of detailed internal inspection.

The technique, a novel kind of magnetic resonance imaging (MRI), creates three-dimensional images of hard and soft solids based on signals emitted by their phosphorus content. (more…)

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The First Spectroscopic Measurement of an Anti-Atom

*Berkeley Lab scientists helped build and operate the ALPHA antimatter trap at CERN, which has now probed the internal structure of the antihydrogen atom for the first time, taking the first step toward possible new insights into the difference between matter and antimatter*

The ALPHA collaboration at CERN in Geneva has scored another coup on the antimatter front by performing the first-ever spectroscopic measurements of the internal state of the antihydrogen atom. Their results are reported in a forthcoming issue of Nature and are now online.

Ordinary hydrogen atoms are the most plentiful in the universe, and also the simplest – so simple, in fact, that some of the most fundamental physical constants have been discovered by measuring the tiny energy shifts resulting from the magnetic and electric interactions of hydrogen’s proton nucleus with its single orbiting electron. (more…)

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