Subscribe:
RSS feed
"Everything should be as simple as it is, but not simpler", Albert Einstein
Browsing All Posts filed under »ATOMIC PHYSICS«
New insights into what triggers lightning
Cosmic rays interacting with water droplets within thunderclouds could play an important role in initiating lightning strikes. That is the claim of researchers in Russia, who have studied the radio signals emitted during thousands of lightning strikes. The work could provide new insights into how and why lightning occurs in the first place. Although most […]
A Boy And His Atom: The World’s Smallest Movie
May 1, 2013
You’re about to see the movie that holds the Guinness World Records™ record for the World’s Smallest Stop-Motion Film (see how it was made at http://youtu.be/xA4QWwaweWA). The ability to move single atoms — the smallest particles of any element in the universe — is crucial to IBM’s research in the field of atomic memory. But even […]
Τhe Shrinking Proton: Particle Is Smaller Than Thought
April 14, 2013
How many protons can dance on the head of a pin? The answer is nowhere near as straightforward as one may think — and it might offer new insights into one of the most well-tested theories in physics. An international team of scientists recently tried to find out the actual size of a proton, one […]
Giant Milky Way bubbles blown by black hole merger
March 8, 2013
A tiny galaxy that collided with the Milky Way spawned two huge bubbles of high-energy particles that now tower over the centre of our galaxy. This new model for the birth of the mysterious bubbles also explains discrepancies in the ages of stars at the galactic middle. In 2010, sky maps made by NASA’s Fermi […]
Transforming noise into mechanical energy at nanometric level
November 12, 2012
Driving a Macroscopic Oscillator with the Stochastic Motion of a Hydrogen Molecule Christian Lotze, Martina Corso, Katharina J. Franke, Felix von Oppen, Jose Ignacio Pascual Energy harvesting from noise is a paradigm proposed by the theory of stochastic resonances. We demonstrate that the random switching of a hydrogen (H2) molecule can drive the oscillation of […]
Nov. 8, 1895: Roentgen Stumbles Upon X-Rays
November 8, 2012
Roentgen was conducting experiments with a Crookes tube — basically a glass gas bulb that gives off fluorescent light when a high-voltage current is passed through it — when he noticed that the beam turned a screen 9 feet away a greenish fluorescent color, despite the tube being shielded by heavy black cardboard. Roentgen concluded, correctly, […]
Building the Smallest Possible Ice Crystal
September 21, 2012
It may sound like a Zen koan, but it’s a serious scientific question: How many molecules of water does it take to make the smallest possible ice crystal? Because crystals are defined by a repeated, three-dimensional arrangement of molecules, you can’t necessarily take any small group of bonded-together molecules and call them a crystal. That’s […]
Ultracold fermions simulate spin–orbit coupling
September 5, 2012
Two independent groups of physicists are the first to use ultracold fermionic atoms to simulate “spin–orbit coupling” – an interaction that plays an important role in the electronic properties of solid materials. Both experiments were done by firing laser beams at the atoms, which caused their momentum to change by an amount that depends on […]
Quantum dynamics of the avian compass
August 22, 2012
Zachary B. Walters The ability of migratory birds to orient relative to the Earth’s magnetic field is believed to involve a coherent superposition of two spin states of a radical electron pair. However, the mechanism by which this coherence can be maintained in the face of strong interactions with the cellular environment has remained unclear. […]
A Matterwave Transistor Oscillator
August 20, 2012
Seth C. Caliga, Cameron J. E. Straatsma, Alex A. Zozulya, Dana Z. Anderson A triple-well atomtronic transistor combined with forced RF evaporation is used to realize a driven matterwave oscillator circuit. The transistor is implemented using a metalized compound glass and silicon substrate. On-chip and external currents produce a cigar-shaped magnetic trap, which is divided […]
Magic Angle
July 27, 2012
by Glenn Roberts Jr. The magic angle is all about mathematics, not hocus pocus, but it can work wonders in gathering useful data in scientific experiments and in medical imaging, too. John Bozek, an instrument scientist at SLAC’s Linac Coherent Light Source, said the angle, which measures about 54.7 degrees, is important for a range […]
New chemical bonds possible in extreme magnetic fields
July 21, 2012
In the extreme magnetic fields of white dwarves and neutron stars, a third type of chemical bonding can occur. That is the finding of theoretical chemists in Norway, who have used computer simulations to show that as-yet-unseen molecules could form in magnetic fields much higher than those created here on Earth. High-school chemistry students are […]
Computer that could outlive the universe a step closer
July 19, 2012
The heat-death of the universe need not bring an end to the computing age. A strange device known as a time crystal can theoretically continue to work as a computer even after the universe cools. A new blueprint for such a time crystal brings its construction a step closer. Ordinary crystals are three-dimensional objects whose […]
Physicists Identify New Quantum State
July 3, 2012
Strength in Numbers: Physicists Identify New Quantum State Allowing Three — But Not Two — Atoms to Stick Together A Kansas State University-led quantum mechanics study has discovered a new bound state in atoms that may help scientists better understand matter and its composition. The yet-unnamed bound state, which the physicists simply refer to as […]
From Photons to Atoms – The Electromagnetic Nature of Matter
June 16, 2012
Daniele Funaro Motivated by a revision of the classical equations of electromagnetism that allow for the inclusion of solitary waves in the solution space, the material collected in these notes examine the consequences of adopting the modified model in the description of atomic structures. The possibility of handling “photons” in a deterministic way opens indeed […]
Performance of a 229 Thorium solid-state nuclear clock
April 21, 2012
G. A. Kazakov, A. N. Litvinov, V. I. Romanenko, L. P. Yatsenko, A. V. Romanenko, M. Schreitl, G. Winkler, T. Schumm The 7.8 eV nuclear isomer transition in 229-Thorium has been suggested as an etalon transition in a new type of optical frequency standard. Here we discuss the construction of a “solid-state nuclear clock” from […]
Can GPS find variations in Planck’s constant?
March 28, 2012
Read more: physicsworld.com/cws/article/news/49135 Global Positioning System Test of the Local Position Invariance of Planck’s Constant J. Kentosh and M. Mohageg Phys. Rev. Lett. 108, 110801 (2012) Published March 15, 2012 Pinpointing Planck’s Constant with GPS GPS is helping drivers find their way and parents track their kids and pets. But now a pair of researchers—reporting in Physical Review Letters—has used […]
A Determination of the Fine Structure Constant …
March 17, 2012
… using Precision Measurements of Helium Fine Structure Marc Smiciklas Spectroscopic measurements of the helium atom are performed to high precision using an atomic beam apparatus and electro-optic laser techniques. These measurements, in addition to serving as a test of helium theory, also provide a new determination of the fine structure constant α. An apparatus […]
The First Measurements Of The Antihydrogen Spectrum
March 8, 2012
A New Result From ALPHA Once you’ve trapped antihydrogen what do you do? You measure it! That’s just what we’ve done. Published in Nature, we report the first resonant quantum transitions in antihydrogen atoms. We’ve used microwave radiation to change the internal state of the atom, from one which can be kept in our trap, […]
Scientists image the charge distribution within a single molecule for the first time
February 27, 2012
IBM scientists were able to measure for the first time how charge is distributed within a single molecule. This achievement will enable fundamental scientific insights into single-molecule switching and bond formation between atoms and molecules. Furthermore, it introduces the possibility of imaging the charge distribution within functional molecular structures, which hold great promise for future […]
Single atom transistor gets precise position on chip
February 19, 2012
In a remarkable feat of micro-engineering, UNSW physicists have created a working transistor consisting of a single atom placed precisely in a silicon crystal. http://youtu.be/ue4z9lB5ZHg Read more here
Rutherford, Radioactivity, and the Atomic Nucleus
February 7, 2012
Helge Kragh Modern atomic and nuclear physics took its start in the early part of the twentieth century, to a large extent based upon experimental investigations of radioactive phenomena. Foremost among the pioneers of the new kind of physics was Ernest Rutherford, who made fundamental contributions to the structure of matter for more than three […]
Anti-matter atoms to address anti-gravity question
January 27, 2012
The question of whether normal matter’s shadowy counterpart anti-matter exerts a kind of “anti-gravity” is set to be answered, according to a new report. Normal matter attracts all other matter in the Universe, but it remains unclear if anti-matter attracts or repels it. A team reporting in Physics Review Letters says it has prepared stable pairs of […]
Rice lab mimics Jupiter’s Trojan asteroids inside a single atom
January 24, 2012
Rice University physicists have built an accurate model of part of the solar system inside a single atom. In a new paper in Physical Review Letters, Rice’s team and collaborators from Oak Ridge National Laboratory and the Vienna University of Technology showed they could make an electron orbit the atomic nucleus in the same way […]
Landmarks–Millikan Measures the Electron’s Charge
January 23, 2012
The Millikan oil drop experiment, published in final form in 1913, demonstrated that charge comes in discrete chunks and was a bridge between classical electromagnetism and modern quantum physics. Researchers now routinely isolate single electrons in quantum dots, but a century ago the state-of-the-art charge-trapping device was a droplet of clock oil. Robert Millikan’s oil […]
Carbon Dating with Lasers
January 3, 2012
Phys. Rev. Lett. 107, 270802 (2011) [4 pages] Molecular Gas Sensing Below Parts Per Trillion: Radiocarbon-Dioxide Optical Detection I. Galli, S. Bartalini, S. Borri, P. Cancio*, D. Mazzotti, P. De Natale, and G. Giusfredi Istituto Nazionale di Ottica-CNR (INO-CNR) and European Laboratory for Non-Linear Spectroscopy (LENS) Via N. Carrara 1, I-50019 Sesto Fiorentino, Italy Radiocarbon (14C) concentrations at a 43 parts-per-quadrillion […]
An early explanation of the periodic table
December 19, 2011
Lars Vegard and X-ray spectroscopy Helge Kragh The Norwegian physicist Lars Vegard may have been the first to propose electron configurations for all the chemical elements, from hydrogen to uranium, on the basis of quantum atomic theory. This he did in papers of 1918-1919 in which he argued that the principal quantum number corresponded to […]
On the interaction between two point electric charges
November 13, 2011
Alexei M. Frolov The general formula for the interaction potential between two point electric charges is derived. This analytical formula has the correct asymtotic behaviour at large distances between two interacting charges. The derivation of this formula is based on the closed analytical expression for the Uehling potential obtained earlier (A.M. Frolov and D.M. Wardlaw, […]
Watching electrons in molecules
October 14, 2011
A research group led by ETH Zurich has now, for the first time, visualized the motion of electrons during a chemical reaction. The new findings in the experiment are of fundamental importance for photochemistry and could also assist the design of more efficient solar cells. In 1999, Ahmed Zewail was awarded the nobel prize in […]
Attoclock turns electrons into movie stars
September 16, 2011
AN ELECTRON takes just billionths of a billionth of a second to escape its host molecule – mere attoseconds. Now we have the first snapshots of what is the initial step in almost every chemical reaction. “We can watch not only the atoms and the nuclei in a chemical reaction. Now we can even watch […]
A Single Atom as a Mirror of an Optical Cavity
September 3, 2011
By tightly focussing a laser eld onto a single cold ion trapped in front of a far-distant dielectric mirror, we could observe a quantum electrodynamic e ect whereby the ion behaves as the optical mirror of a Fabry-Perot cavity. We show that the amplitude of the laser eld is signi cantly altered due to a modi cation of […]
Microscopy, quantum-style: Atomic stacks imaged in real space
September 1, 2011
Since the first optical microscopes appeared in the late 1600s – an exact date and original inventor elude precise identification – microscopy has evolved dramatically. Scanning tunneling microscopy (STM), atomic force microscopy (AFM) and (although not generally recognized as an established method) point contact microscopy (PCM) allow scientists to view objects inaccessible to optical microscopes, […]
British atomic clock ‘most accurate in world’
August 27, 2011
The machine, which is responsible for keeping Britain’s clocks on track and also contributes to the international measure of time, is accurate to within two 10 million billionths of a second. It is one of a handful of similar clocks which determine the exact length of a second by measuring microwaves as they cause reactions […]
Characterize the Behavior of Individual Electrons
August 16, 2011
An international collaboration of researchers is working on a new method of understanding what happens during chemical reactions. The approach is extremely complex, as it involves tracking the behavior of individual electrons as this happens. Doing so is a monumentally difficult task, considering that the elementary particle completes a full orbit around an atomic nucleus […]
100-year-old model of the atom to be celebrated
August 5, 2011
A series of public lectures taking place next week will look at the legacy of Rutherford’s discovery and give citizens of Manchester the chance to join nuclear physicists from around the world in celebrating his 100-year-old model of the atom. The lectures will explain how fundamental physics has moved on from Rutherford’s discovery to the […]
New laser technique makes cold positronium
July 25, 2011
Physicists in the US have shown that positronium – a short-lived bound state of a positron and an electron – can be produced by firing a laser beam onto a silicon surface. Because the technique is highly controllable and operates over a wide range of temperatures, it could prove extremely useful in low-temperature experiments designed […]
Superatoms With Magnetic Shells
June 10, 2011
A team of Virginia Commonwealth University scientists has discovered a new class of ‘superatoms’ — a stable cluster of atoms that can mimic different elements of the periodic table — with unusual magnetic characteristics….. Read more: http://www.sciencedaily.com/releases/2011/06/110608153544.htm
Periodic Table gets new elements (but no one knows what they do)
June 8, 2011
They have existed for less than a second each, but two new elements have been added to the Periodic Table Evidence for the existence of the two elements, the heaviest yet to be included, has been mounting for several years. A number of research teams had claimed to have produced the heavy elements by smashing […]
Antimatter in a bottle: Scientists stabilise the staple of science fiction disasters for 16 whole minutes
June 6, 2011
Scientists have successfully stored anti-matter – the mysterious substance used as a weapon of mass destruction in the novels of Da Vinci Code author Dan Brown. Researchers at CERN, home of the Large Hadron Collider, had bottled antimatter back in 2010, keeping hold of the atoms for a fraction of a second. But CERN have now […]
Graphene may reveal the grain of space-time
May 13, 2011
COULD the structure of space and time be sketched out inside a cousin of plain old pencil lead? The atomic grid of graphene may mimic a lattice underlying reality, two physicists have claimed, an idea that could explain the curious spin of the electron. Graphene is an atom-thick layer of carbon in a hexagonal formation. […]
Interstellar Solid Hydrogen
May 12, 2011
from Ching Yeh Lin, Andrew T.B. Gilbert (Research School of Chemistry, ANU), Mark A. Walker (Manly Astrophysics) “We consider the possibility that solid molecular hydrogen is present in interstellar space. If so cosmic-rays and energetic photons cause ionisation in the solid leading to the formation of H+6. This ion is not produced by gas-phase reactions […]
Confinement of antihydrogen for 1000 seconds
May 3, 2011
..from Antihydrogen Laser Physics Apparatus (ALPHA) Atoms made of a particle and an antiparticle are unstable, usually surviving less than a microsecond. Antihydrogen, made entirely of antiparticles, is believed to be stable, and it is this longevity that holds the promise of precision studies of matter-antimatter symmetry. We have recently demonstrated trapping of antihydrogen atoms by releasing them […]
May 8, 2013
0