All the atoms in the universe just got looser, at least in the eyes of humans. No, the laws of physics didn't change overnight, but our knowledge of how strong atoms are held together did have to be readjusted a bit in light of a new experiment conducted at Harvard University.
By studying how a single electron behaves inside an electronic bottle, Gerald Gabrielse and his colleagues at Harvard were able to calculate a new value for a number six times more precise than the previous measurements called the fine structure constant, which specifies the strength of the electromagnetic force, which holds electrons inside atoms, governs the nature of light and provides all electric and magnetic effects we know, from a flash of lightning to a magnet on a refrigerator. Knowledge of these fundamentals helps scientists and engineers design new kinds of electronic devices–and obtain more profound details on the workings of the universe.
Gabrielse sums up the experiment this way: "Little did we know that the binding energies of all the atoms in the universe were smaller by a millionth of a percent--a lot of energy given the huge number of atoms in the universe."
Electrons are the outermost part of every atom. When detached from their home atoms, electrons constitute the electricity that flows through all powered machines.
By studying an individual electron in isolation from any other particle, scientists can eliminate complications of measuring a single object too small to see with even the most powerful microscopes. The Harvard scientists achieved extraordinary conditions of isolation for their individual electron. First of all, the inside of their trap apparatus is pumped free of almost all other particles, establishing a vacuum comparable to that in interplanetary space. And it's ultra-frigid inside: the apparatus is chilled to millionths of a degree above absolute zero, a temperature far colder than the surface of Pluto.
The lone electron and its surrounding cage constitute a sort of gigantic atom. Combined electric and magnetic forces in the trap keep the electron in its circular orbit. In addition to this circular motion, the electron wobbles up and down in the vertical direction, the direction of the magnetic field. It's like a giant merry-go-round, with an electromagnetic trap as the carousel and the electron as the lone horse.
The circuitry used to activate the electrodes keeping the electron pretty much centered in the trap is so sensitive that the system knows when the electron is bobbing upwards and approaching one of the electrodes. A feedback effect using the combined electric and magnetic forces, supplied by electrodes and coils, restricts the motion of the electron. This allows the electron's energy to be measured with great precision.
By measuring the electron's properties so meticulously, physicists could improve their calculation of the fine structure constant, the number that determines the strength of the electromagnetic forces that hold all atoms together. The new value for the constant is slightly smaller than the best previous value (revealing atoms to be just a tiny bit looser) and six times more accurate.
The Harvard work with the special electron trap has taken more than twenty years and has produced more than a half dozen PhD theses, all centering on a single electron.
James Riordon | EurekAlert!
Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie
Seeing the quantum future... literally
16.01.2017 | University of Sydney
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction