Physics

Scientists of the Physikalisch-Technische Bundesanstalt (PTB) achieved to transfer very small charge "packets", comprising a well-defined number of few electrons, between metallic electrons precisely by using a single-electron pump.

A single-electron transistor, being able to resolve charge variations of a single electron or less, served as a charge detector to monitor the charge movement. The successful experiment is an important milestone on the way to the setup of a new standard for capacitance, where a capacitor is charged by a well-known number of electrons.

Digital logic, or bits, is the only paradigm for the IT world, and up to now researchers used it almost exclusively to study quantum information processing. But European scientists say that an analog approach is far easier in the quantum world.

Modern computing is digital, a series of 1s and 0s that, once combined, create powerful information processing systems. The system is so simple – on or off, yes or no – that it almost seems dumb. It is that very simplicity that gives digital computing its power. It works very well - but there is a problem. Silicon circuits are getting so small that they will soon be bumping up against a fundamental physical limit.

The raging eruption of dust and water from the south pole of Enceladus, Saturn's sixth-largest moon, has intrigued scientists ever since the Cassini spacecraft provided dramatic images of the phenomenon.

Physicist Nikolai Brilliantov from the University of Leicester and colleagues in Germany, have revealed why the dust particles in the plume emerge more slowly than the water vapour escaping from the moon's icy crust.

Enceladus orbits in Saturn's outermost "E" ring. It is one of only three outer solar system bodies that produce active eruptions of dust and water vapour.

Anyone trying to build sandcastles on the beach will need some degree of skill and imagination, but not an instruction manual. The water content is actually relatively unimportant to the mechanical properties of the sand.

This observation, which is borne out by precise measurements in the laboratory, puzzles researchers.

Even with water content of just 3%, the fluid inside represents a highly-complex structure. The mechanical stiffness of the wet sand remains practically constant with moisture ranging from less than 1% to well over 10%, although the fluid structure changes enormously internally.

I have just completed the first in a series of youtube video's on quantum theory. This one deal with quantum states. In these video's I attempt to explain quantum mechanics in a way that anyone who has graduated high school could understand. The maths will never be more complicated than geometry and algebra and the language will be kept simple. However even with that I think that a basic apprectiation for quantum theory (not just certain sexy phenomena) can be attained. If anyof you see any glaring errors please feel free to chime in a correct me here on on you tube.

Black holes are massive gravitational fields in the universe that result from the collapse of giant stars. Because black holes absorb light, they cannot be studied using telescopes or other instruments that rely on light waves. However, scientists believe they can learn more about black holes by listening for their gravitational waves.

Scientists hope that a new supercomputer being built by Syracuse University's Department of Physics may help them identify the sound of a celestial black hole. The supercomputer, dubbed SUGAR (SU Gravitational and Relativity Cluster), will soon receive massive amounts of data from the California Institute of Technology (Caltech) that was collected over a two-year period at the Laser Interferometer Gravitational-Wave Observatory (LIGO).

Gravitational waves are produced by violent events in the distant universe, such as the collision of black holes or explosions of supernovas. The waves radiate across the universe at the speed of light. While Albert Einstein predicted the existence of these waves in 1916 in his general theory of relativity, it has taken decades to develop the technology to detect them.

When something is moving close to the speed of light, the fastest anything can move, sending ahead information in time to make mid-path flight corrections sounds impossible.

Not quite, say physicists at the Relativistic Heavy Ion Collider (RHIC), a particle accelerator at Brookhaven National Laboratory.

They have developed a way to measure subtle fluctuations in RHIC's particle beams as they speed around their 2.4-mile-circumference high-tech racetrack - and send that information ahead to specialized devices that smooth the fluctuations when the beam arrives.

Squeeze a crystal of manganese oxide hard enough, and it changes from an electrical insulator to a conductive metal. In a Nature Materials report, researchers use computational modeling to show why this happens.

The results represent an advance in computer modeling of these materials and could shed light on the behavior of similar minerals deep in the Earth, said Warren Pickett, professor of physics at UC Davis and an author on the study.

Manganese oxide is magnetic but does not conduct electricity under normal conditions because of strong interactions between the electrons surrounding atoms in the crystal, Pickett said. But under pressures of about a million atmospheres (one megabar), manganese oxide transitions to a metallic state.

Optical clocks might become the atomic clocks of the future. Their "pendulum", i.e. the regular oscillation process which each clock needs, is an oscillation in the range of the visible light.

As its frequency is higher than that of the microwave oscillations of the cesium atomic clocks, physicists expect another increase in the accuracy, stability and reliability. In the case of one of the candidates for an optical clock which is developed at Physikalisch-Technische Bundesanstalt (PTB), strontium atoms are retained in the interference pattern of two laser beams.

Ten years ago, astronomers made the stunning discovery that the universe is expanding at a faster pace today than it did in the past.

“Explaining why the expansion of the Universe is currently accelerating is certainly the most fascinating question in modern cosmology,” says Luigi Guzzo, lead author of a paper in this week’s issue of Nature, in which the new results are presented. “We have been able to show that large surveys that measure the positions and velocities of distant galaxies provide us with a new powerful way to solve this mystery.”

“This implies that one of two very different possibilities must hold true,” explains Enzo Branchini, member of the team.