Physics

How do scientists store nothing? It may sound like the beginning of a bad joke, but the answer is causing a stir in the realm of quantum physics after two research teams, including one from the University of Calgary, have independently proven it’s possible to store a special kind of vacuum in a puff of gas and then retrieve it a split second later.

In our everyday life, light is completely gone when we turn it off. In the world of quantum physics, which governs microscopic particles, even the light that is turned off exhibits some noise. This noise brings about uncertainty that can cause trouble when trying to make extremely precise measurements.

Today the ATLAS collaboration at CERN celebrates the lowering of its last large detector element. The ATLAS detector is the world’s largest general-purpose particle detector, measuring 46 metres long, 25 metres high and 25 metres wide; it weighs 7000 tonnes and consists of 100 million sensors that measure particles produced in proton-proton collisions in CERN’s Large Hadron Collider(LHC).

The first piece of ATLAS was installed in 2003 and since then many detector elements have journeyed down the 100 metre shaft into the ATLAS underground cavern. This last piece completes this gigantic puzzle.

“This is an exciting day for us,” said Marzio Nessi, ATLAS technical coordinator.

Naval warships are all-powerful vessels but they are also easy to spot.

Concerns about being detected have led the military to develop new stealth technologies that allow ships to be virtually invisible to the human eye, to dodge roaming radars, put heat-seeking missiles off the scent, disguise their own sound vibrations and even reduce the way they distort the Earth’s magnetic field, as senior lecture in remote sensing and sensors technology at Britannia Royal Navy College, Chris Lavers, explains in March’s Physics World.

Wars throughout the twentieth century prompted advances in stealth technologies. Some of the earliest but most significant strides towards invisibility involved covering ships with flamboyant cubist patterns – a technique known as “dazzle painting”.

Many of the greatest inventions in modern medicine were developed by physicists who imported technologies such as X rays, nuclear magnetic resonance, ultrasound, particle accelerators and radioisotope tagging and detection techniques into the medical domain.

There they became magnetic resonance imaging (MRI), computerized tomography (CT) scanning, nuclear medicine, positron emission tomography (PET) scanning, and various radiotherapy treatment methods. These contributions have revolutionized medical techniques for imaging the human body and treating disease.

In 2008, the American Association of Physicists in Medicine (AAPM), is celebrating its 50th anniversary and is calling attention to the field of medical physics achievements.

The best way to do that? Make a top 5 list and publish it here.

Utilizing a technique that combines low temperature measurements and theoretical calculations, Hebrew University of Jerusalem scientists and others have revealed for the first time the electronic structure of single DNA molecules.

The knowledge of the electronic properties of DNA is an important issue in many scientific areas from biochemistry to nanotechnology -- for example in the study of DNA damage by ultraviolet radiation that may cause the generation of free radicals and genetic mutations. In those cases, DNA repair occurs spontaneously via an electronic charge transfer along the DNA helix that restores the damaged molecular bonds.

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.