Measurement is at the heart of physics. As physical quantities have been measured with greater and greater accuracy, our knowledge of the world has improved. This applies equally to measurements on the subatomic and intergalactic scales, although the relative error bars are very different. The Planck constant is known to an accuracy of one part […]
When Victor Hess discovered cosmic radiation almost 90 years ago, he did so in manned balloon flights that reached altitudes of up to 5 km in the Earth’s atmosphere. This was only a few years after the Wright brothers’ first flight and neither they nor Hess are likely to have thought that, by the year […]
Read article: Cosmic rays: an in-flight hazard?
Most materials only become superconducting when they are cooled to low temperatures. In this state the electrons inside the material overcome their natural repulsion and travel through the material in pairs. It has long been suspected that if the surface of a material was doped with enough electrons, the electrons would be pulled into the […]
The New York conference is intended to specify a timetable for all the main nuclear powers – China, France, Russia, the UK and the US – to abandon their nuclear weapon stockpiles. Delegates will also discuss ways to curb the production of weapons-grade fissile material and promote nuclear non-proliferation among the other states. But many […]
Quantized electrical conductance was confirmed in experiments with very narrow conducting wires in the late 1980s. The electrons move through the wire along quantum channels, each of which contributes a quantum unit of 2e2/h to the conductance, where e is the charge on the electron and h is the Planck constant. As the voltage difference […]
All the matter and radiation in the universe was created by the big bang. The radiation stopped interacting with the matter about 300,000 years later – when the universe had cooled down enough for electrons and protons to form hydrogen atoms. The fact that the CMB has a perfect black-body spectrum with a temperature of […]
Read article: The universe is flat – official
Moffatt became interested in the problem while looking for Christmas presents for his grandchildren. “I came across the toy in a mail order catalogue and thought it sounded interesting,” he says. After playing with the toy he became intrigued with the physics behind Euler’s disk. “The disk is continually losing energy throughout the process,” he […]
Read article: The physics of a spinning coin
“This renewal of funding will permit TRIUMF to become a world leader in particle physics research,” said Arthur Carty, President of National Research Council. “It will also retain and attract the leading scientific talent that is essential to build an innovative, knowledge-based economy.” “The federal government is strongly committed to science and technology and has […]
Fundamental physics is a new activity for ESA, although it has ambitious plans to launch LISA, a set of three spacecraft that would detect gravitational waves. It is also considering proposals to test the equivalence of inertial mass and gravitational mass. The other main areas of overlap discussed at the meeting were cosmology, neutrinos, dark […]
Recently a “second decade” working group looked at the future of the billion-dollar telescope, which is funded by NASA and the European Space Agency. After ten years in orbit, what more can Hubble do? “A lot of little science has been explored with relatively short observation periods,” says Ethan Schreier, assistant director at the STScI, […]
Read article: Hubble prepares for the next ten years
