Archive for December, 2009

CDMS gives possible evidence for dark matter

Published in Physics World, 18 Dec 2009

For weeks physicists have been speculating whether the CDMS-II collaboration based in the US has detected the first direct evidence for dark matter, one of the universe’s most mysterious entities. Now the evidence is out in the open – although it’s not quite a strong as some had hoped.

In a preprint submitted to the arXiv server yesterday, the CDMS-II team claim to have detected two “events” that are characteristic of dark-matter constituents known as weakly interacting massive particles, or WIMPs. However, they point out that there is a one-in-four chance that these events could be background noise. [...]

The rest of this article is available here.

Tags:
Posted in Dark matter | Comments Off

Star wars

Published in Prospect, 16 Dec 2009

Will the EU’s “civilian” satellites also be used to guide bombs?

By 2013, if all goes to plan, a constellation of European satellites will have launched into the sky to form Galileo, a new instrument for satellite navigation. According to the European commission’s brochure, the €3.4bn (£3.1bn) system is “specifically designed for civil purposes”—including sat nav for cars, oil drilling, aviation and shipping. It will create 100,000 jobs, as well as €200bn of new markets in areas like transport, energy, finance and agriculture.

However, absent from this list is any mention of the military. Since the 1980s, the US global positioning system (GPS)—Galileo’s only fully operational counterpart—has helped co-ordinate the US military’s ground, sea and air operations. Today, GPS guides drones, smart bombs and cruise missiles, and is one of the key assets that makes the US a superpower.

Galileo began life in 1999 to provide satellite navigation independent from the US. Financed chiefly by EU civil budgets, the 30-satellite project was intended to be more accurate than GPS and, crucially, operate even if the US chose to switch off GPS signals at times of conflict.

At the start, Galileo’s military potential was also an open, if cautious, talking point. In 2001, the then President Chirac said the system would help “the development in Europe of a common security and defence identity.” Britain was a co-founder of that identity but, mindful of its special relationship with the US, it was less keen on a military role for Galileo, and by the following year public talk of military use disappeared. [...]

The rest of this article is available here.

Tags:
Posted in Militarization | Comments Off

Higgs could reveal itself in dark matter collisions

Published in Physics World, 10 Dec 2009

For particle physicists analysing the first data from CERN’s Large Hadron Collider (LHC) in Geneva, it is the €4.3 bn question: is there a particle known as the Higgs, which endows all others with mass? But now a study suggests that there might be a far cheaper method of finding the answer – and gargantuan particle accelerators don’t get a look-in.

According to Marco Taoso of CERN and colleagues, the famed Higgs could be leaving its imprint in the light produced in collisions of dark matter, the substance believed by most scientists to make up the vast majority of the universe’s mass. In fact, the researchers think we could be seeing the tell-tale spectral signatures of the Higgs in this way within a year – so sooner, potentially, than the LHC unscrambles data on the elusive particle. [...]

The rest of this article is available here.

Tags:
Posted in Dark matter, Particle physics | Comments Off

Earth’s response to CO2 underestimated

Published in Physics World, 9 Dec 2009

Global warming resulting from slowly changing Earth systems could be up to 50% greater than previously thought, according to research by UK and US scientists. The study reinforces the notion that certain poorly understood systems such as ice sheets or vegetation are integral to accurately predicting future temperatures. It also paints an ever-bleaker outlook for our planet at a critical time when world leaders are gathering for a United Nations conference in Copenhagen to discuss practicable ways of mitigating climate change.

“If we want to build an agreement that is going to last for many, many centuries – so for our grandchildren’s grandchildren’s grandchildren’s grandchildren – then we need to be taking in these issues,” lead author Dan Lunt of the University of Bristol told physicsworld.com. [...]

The rest of this article is available here.

Tags:
Posted in Climate change | Comments Off

Physics takes the wobble out of rowing

Published in Physics World, 3 Dec 2009

Every year, teams of rowers from Oxford and Cambridge universities sweep along the Thames river at close to 15 miles per hour in one of the world’s most famous boat races. In each boat, the oars lie alternately left and right to generate – one might assume – an even push. But is this the most effective rig?

Possibly not, according to John Barrow, a theoretical physicist at Cambridge. While not a rower himself, Barrow has produced a formula that shows which rigs will naturally travel in a straight line, without a finite mechanical moment that causes them to wiggle left and right. For an eight-oared boat there are several possible zero-moment rigs – and the traditional Oxbridge “eight” isn’t one of them. [...]

The rest of this article is available here.

Tags:
Posted in Uncategorized | Comments Off

Reading between the lines

Published in Chemistry World, 1 Dec 2009

We will surely never solve all the mysteries of the universe. But, as Jon Cartwright reports, spectroscopy holds the key to unravelling many planetary secrets

Stars, planets and other gems in the night sky for so long seemed, both literally and metaphorically, worlds apart. Even the great 19th century French philosopher Auguste Comte, for all his novel perspectives on science, wrote that the internal make-up of ‘heavenly bodies’ would be ‘forever excluded from our recognition’. How wrong he was.

Today, there is no question of unravelling the make-up of objects in space. We know that elements found on Earth, namely hydrogen and helium, are also found on our sun. We know that the sun itself is just one of many trillions of stars, of which some are bigger, hotter, and contain heavier elements. We know the basic composition of planets in our solar system and that similar planets exist in systems throughout the galaxy. We even know a little about how these structures came to be, their dynamics, and how they are evolving in space and time. [...]

The rest of this article is available here.

Tags:
Posted in Optics, Planets, Stars | Comments Off