|
|
|
|
Physics
|
Calling its claims “overly speculative and not credible,” and saying that it is too late anyway, lawyers for the federal government argued this week that a so-called “doomsday suit” intended to prevent the startup of a the world’s most powerful particle accelerator should be thrown out of court.
When it begins operations, the collider will smash together subatomic particles at a rate just short of the speed of light in search of new forms of matter and new laws of physics.
|
|
Conventional wisdom says that the Big Bang was the start of everything, including time, so questions about the Big Bang itself, or what came before, don't make sense. Or so we're told. But the breakdown in the laws of physics — the singularity problem — limits what we know about the starting conditions of the Universe. In the loop quantum universe everything is quantized, or discrete, including time. Freed from the singularity, Bojowald can now look back to a time 'before' the Big Bang. He finds an inverted universe on the other side — a mirror-image of ours — expanding outwards as time runs backwards.
|
|
A lawsuit has been filed in Hawaii in an attempt to hold up the start of operations by the Large Hadron Collider (LHC) atom-smasher on the French-Swiss border.
A colourful American botanist, teacher, former biologist and sometime physicist says (in outline) that the LHC may rip a hole in the fabric of the space-time continuum and so destroy the Earth. He wants the US government to act now and delay the LHC's startup while a new safety review is carried out.
|
|
For the first time ever, researchers have developed a material with a negative refractive index for visible light. Physicists designed a silver-based, mesh-like material.
The discovery marks a significant step forward from existing metamaterials that operate in the microwave or far infrared – but still invisible –regions of the spectrum. Those materials, announced this past summer, were heralded as the first step in creating an invisibility cloak.
Metamaterials make it possible to refract light at a negative angle. This backward-bending characteristic provides scientists the ability to control light similar to the way they use semiconductors to control electricity, which opens a wide range of potential applications.
|
|
I tried to think of a witty, ironic title for this post, but in the end, I simply couldn’t. The above title is a literal statement of fact.
|
 Everyone knows the score with black holes: even if light strays too close, the immense gravity will drag it inside, never to be seen again. They are thought to be created when large stars finally spend all their fuel and collapse. It might come as a surprise, therefore, to find that physicists in the UK have now managed to create an "artificial" black hole in the lab.
The group begins by sending a pulse of light through an optical fibre that, as a result of a phenomenon known as the Kerr effect, alters the local refractive index. A split-second later they send a “probe” beam of light, which has a wavelength long enough to travel faster through the fibre and catch up the pulse. But due to the altered refractive index around the pulse, the probe light is always slowed enough to prevent it from overtaking — so the pulse appears as a white hole. Likewise, if the group were to send the probe light from the opposite end of the fibre, it would reach the pulse but would not be able to go through to the other side — so the pulse would appear as a black hole.
|
 Scientists are a step closer to understanding sunshine. A monumental experiment buried deep beneath the mountains of Italy has provided physicists with a clearer understanding of the sun's heart -- and of a mysterious class of subatomic particles born there.
The researchers have made the first real-time observation of low-energy solar neutrinos, which are fundamental particles created by nuclear reactions that stream in vast numbers from the sun's core.
In stars the size of the sun, most solar energy is produced by a complex chain of nuclear reactions that converts hydrogen into helium. Beginning with protons from hydrogen's nucleus, the chain takes one of several routes that all end with the creation of a helium nucleus and the production of sunlight.
Steps along two of these routes require the presence of the element beryllium, and physicists have theorized that these steps are responsible for creating about 10 percent of the sun's neutrinos. But technological limitations had made the theory difficult to test until now.
|
|
The Collider Detector at Fermilab (CDF) measured a matter-antimatter transition in a fundamental particle called a "B sub s" (Bs) meson. They found that Bs mesons turn into their anti-particles three trillion times every second.
"The interesting aspect of this strange dance between matter and anti-matter is that it completely follows the music of the Standard Model of particle physics. Theories like Supersymmetry, which extend the Standard Model, would expect a much more rapid rhythm for the oscillations between Bs mesons than what our measurements revealed. The new CDF results show that the Standard Model is holding strong. This result constrains Supersymmetry in extending the Standard Model beyond its current foundation."
|
|
|
|
