Over the holiday period the arXivblog is re-running the most popular posts from 2008
23 May 2008: First test of exotic space thruster ends in explosion
In 2006, Mason Peck at Cornell University in Ithaca dreamt up with an entirely new way to control satellites orbiting planets that have a magnetic field. The idea is based on the Lorentz force: that a charged particle moving through a magnetic field experiences a force perpendicular to both its velocity and the field.
Over the holiday period, the arXivblog is running a selection of the most popular posts from 2008
29 September 2008 : Forget black holes, could the LHC trigger a “Bose supernova”?
The fellas at CERN have gone to great lengths to reassure us all that they won’t destroy the planet (who says physicists are cold hearted?).
Over the holiday period, the arXivblog is running a selection of the most popular posts from 2008
5 November 2008: Cloaking objects at a distance
One of the disadvantages of invisibility cloaks is that anything placed inside one is automatically blinded, since no light can get in.
Now Yun Lai and colleagues from The Hong Kong University of Science and Technology have come up with a way round this using the remarkable idea of cloaking at a distance. This involves using a “complementary material” to hide an object outside it.
Over the holiday period, the arXivblog is running a selection of the most popular posts from 2008
5 August 2008: Quantum communication: when 0 + 0 is not equal to 0
One of the lesser known cornerstones of modern physics is Claude Shannon’s mathematical theory of communication which he published in 1948 while juggling and unicycling his way around Bell Labs.
Shannon’s theory concerns how a message created at one point in space can be reproduced at another point in space. He calls the conduit for such a process a channel and the limits imposed by the universe on this process the channel capacity.
Over the holiday period, the arXivblog is running a selection of the most popular posts from 2008
29 August 2008: Do nuclear decay rates depend on our distance from the sun?
Here’s an interesting conundrum involving nuclear decay rates.
We think that the decay rates of elements are constant regardless of the ambient conditions (except in a few special cases where beta decay can be influenced by powerful electric fields).
So that makes it hard to explain the curious periodic variations in the decay rates of silicon-32 and radium-226 observed by groups at the Brookhaven National Labs in the US and at the Physikalisch-Technische Bundesandstalt in Germany in the 1980s.
Over the holiday period, the arXivblog is running a selection of the most popular posts from 2008
1 February 2008: Feline ballistics
Here’s a straightforward question in ballistics:
What velocity do you need to launch a 350 pound object over a 12.5 foot barrier that is 33 feet away?
Over the holiday period, the arXivblog is running a selection of the most popular posts from 2008
28 April 2008: First superheavy element found in nature
The hunt for superheavy elements has focused banging various heavy nuclei together and hoping they’ll stick. In this way, physicists have extended the periodic table by manufacturing elements 111, 112, 114, 116 and 118, albeit for vanishingly small instants. Although none of these elements is particularly long lived, they don’t have progressively shorter lives and this is taken as evidence that islands of nuclear stability exist out there and that someday we’ll find stable superheavy elements.
Over the holiday period, the arXivblog is running a selection of the most popular posts from 2008
26 March 2008: Rubik’s cube proof cut to 25 moves
Last year, a couple of fellas at Northeastern University with a bit of spare time on their hands proved that any configuration of a Rubik’s cube could be solved in a maximum of 26 moves.
Now Tomas Rokicki, a Stanford-trained mathematician, has gone one better. He’s shown that there are no configurations that can be solved in 26 moves, thereby lowering the limit to 25.
The iced buns from the physics arxiv blog this week:
The baubles from the physics arXivblog this week:
