Search
| More

November 27, 2010

Check your brain with the ultimate intelligence test !

Tag
0 comments


Cambridge Brain Sciences, New Scientist and Discovery Channel conceived the 12 Pillars of Wisdom test : a series of 12 cognitive tasks that will test your planning, reasoning, working memory and attentional abilities to the limit.

Click here to begin test (~30 min)

Read more...

November 25, 2010

Antihydrogen: Trapped at CERN

0 comments

The concept of antimatter is not really new, it was predicted for the very first time in 1931 by Dirac. One year later, Carl D. Anderson discovered the positron. The antiproton was experimentally confirmed in 1955 by physicists Emilio Segrè and Owen Chamberlain, and the antineutron was discovered in proton–proton collisions at Bevatron by Bruce Cork in 1956. We must wait almost 40 years for produce 9 antihydrogen atoms at CERN through the LEAR (Low Energy Antiproton Ring), where antiprotons (produced in a particle accelerator), were shot at xenon clusters. Unfortunately this experiment produce highly energetic/warm antihydrogen atoms, which were unsuitable for detailed study. In addition the probability for producing antihydrogen from one antiproton was only about 10−19, so the method was forgetted as an alternative to produce large amount of antihydrogen atoms.
Following the primary goal of produce "cold" (a few thousand kelvin) antihydrogen atoms, in 2002 and 2004, experiments were successfully carried out by the ATRAP and ATHENA collaborations at CERN. The last need, trapping magnetically and for a non negligible time the anti-atoms, was achieved by the ALPHA collaboration (also at CERN). In November 17th, the ALPHA team announced that they had magnetically trapped 38 antihydrogen atoms for at least 172 ms.

Untrapped antihydrogen atoms annihilating on the inner surface of the ALPHA trap. These are measured by the ALPHA annihilation detector. The events are concentrated at the electrode radius of about 22.3 mm. The coordinates are defined in the Nature article, Figure 1b

Even if ALPHA experiment is considered only as a proof of principle, it's clear that it will lead to more robust trapping techniques and set the bases for a new era of fundamental physics tests. Two major subjects should be studied : the gravitational behaviour of antimatter (indications are that gravity should act on antihydrogen just as it acts on hydrogen) and the matter-antimatter symmetry (according to fundamental physics theories, antihydrogen should have the same spectrum as ordinary hydrogen). Subjecting these kind of anti-atoms to rigorous spectroscopic examination would constitute a compelling, model-independent test of the charge conjugation/parity/time reversal (CPT) theorem. In order to be able for doing these studies, the goal of 100 anti-atoms trapped on a timescale of seconds shall be reached.
What's about antimatter real-world applications ? Even if the techniques for trapping magnetically the antihydrogen atoms seems to be identified, we are far far away of concrete applications. Actually, the efficiency of these methods is very weak (only 38 anti-atoms were cold enough and slow enough to be confined from the interaction of about 107 antiprotons and 7 x 108 positrons) and the incarceration time is very short. As said Cliff Surko, a physicist at the University of California, the harnessing of antimatter as an energy source remains a far-fetched idea. "The problem is that ... it takes so much more energy to make than you get out that it's pretty inefficient," he said. "And you have to go to great lengths to confine it for a long time." "Even if the efficiency of the trapping process is increased, it is fundamentally limited by the amount of antiprotons that can be generated. Therefore I do not see applications in terms of new energy sources or weapons." So Star Trek-style propulsion system shall be wait.

Animation of how antihydrogen is trapped (voice of Prof. Joels Fajans from UC Berkeley):

© ALPHA @ CERN

Trapped antihydrogen, by G. B. Andresen, M. D. Ashkezari, M. Baquero-Ruiz, and others. Nature Advanced Online Publication, November 17 (2010) (doi:10.1038/nature09610)
Trapped Antihydrogen

Read more...

November 21, 2010

4049 Nesquik Promotional Set

Tag
0 comments

This set is a Nesquik promotional set from 2001 that contains:
  • the three minifigs, Quicky the Bunny, Director and Cameraman (sets 4051, 4052 and 4053, respectively),
  • and a mini car for the Cameraman.
It's very hard to find this set or the Quicky the Bunny minifig in used state. The price for a new sealed set is 40 euros aproximately and the price for a new Quicky the Bunny minifig (in set 4051) is between 20 euros and 40 euros. That's a lot of money for a little brown rabbit considering that the very rares minifigs of Greedo and Watto cost that much. 

Read more...

November 20, 2010

OMD Cover "VCR" from The xx

Tag
0 comments


OMD’s cover of The xx’s "VCR" (Rough Mix version).

Download now or listen on posterous
OMD-VCR-Rough-Mix.mp3 (8226 KB)

Read more...

November 18, 2010

Viper MK-2 (Galactica)

Tag
0 comments


My last construction made essentially with used bricks. Design by Brickstruct.

Read more...

November 14, 2010

Quantum Quest: A Cassini Space Odyssey

0 comments


Quantum Quest: A Cassini Space Odyssey est un film d'animation de science fiction qui raconte la histoire de Dave, un photon qui refuse de grandir et qui veut quitter son environnement natale : le soleil. Autre le fait de raconter d'une manière toute à fait originale une aventure spatiale depuis un point de vue subatomique, ce film met en valeur les images récupérées lors de 7 missions spatiales de la NASA et de l'ESA : Cassini-Huygens, SOHO, Mars Odyssey, Mars Express, Venus Express et Mercury Messenger. Ce film a aussi la particularité d'être le premier dans son genre à avoir été lancé par la NASA (plus précisément le Jet Propulsion Laboratory) avec un réalisateur de film indépendant dans le but de créer un film d'animation de science fiction basé sur des missions, la science et la découverte. Si vous voyez ce film en VO vous ne serez pas déçu par la panoplie d'acteurs de renommé ayant participé à ce projet : Chris Pine (le capitaine Kirk dans le tout nouveau Star Trek) comme Dave, Samuel L. Jackson comme la Peur, Hayden Christensen (Anakin Skywalker dans les épisodes II et III de Star Wars) comme Jammer, James Earl Jones comme l'Amiral, William Shatner (le capitaine Kirk dans les anciens films de Star Trek) comme le Noyau, Brent Spiner (l'androïde Data dans la série Star Trek : The Next Generation) comme le Coach MacKey, Mark Hamill (Luke Skywalker dans la trilogie Star Wars) comme le Vide, ... Il y a même Neil Armstrong qui prête sa voix dans le rôle du Dr. Jack Morrow.

 

More @ QQtheMovie 

Read more...

A possible new sterile neutrino violates the "charge-parity symmetry" of the universe

0 comments

Recent results on the high-profile Fermilab physics experiment Mini Booster Neutrino Experiment, MiniBooNE, suggest the existence of a new elementary like-neutrino particle: a fourth flavor of neutrino. Scientists previously believed three flavors of neutrino exist, but researchers detected in MiniBooNE more oscillations than would be possible if there were only three flavors.This mean "that there are either new particles or forces we had not previously imagined," said Byron Roe, professor emeritus in the Department of Physics, and an author of the paper "Event Excess in the MiniBooNE Search for ν̅ μ→ν̅ e Oscillations". However this fourth flavor would not interact through the weak force, making it harder to find.

This possible new sterile neutrino is on the mouth of physicists and astronomers because it could possible help to understand the matter-antimatter asymmetry of the universe and why the universe is primarily composed of matter, rather than antimatter. Another non less important conclusion is that results seems to violate the "charge-parity symmetry" of the universe, and then the laws of physics could not be applied in the same ways to particles and their counterpart antiparticles.

Even if the results are statistically significant and confirm previously findings (see LSND experiment), the researchers caution that results over longer periods of time are necessary before any change of the actual standard model.



Full paper available hereafter :
Event Excess in the MiniBooNE Search for Vmu to Ve Oscillations

Read more...

Space news

News from SCIAM

SciFi News

  © Blogger templates Newspaper III by Ourblogtemplates.com 2008

Back to TOP