Clipmarks | Silkweaver's 'physics' clips

Discovery Of 'Broken Symmetry' At Subatomic Level Earns 2008 Nobel Prize In Physics

Tue, 07 Oct 2008 17:36:03 GMT

clipped by: Silkweaver
clipper's remarks: It has proved to be extremely useful, and Nambu’s theories permeate the Standard Model of elementary particle physics. The Model unifies the smallest building blocks of all matter and three of nature’s four forces in one single theory.

The spontaneous broken symmetries that Nambu studied, differ from the broken symmetries described by Makoto Kobayashi and Toshihide Maskawa. These spontaneous occurrences seem to have existed in nature since the very beginning of the universe and came as a complete surprise when they first appeared in particle experiments in 1964.

It is only in recent years that scientists have come to fully confirm the explanations that Kobayashi and Maskawa made in 1972. It is for this work that they are now awarded the Nobel Prize in Physics. They explained broken symmetry within the framework of the Standard Model, but required that the Model be extended to three families of quarks. These predicted, hypothetical new quarks have recently appeared in physics expe

Clip Source: www.sciencedaily.com

The Royal Swedish Academy of Sciences has awarded the Nobel Prize in Physics for 2008 with one half to Yoichiro Nambu, of the Enrico Fermi Institute at the University of Chicago, "for the discovery of the mechanism of spontaneous broken symmetry in subatomic physics,"

and the other half jointly to Makoto Kobayashi, of Japan's High Energy Accelerator Research Organization (KEK) and Toshihide Maskawa, of the Yukawa Institute for Theoretical Physics (YITP) at Kyoto University, "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature."

The fact that our world does not behave perfectly symmetrically is due to deviations from symmetry at the microscopic level.

As early as 1960, Yoichiro Nambu formulated his mathematical description of spontaneous broken symmetry in elementary particle physics. Spontaneous broken symmetry conceals nature’s order under an apparently jumbled surface.

Tags: physics, particle physics, nobel prize, quarks

Invisibility cloaks could take sting out of tsunamis

Sat, 04 Oct 2008 22:34:35 GMT

clipped by: Silkweaver
clipper's remarks: "I think that this is a great idea with much potential," says Ulf Leonhardt at the University of St Andrews, UK. "One could really imagine protecting coastlines by arrays of cleverly designed concrete poles."

Such structures act like metamaterials, materials whose properties result from their structure not composition, and can be used to make invisibility cloaks for light, he says.

But Guenneau cautions that large structures like islands and coastlines are unlikely to become invisible anytime soon, because building the many small islands needed to protect one is such a big job.

"It's crazy – maybe only people in Dubai could do this," he adds, referring to the spectacular artificial islands built there.

Smaller structures such as offshore oil platforms would be easier to protect, he says.

Clip Source: technology.newscientist.com

Invisibility cloaks that are able to steer light around two dimensional objects have become reality in the last few years. But the first real-world application of the theories that made them possible could be in hiding vulnerable coastlines and offshore platforms from destructive tsunamis.

The first working invisibility cloak, built in 2006, guided microwaves around a small, flat copper ring as if it wasn't there.

By October 2007, a device repeated the trick for harder-to-handle visible light, and some progress is reported on the yet more complex task of making cloaks to hide 3D objects

Now Stefan Enoch at the Fresnel Institute in Marseille, France, says that established cloaking principles could be applied to ocean waves, which are essentially two-dimensional.

Such techniques could be used to render vulnerable coastlines or offshore platforms invisible to damaging waves, he says.

Tags: tsunami, wave physics, invisibility

Forget black holes, could the LHC trigger a “Bose supernova”?

Sat, 04 Oct 2008 22:29:00 GMT

clipped by: Silkweaver
clipper's remarks: Nobody is exactly sure how these explosions proceed which is a tad worrying for the following reason: some clever clogs has pointed out that superfluid helium is a BEC and that the LHC is swimming in 700,000 litres of the stuff. Not only that but the entire thing is bathed in some of the most powerful magnetic fields on the planet.

If not for anything else, the LHC has become a modern doom spelling myth. The universe is about to punish us for prying on its privacy...
These modern myths are truly fascinating.

After Bose Nova? Bose Supernova!

Clip Source: arxivblog.com

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?).

The worry was that the collision of particles at the LHC’s high energies could create a black hole that would swallow the planet. We appear to be safe on that score but it turns out there’s another way in which some people think the LHC could cause a major explosion.

The worry this time is about Bose Einstein Condensates, lumps of matter so cold that their constituents occupy the lowest possible quantum state.

Physicists have been fiddling with BECs since the early 1990s and have become quite good at manipulating them with magnetic fields.

But get this: in 2001, Elizabeth Donley and buddies at JILA in Boulder, Colorado, caused a BEC to explode by switching the forces like. These explosions have since become known as Bose supernovas.

Tags: lhc, physics, bose condensates

Counterintuitive physics may help everyone drive home quicker

Thu, 02 Oct 2008 18:25:35 GMT

clipped by: Silkweaver
clipper's remarks: The second concept, the Nash equilibrium, occurs when an individual cannot choose a better strategy for himself if other individuals keep their strategies unchanged (i.e. an individual can not improve his situation by changing unilaterally). In the traffic situation, say you know which routes the other drivers take, maybe because you’ve tried different routes to find out which is the fastest way to get home from work. After trying different routes, you choose the route that is fastest for yourself. Then you cannot find a faster route as long as the other drivers stick to their same routes (which they do, because they cannot find faster routes, either).

But if many drivers could change their routes simultaneously, then the effect might be a decrease in everyone’s travel time, and society would come closer to the social optimum rather than languishing in the Nash equilibrium. The scientists found that modifying the network structure can sometimes lead to faster overall travel times,

Clip Source: www.physorg.com

If you're trying to drive to a destination as quickly as possible, you might think that knowing the traffic conditions would help you choose the quickest route for yourself. Traffic reports and new GPS technologies that provide traffic data are based on this assumption – but scientists have found that knowing this information may do more harm than good.

A recent study has investigated just how much time is lost due to individuals opting for strategies that maximize their own personal utility rather than the social optimum, which often aren’t the same.

call this lost time “the price of anarchy” (POA) that society must pay for the lack of individual coordination.

At the core of the price of anarchy are two related concepts: Waldrop’s principle and the Nash equilibrium. Waldrop’s principle, which is fairly obvious, says that humans approach the problem of finding routes in a network from the self-interested perspective of finding the quickest route for themselves.

Tags: game theory, systems theory, traffic

Fermilab Looks for Visitors from Another Dimension

Fri, 19 Sep 2008 12:23:50 GMT

clipped by: Silkweaver
clipper's remarks: The prospect of extra dimensions is fascinating. ET might already be here in a neighbour dimension.

Estimated to cost about $15 million, the MicroBooNE tank would be located near the MiniBooNE detector at Fermilab so that it could observe the same beam of neutrinos. This past June the lab’s physics advisory committee approved the design phase for the project; if all goes well, the detector could begin operating as soon as 2011.

Clip Source: www.sciam.com

The detection of extra dimensions beyond the familiar four—the three dimensions of space and one of time—would be among the most earth-shattering discoveries in the history of physics.

Now scientists at the Fermi National Accelerator Laboratory in Batavia, Ill., are designing a new experiment that would investigate tantalizing hints that extra dimensions may indeed exist.

Last year researchers involved in Fermilab’s MiniBooNE study, which detects elusive subatomic particles called neutrinos, announced that they had found a surprising anomaly.

The mystery has focused attention on an intriguing and very unconventional hypothesis: a fourth kind of neutrino may be bouncing in and out of extra dimensions.

String theorists, who seek to unify the laws of gravity with those of quantum mechanics, have long predicted the existence of extra dimensions.

Tags: physics, extra dimensions, neutrinos

I'm Sorry Dave. I'm Afraid I Must Collide Proton Beams.

Wed, 10 Sep 2008 23:26:44 GMT

clipped by: Silkweaver
clipper's remarks: An Exciting Journey begins...

Clip Source: cache.boston.com

Clip Source: blog.wired.com

Over the last few decades, physics has followed a path of increasing strangeness. Theory after theory about the fundamental nature of the universe has arisen: string theory, universes composed of multiple universes and many dimensions, and matter we can't see and can hardly detect. Now, that generation of theoreticians will have their ideas put to the test deep underground on the border of France and Switzerland.

Here's how the LHC could bolster or banish five of those theories:

The Big Bang Theory

String Theory

[Video]

The "Our Universe Is Not Alone" Theory

The Dark Matter of the Universe Theory

The Standard Model of Particle Physics

[Video]

Tags: physics, lhc

Celebrate The Launching of the LHC with a Cool Physics Rap

Mon, 08 Sep 2008 01:21:28 GMT

clipped by: Silkweaver
clipper's remarks: The coolest way to update on high energy particle physics.

Clip Source: www.dailymail.co.uk

[Video]

The Large Hadron Collider may be causing fears for the future of the world, but it has become the bizarre setting for an unlikely music hit.

Written and performed by 23-year-old Kate McAlpine, who works in the Press office at the CERN laboratory in Switzerland, the video features Kate and two background dancers bopping about in lab coats.

A long way from rap’s usual subjects of violence and crime, the rap focuses on the science of high-energy particle physics.

One section goes: ‘Two beams of protons/ swing ’round./ Through the ring they ride/’til in the hearts of the detectors/ they’re made to collide!/ And all that energy packed/ in that tiny room/ becomes mass,/ particles created from the vacuum.’

A CERN spokesman said: ‘We love the rap and the science is spot on.’

Tags: physics, rap music, lhc

Physicists investigate how time moves forward

Sat, 06 Sep 2008 00:52:40 GMT

clipped by: Silkweaver
clipper's remarks: This provides an orientation, or arrow of time, and it is generally believed that all other time asymmetries, such as our sense that future and past are different, are a direct consequence of this thermodynamic arrow.”

In their study, Feng and Crooks have developed a method to accurately measure “time asymmetry” (which refers to our intuitive concept of time, that the past differs from the future, in contrast with time symmetry, where there is no distinction between past and future). They began by investigating the increase in energy dissipation, or entropy, in various arrangements.

While time blatantly moves forward in the macroscopic world, the direction of time becomes confusing on the scale of a single molecule

Clip Source: img.timeinc.net

Clip Source: www.physorg.com

As humans, we have a very intuitive concept of time, and of the differences between the past, present, and future. But, as scientists Edward Feng of the University of California, Berkeley, and Gavin Crooks of the Lawrence Berkeley National Laboratory point out, science does not provide a clear definition of time.

In our everyday lives we have the sense that time flows inexorably from the past into the future; water flows downhill; mountains erode; we are born, grow old, and die; we anticipate the future but remember the past,” the scientists write in a recent study in Physical Review Letters. “Yet almost all of the fundamental theories of physics – classical mechanics, electrodynamics, quantum mechanics, general relativity, and so on – are symmetric with respect to time reversal.

The only fundamental theory that picks out a preferred direction of time is the second law of thermodynamics, which asserts that the entropy of the Universe increases as time flows toward the future

Tags: physics, time

Evangelical Scientists Refute Gravity With New 'Intelligent Falling' Theory

Fri, 05 Sep 2008 01:31:17 GMT

clipped by: Silkweaver
clipper's remarks:

Clip Source: www.theonion.com

As the debate over the teaching of evolution in public schools continues, a new controversy over the science curriculum arose Monday in this embattled Midwestern state.

Scientists from the Evangelical Center For Faith-Based Reasoning are now asserting that the long-held "theory of gravity" is flawed, and they have responded to it with a new theory of Intelligent Falling.

"Things fall not because they are acted upon by some gravitational force, but because a higher intelligence, 'God' if you will, is pushing them down," said Gabriel Burdett, who holds degrees in education, applied Scripture, and physics from Oral Roberts University.

Burdett added: "Gravity—which is taught to our children as a law—is founded on great gaps in understanding.

Isaac Newton himself said, 'I suspect that my theories may all depend upon a force for which philosophers have searched all of nature in vain.' Of course, he is alluding to a higher power."

Tags: humor

Identity and Individuality in Quantum Theory

Wed, 27 Aug 2008 23:54:56 GMT

clipped by: Silkweaver
clipper's remarks: Interesting read in the foundation of quantum physics.

Clip Source: mahinth.blogspot.com

Clip Source: plato.stanford.edu

What are the metaphysical implications of quantum physics?

One way of approaching this question is to consider the impact of the theory on our understanding of objects as individuals with well defined identity conditions.

One view is that quantum theory implies that the fundamental particles of physics cannot be regarded as individual objects in this sense.

Such a view has motivated the development of non-standard formal systems which are appropriate for representing such non-individual objects.

However, it has also been argued that quantum physics is in fact compatible with a metaphysics of individual objects.

1. Introduction

2. Quantum Non-Individuality

3. Quantum Individuality

4. Quantum Physics and the Identity of Indiscernibles

5. Non-individuality and self-identity

6. Metaphysical Underdetermination

Bibliography

Other Internet Resources

Tags: quantum physics, metaphysics

Exploding chromosomes fuel research about evolution of genetic storage

Sat, 23 Aug 2008 13:01:12 GMT

clipped by: Silkweaver
clipper's remarks: Dinoflagellates are stuffed at the core with tightly compacted chromosomes, yet these organisms contain neither histones nor nucleosomes. "What takes care of neutralizing DNA, to allow chromosomes to condense?" Levi-Setti asked. "Most biology books do not tell you."

Other scientists had already identified positively charged atoms called cations as neutralizing factors. They found that dinoflagellate chromosomes explode upon the removal of calcium and magnesium cations.

Levi-Setti has produced the first images of the distribution of these cations in dinoflagellate chromosomes. These images verify that cations, mainly of calcium and magnesium, neutralize DNA's enormous negative charge, and further suggest a critical role in folding the protein as well.

The finding raises questions about the evolution of chromosomes, Rizzo said. "Did dinoflagellates once have histones and then lost them? Or did dinoflagellates never have histones and just 'figured out' a different way to fold lar

Clip Source: www.labspaces.net

Human cells somehow squeeze two meters of double-stranded DNA into the space of a typical chromosome, a package 10,000 times smaller than the volume of genetic material it contains.

"It is like compacting your entire wardrobe into a shoebox," said Riccardo Levi-Setti, Professor Emeritus in Physics at the University of Chicago.

Now research into single-celled, aquatic algae called dinoflagellates is showing that these and related organisms may have evolved more than one way to achieve this feat of genetic packing.

Even so, the evolution of chromosomes in dinoflagellates, humans and other mammals seem to share a common biochemical basis

Packing the whole length of DNA into tiny chromosomes is problematic because DNA carries a negative charge that, unless neutralized, prevents any attempt at folding and coiling due to electrostatic repulsion.

In humans and mammals, proteins called histones partially neutralize the DNA's negative charge.

Tags: genetics, chromosomes, evolution

Transformers - The Nature of Alien Life

Sat, 23 Aug 2008 12:52:47 GMT

clipped by: Silkweaver
clipper's remarks: The driving factor is a pragmatic desire to improve mental capacity. Alien beings may have already reached a point in their evolution where, having exhausted the potential of their biological brains, they have taken the next logical step and opted for robotic brains equipped with artificial intelligence. This brain swap may not be as far off for humans as one might think. In only a few decades, the computer revolution here on Earth has produced supercomputers capable of performing more than a quadrillion calculations per second.

According to research by Hans Moravec, an artificial-intelligence expert at Carnegie Mellon University, that rate trumps the human brain’s estimated top speed of 100 trillion calculations per second. Some scientists speculate that in a few decades, an event called the technological singularity will occur, and machines armed with computer brains will become sentient and surpass human intelligence. Civilizations equipped with technology light-years ahead

Clip Source: kemo-d7.livejournal.com

The existence of a race of sentient alien robots might be
not just possible, but inevitable.

Daniel C. Dennett points out that we do not consider chemicals to be alive. Even self-replicating crystals and clever nanobots are not "living"; we consider them to be completely mechanical. Yet we are made of these non-living, "mechanical" chemicals. Not only are we made of robots, and we still consider ourselves to be valid conscious life, but the evolution of all life is from such mindless robots.

As life is based in biology, and biology in biochemistry, chemistry is based on the cold, non-living laws of physics.

Given the current pace of development, it is easy to imagine artificial life venturing out into the universe and leaving us fragile humans behind.

In fact, we might be living in a "post-biological universe" right now, in which intelligent extraterrestrials somewhere have exchanged organic brains for artificial ones.

Tags: ai, science fiction, alien life

Physicists Seek Answers to Quantum Correlations

Mon, 18 Aug 2008 01:44:51 GMT

clipped by: Silkweaver
clipper's remarks: The physicists ruled out several possible classical explanations for the instantaneous communication. For one thing, they showed that the photons did not share information before leaving Geneva, and so they didn´t travel knowing about each other´s properties.

In another test, the scientists showed that no communication could have occurred through a different reference frame, as might happen because of the photons´ high speeds. According to Einstein´s theory of relativity, observers moving at high speeds can get different measurements of the same event because they have different reference frames. But, by performing tests over a complete rotation of the Earth, the researchers ruled out this possibility.

"We think space and time are important because that´s the kind of monkeys we are,"

Clip Source: www.physorg.com

After performing multiple tests on two entangled photons, physicists have yet again found that the photons seem to be communicating faster than the speed of light - at least 100,000 times faster.

The researchers hope that their results might encourage theorists to come up with new explanations for the strange quantum mechanical effect.

The physicists, led by Nicolas Gisin from the University of Geneva, arranged their experiment by sending two photons down fiber optic cables to detectors in two Swiss villages located 18 km apart. Both photons started in Geneva, with one heading toward Satigny and the other toward Jussy.

When the researchers measured several properties of each photon at its destination, they found that the particles could instantly sense the other´s behavior without any known communication.

Although this correlation obeys the laws of quantum mechanics, it seems to defy the nature of space and time, at least from humans´ everyday perspectives.

Tags: physics, quantum physics, entaglement

String Theory Faster-Than-Light Drive Proposed

Wed, 13 Aug 2008 22:18:29 GMT

clipped by: Silkweaver
clipper's remarks: Dreams of interstellar travel may need to be put on hold for the moment, however. Cleaver and Obousy estimate that the amount of energy needed to influence the extra dimension is equivalent to the entire mass of Jupiter being converted into pure energy for a ship measuring roughly 10 meters by 10 meters by 10 meters. "That is an enormous amount of energy," Cleaver said. "We are still a very long ways off before we could create something to harness that type of energy."

But what if we could make ourselves very very small??? I am ready to squeeze myself quite a bit to get really far...

Clip Source: www.scienceagogo.com

Physicists Gerald Cleaver and Richard Obousy, of Baylor University, believe they have come up with a new method for a spaceship to travel faster than the speed of light without breaking the laws of physics.

They theorize that by manipulating the extra spatial dimensions of string theory around a spaceship with an extremely large amount of energy, it would create a "bubble" that could cause the ship to travel faster than the speed of light.

The Baylor physicists believe that manipulating the 10th spatial dimension postulated in string theory would alter the dark energy in three large spatial dimensions: height, width and length.

The new method is based on the Alcubierre drive, which proposes expanding the fabric of space behind a ship and shrinking space-time in front of the ship.

The ship would not actually move, rather the ship would sit in a bubble between the expanding and shrinking space-time dimensions.

Tags: physics, string theory, faster than light drive

Quantum Crystals: A Solution to Inexpensive & Efficient Green Energy?

Wed, 13 Aug 2008 00:34:05 GMT

clipped by: Silkweaver
clipper's remarks: Innovalight is already planning to make flexible solar panels available at a cost that could be as much as ten times cheaper than the current solar cell technology.

Clip Source: www.dailygalaxy.com

Those concerned about Earth’s future will be encouraged to hear about the announcement by scientists at the U.S. Department of Energy. They reported the discovery of a unique quantum physics effect in silicon nanocrystals, which should eventually help humankind come much closer to the goal of leaving “dirty” energy behind.

The researchers

discovered a new effect called Multiple Exciton Generation (MEG).

The effect occurs efficiently in silicon nanocrystals, resulting in the formation of more than one electron per absorbed photon, the scientists reported.

When today’s photovoltaic solar cells absorb a photon of sunlight, about 50 percent of the incident energy is lost as heat. MEG provides a way to convert energy lost as heat into additional electricity.

The finding might lead to the application of MEG for greatly enhancing the conversion efficiency of solar cells based on silicon.

Tags: solar energy, clean energy, quantum physics