Skip to main content

Posts

Showing posts from April, 2011

Connecting the dark with the light

Just this month, the CDF experiment at Fermilab saw a bump in their data at an energy of 140-150 GeV suggesting that they had seen a new type of particle. But does it really exist and, if so, what is it?

The result was at the 3.2 sigma level, which in statistics means that it is about three standard deviations away from the null hypothesis--or about a 6 in 10,000 chance that the signal is just a statistical fluctuation. That's a small chance but particle physicists have high standards when it comes to this sort of thing.

In particle physics, a 3 sigma result is often described as "evidence" for something but it takes a 5 sigma result to claim "discovery." The trouble is, there are lots of 3 sigma results in particle physics that go away with more data, usually because of some unsuspected systematic error. That doesn't change the likelihood that this result is correct but says that 3 sigma is not actually a discovery, just a promising hint.

[Photo courtesy of…

Hinting at dark matter

We haven't seen dark matter yet. We haven't, right? Sitting in a plenary talk at the APS April meeting today I started to have my doubts.

Dan Hooper from Fermilab gave a great overview discussion of the attempts to detect dark matter covering the three major techniques: direct detection, where you see dark matter particles collide with nuclei; indirect detection, where you use telescopes to observe the gamma rays produced by dark matter annihilating; and collider detection, where you create the dark matter in something like the Tevatron or the Large Hadron Collider.

[Photo courtesy of Echo Romeo]
In the discussion, Hooper pointed out the various experiments which have seen hints of dark matter. Of these, only one is claiming to have definitively seen dark matter--the DAMA collaboration, which looks for seasonal variance in a signal representing the amount of dark matter hitting the Earth. Nobody doubts they have seen a signal, there is just debate about whether it is due to dark …

Quantum Man

If you happen to be near Anaheim, CA on Monday, you'll get a chance to sit in on a free lecture featuring Lawrence Krauss discussing the life and science of Richard Feynman.



Krauss, one of the country’s leading physicists and science authors, provides a unique perspective on the Nobel Laureate, visionary, and self-described curious character that was Professor Feynman. The lecture takes place Monday, May 2, 7:00 p.m. - 9:00 p.m. at the Hyatt Regency Hotel in Anaheim, California.

More than twenty years after his death, Feynman remains one of the most legendary people in science. His collected lectures and books have inspired a generation of scientists and nonscientists alike with profound insights, humor and awe-inspiring predictions that have expanded the boundaries of science and technology.

Lawrence Krauss is director of the Origins Project at Arizona State University and author of seven books including the wildly popular Physics of Star Trek. His latest book, Quantum Man: Richard …

Royal Weddings in Space!

This article made me laugh when I read it last week. I was lamenting the fact that TV viewers might have to choose between watching the royal wedding or the space shuttle launch tomorrow. Then a colleague of mine pointed out that people who watch one might not necessarily watch the other. What a shame, I thought. How can we remedy that? There's only one solution: Royal weddings in space!

[What Prince William & Kate Middleton's nuptials aboard the International Space Station might look like.]

What might be different about a royal wedding in space? First off, the princess-to-be wouldn't have to worry about whether to arrive by car or carriage: She would arrive by space shuttle! (Or Soyuz capsule.)

Instead of walking gracefully down the aisle, Kate and her bridesmaids could float from one module of the International Space Station (ISS) to the other.

If the wedding is 90 minutes long, the ISS will complete one orbit around the Earth and the whole world can be a part of t…

Small insects paddle through air

Just as a kayaker uses a paddle to push his or her kayak through the water, small insects use their wings to push themselves through the air, using the force of drag. Unlike birds who use the force of lift to fly through the air, insects swim through the air, pushing it behind them like a fish pushes aside water.


[High speed video (8000 images a second or 40 frames per wing beat) of free-flying mosquitoes; filmed at Cornell University in 2009.]
Birds and airplanes use lift - the pressure difference between the top and bottom of a wing - to fly through the air. Most animals going through water, though, use the force of drag to propel themselves along: they reach out and push the water behind them.

To small animals, like tiny flying insects, the air that makes up Earth's atmosphere can feel thick and heavy like water feels to humans. They need more of a push than lift alone to move through the thick atmosphere.

Researchers Leif Ristroph, John Guckenheimer, Z. Jane Wang and Itai Cohen, …

More Superconductivity at the March Meeting

[In this Physicsworld.com video, Nobel Laureate Frank Wilczek talks about superconductors, topological insulators, quantum computers and more at the 2011 APS March Meeting.]

Nobel Laureate Frank Wilczek, of the Massachusetts Institute of Technology, talks with Physicsworld.com's Hamish Johnston at the 2011 APS March Meeting about the crossover between various physics disciplines. They also discussed the difficulties in solving problems with high temperature superconductors.

"It's hard to know what's going on in high temperature superconductivity," Wilczek said. "People have ideas that seem entirely disconnected from each other." Wilczek shared the 2004 Nobel Prize for Physics with David J. Gross and H. David Politzer for their discovery with the quantum field theory called quantum chromodynamics.

The centennial of the discovery of superconductivity was celebrated at the March Meeting. For more, check out the original Physicsworld.com article.

Higgs?

"We know everything about the Higgs boson," Rolf-Dieter Heuer said. "We just don't know if it exists." The director-general of CERN (the European Organization for Nuclear Research) spoke confidently to a group at the University of Maryland April 12 about the hunt for the elusive particle that keeps the Large Hadron Collider (LHC) busy. Over the weekend, rumors surfaced that the ATLAS particle detector at the LHC may have detected the Higgs for the first time.

[The ATLAS experiment as it appeared in November 2005.]

Heuer spoke to a crowd in the large physics lecture hall at the University of Maryland. He gave a status update of everything going on at CERN and explained why the Higgs is such a big deal.

"The cornerstone of the standard model is missing," Heuer said. "We don't know how to generate mass."

The standard model of particle physics says there are 17 elementary particles that make up matter. Sixteen have been observed but one, the o…

Happy Earth Day!

Happy Earth Day! Don't we live on a beautiful planet?

[Earth: The Water Planet. Photo credit: NASA]

Of all the (eight, sadly) planets in our solar system, ours is the only one parked at just the right distance from the sun to support life. This distance is called the Goldilock's Zone - where it's not too hot (close to the sun) and it's not too cold (far away from the sun) but instead (you guessed it) just right for supporting life.

The Goldilock's Zone, also known as the less exciting "habitable zone," is the distance from a star where a planet like Earth can keep liquid water on its surface without it freezing or boiling away, enabling it to support carbon-based life like that on Earth. This zone exists both within a planetary system, like our solar system, and also within a galaxy.

The Zone is not the same for every planetary system. A star that shines 25 percent as brightly as the sun will have a habitable zone that's twice as close to the star as we…

Michele Dufault

It's always sad to hear about tragedy within your community, especially when it involves someone young and promising. We at PhysicsBuzz and Physics Central are very saddened by the death of Yale University physics and astronomy undergrad Michele Dufault.

Dufault, a senior at Yale, was working alone on her senior project in a chemistry laboratory late at night on April 12 when her hair apparently became caught in a lathe - a rotating machine that shapes wood or metal. It is believed she was pulled into the machine and died of asphyxia. She was discovered in the lab by other students and emergency workers arrived sometime near 2:30 a.m.

Dufault was very involved in several physics groups and had worked on projects for the Woods Hole Oceanographic Institution, where she worked on underwater robotic vehicles, and NASA,
where she worked on a plasma physics experiment.

The lab where Dufault was working, Sterling Chemistry Laboratory, was closed for a time following the accident and the Occ…

Microclimates: Managing Weather From Street To Street

Considering cities -- not just individual buildings -- improves energy-efficient design.



Walk through a city and the weather may change from block to block, often in startling ways.

Step into a canyon of tall buildings and sunlight disappears. Winds arise seemingly from nowhere. The air smells completely different on a balcony and in the street.

City buildings create their own microclimates. Ignoring these variations can make life uncomfortable for inhabitants and prevent buildings from achieving true energy efficiency, according to Evyatar Erell, a professor of architecture at Israel's Ben-Gurion University of the Negev.

"Even when architects design a green building, it may not make the best use of the environment because other buildings get in the way," he said.

Erell is the lead author of a new book, "Urban Microclimate: Designing the Spaces Between Buildings", that shows how to apply climatology to create greener, more livable cities.

"What we're seeing …

The New School of Superconductors

[Physicsworld.com video about superconductivity from the 2011 APS March Meeting]
In 2008, the discovery of iron-based, high-temperature superconductors excited scientists and a new class of superconductors was created to compete with the old. Laura H Green of the University of Illinois Urbana-Champaign spoke with Physicsworld.com's Joe McEntee at the 2011 APS March Meeting about why so much excitement continues to come out of this discovery.

Physicists celebrated the centennial of the discovery of superconductors at this year's March Meeting held in Dallas.

For more, check out the original physicsworld.com article.

Snake venom: Groovy, baby!

A team of six scientists from the University of Massachusetts Lowell and the Technische Universit√§t M√ľnchen (the Technical University of Munich, Germany) used biophysics to explain how snakes use grooved fangs to deposit venom in victims.

[These images show grooves (white arrows) on the fangs of (A) a banded snake (Bothryum lentiginosum) and (B) a mangrove snake (Boiga dendrophila) . In (B), the fang is embedded in the tissue of the snake's prey with only the base of the fang visible. The prey's tissue has separated from the fang, creating a venom tube (yellow arrow) with three walls defined by the fang and one wall defined by the tissue.]

Some snakes have tubing inside their fangs that distributes globules of venom in prey like a syringe. Most venomous snakes, however, along with many other reptiles, deposit venom in prey via a groove that runs down the middle of each fang.

Bruce Young, from the University of Massachusetts Lowell and his German colleagues, Florian Herz…

Folding paper: How hard can it be?

There's not much to it: Folding paper. So what's the big deal with folding a piece of paper in half umpteen times? It's a very big deal, apparently. Don't believe me? Try it.


[Fifteen students from St. Mark's School in Southborough, Mass., fold 13,000 ft. of toilet paper in half 13 times.]

A group of fifteen high school students from St. Mark's School in Southborough, Mass., claimed to have set a new record when they folded a 13,000 ft. roll of single-ply toilet paper in half 13 times - beating the former 12-fold record. Led by teacher James Tanton, the students worked with the Massachusetts Institute of Technology origami club, OrigaMIT, to help gain access to MIT's Infinite Corridor (an 825-foot-long hallway connecting several campus buildings) where they accomplished their feat.

In the video though, it's hard to tell how well the team actually accomplished the 13th fold. As I watch the video, I can't help thinking, "How hard can it be?" T…

May the Force be Withheld

The Chinese government has placed a ban on television programming portraying time travel (think of shows like "Dr. Who" and "Star Trek"), saying that going back in time to alter events is against the Chinese spirit. Its State Administration of Radio Film and Television has singled out shows portraying time travel, but the language used could extend to other science fiction staples as well. Which makes us wonder, how will China inspire its young scientists?


Here's a horrible Google translation of one paragraph from the original Chinese guidelines published on March 31:
In recent months, the national report prepared by the general trend is good repertoire, but we also found signs of some incorrect creation: individual declaration of the record through the supernatural drama and drama, random compilation of myths, bizarre plots, bizarre, absurd way, and even rendering of feudal superstition, fatalism and reincarnation, value orientation ambiguity, the lack of signif…

Time to Update the Table of the Elements

It seems like something we should do periodically (bada boom).



Brother can you spare some argentum? Maybe you could drop some in my stannum cup. Then I'd be totally aurum. Never heard of any of that stuff? I'd guess you probably have, just not in the words of the long dead Latin language.

Silver (argentum), tin (stannum) and gold (aurum) are pretty familiar materials to most of us, and if you've taken chemistry you've likely used the Latin abbreviations Ag, Sn, and Au without worrying too much about the odd choices for the shortened handles of these and and a few other elements like iron (Fe for ferrum), potassium (K for kalium) or lead (Pb for plumbum).

But I've had just about enough of this silliness. All roads may have once lead to Rome (plumbumed to Rome?), but no more. It might mean reprinting a few chemistry texts, but we'll need to do that as we work to eliminate Avogadro's constant anyway.

Just to get things rolling here are my suggestions for abbrevia…

100 Years of Superconductivity

[Physicsworld.com video about superconductivity from the 2011 APS March Meeting]

Paul Michael Grant was a physicist working for IBM when his colleagues in Zurich discovered the first high-temperature superconductor in 1986. Grant, who worked for IBM's Almaden labs in California, has become a proponent of using superconductors for electricity distribution since leaving IBM in 1993.

Physicsworld.com's Hamish Johnston spoke with Grant at the 2011 APS March Meeting in Dallas about the commercial applications of superconductors. The centennial of the discovery of the superconductor was celebrated at this year's meeting.

For more, check out the original physicsworld.com article.

Yuri Gagarin & the First Orbit

Yuri Gagarin was the first human to ever enter space on top of a rocket, simultaneously becoming the first man to go into space and the first to ever go into orbit. Unfortunately, he made for a poor tourist, having no video camera on that first historic voyage. Fifty years later, one filmmaker is helping the world to see what Gagarin might have seen a half century ago.


[First Orbit Trailer]

Chris Riley, co-director of "In the Shadow of the Moon" has collaborated with the European Space Agency (ESA) to produce the experimental documentary "First Orbit" - a compilation of video shot from the International Space Station (ISS) and original Soviet video from Gagarin's flight.

"I just kind of suddenly thought 'Wouldn't it be great to film a view that Gagarin had?'" Riley said in a BBC interview. "I always remembered the sad reality of there not being any footage of it."

Italian astronaut Paolo Nespoli - already an accomplished space photo…

Music Review: Resonance: Music from the ATLAS Experiment

If music is audible mathematics, then it makes sense that people who studied a lot of math would connect through music. That's what happened at the ATLAS experiment in Switzerland where physicists, technicians, and engineers spent their free time in jam sessions when away from the world's largest particle collider (the LHC).


["The ATLAS Boogie" by the Canettes Blues Band music video]
Rock, blues, classical, heavy metal and folk: These are just a handful of the musical genres represented on the two "Resonance: Music from the ATLAS Experiment" CDs.

The CDs were recorded by employees working on the ATLAS project on the Large Hadron Collider (LHC) at CERN, the European Organization for Nuclear Research, in Geneva, Switzerland.


[Behind the scenes video on the making of 'Resonance"]
Musical numbers include both original songs and covers recorded by 19 different artists and groups including Squirrelheads in Gravy, The Collider Trio, and even piano soloist Fabi…

European Settlers Not The First To Alter American Landscape

Native Americans on the East Coast dramatically changed the landscape by farming well before the first Europeans arrived.

(ISNS) -- One of the great American myths claims that before Europeans colonists settled in North America, Native Americans existed in total harmony with nature, surviving on the renewable bounty that the continent's natural environment provided and altering little of the surrounding landscapes. They were America’s first environmentalists and the land they lived in remained unspoiled.

But that is not entirely true.

Research by scientists at Baylor University, the Smithsonian Institution, and Temple University has found that the Native Americans who lived in the Delaware Valley, the river valley that separates New Jersey from Pennsylvania, dramatically altered its terrain with their farming. They cleared forests and increased the number of floods.

“From the period 1000-1600 A.D., a few hundred years before European colonization, there was this episode of strong, mor…

Why is it so hard to find flight 447's black boxes?

The French government announced today that more bodies and wreckage from the Air France flight 447 crash off the coast of Brazil had been found almost two years after the crash. The critical pieces of the puzzle, the plane's flight data recorders - or black boxes - are still missing, however. But why are they so hard to find?

[Flight 447's vertical stabilizer (tail fin), recovered in 2009.]

The wreckage from flight 447, which crashed in the Atlantic Ocean off the coast of Brazil in June 2009, is scattered over mountainous ocean floor at depths from 12,500 - 13,000 feet, or around 2.5 miles. Though that doesn't sound very deep, especially when you consider that modern airliners often cruise at three times that height, it's far too deep for scuba divers or naval submarines to explore.

For every 33 feet you descend under water, the atmospheric pressure pushing down on you increases by 100 percent. At the surface, every person and object has 14.7 pounds per square inch of air…

Low Water Mark for Physics Buzz Team

PhysicsBuzz is sad to report today that several of the physicists who toured the decrepit Superconducting Super Collider in Texas were escorted from the office this morning. Re-posted below is an article detailing what happened:

-----

Apr 1, 10:00 AM EDT

Four Physicists Arrested in National Lab Break-in
By Flora S. Lipo

COLLEGE PARK, Md. -- A team of four physicists was arrested this morning at the headquarters of the American Physical Society (APS) in College Park, MD. Plain-clothed officers from the Department of Homeland Security entered the building around 8:30 a.m. and detained the suspects without incident. The group is charged with breaking and entering a secure government facility, destruction of government property, stealing national secrets and parking illegally. [Photo taken by a building employee as the suspects were being escorted out.]

During the APS March Meeting held in Dallas, Texas, the individuals traveled 30 miles south to Waxahachie, Texas, and entered the fiv…