Physics & Mathematics

The Elegant Universe: Einstein's Dream

Tuesday, July 3, 2012
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Is The Hunt For The 'God Particle' Finally Over?

Monday, July 2, 2012
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July 2, 2012
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This image, from a sensor at the particle accelerator at CERN, is an example of the data signature a Higgs particle might generate.(CERN)

Before we get to the fireworks on the Fourth of July, we might see some pyrotechnics from a giant physics experiment near Geneva, Switzerland.

Scientists there are planning to gather that morning to hear the latest about the decades-long search for a subatomic particle that could help explain why objects in our universe actually weigh anything.

The buzz is that they're closing in on the elusive Higgs particle. That would be a major milestone in the quest to understand the most basic nature of the universe.

King Arthur had his quest for the Holy Grail. Physicists hope they are hot on the trail of the Higgs particle. You might call it the final puzzle piece, needed to complete the picture of how all the fundamental particles make up the universe.

Joe Lykken at the Fermi National Accelerator Laboratory in Illinois has been part of this quest since the early 1980s.

"Our former director, Leon Lederman, called the Higgs particle the 'God particle,' " Lykken says. "It was not meant to be a religious comment; it was meant to express our understanding of how the universe works. We think without a Higgs boson, you can't have a universe in the first place."

At the very least, the universe would be incredibly boring. That's because the Higgs particle, or Higgs boson, is supposed to explain why the atoms in the galaxies, the stars, the earth at our feet and in our bodies have mass. If they didn't have mass, we wouldn't exist as physical beings.

"We think the Higgs boson is a manifestation of the fact that the universe is filled with a force that we haven't been able to detect yet that gives other particles mass," Lykken says.

It's weird to think that particles only become massive by interacting with some invisible field. After all, we think of mass as the inherent property of an object. But that's what the so-called standard model of our universe predicts.

We may never be able to detect that mass field directly. But as you may recall from high school science, fields also come with matching particles. Electromagnetic fields, including visible light, are also manifest as abundant photon particles.

We don't see the Higgs particle, because it's incredibly unstable, "so it exists for a billionth of a billionth of a billionth of a second, or something like that, and then falls apart into other particles," Lykken says.

This brings us, at last, to that physics experiment on the Swiss-French border. The Large Hadron Collider has been banging together atomic particles at super-high energies in an attempt to produce a few Higgs particles. And scientists have been sifting through the resulting debris to see if they can find signs that Higgs particles appeared and then quickly broke apart.

Last December, the scientists there said they were seeing tantalizing hints. Now, they have a new pile of data. They are hoping to be able to say something more definitive.

"This is really the most exciting year in my career," says Matt Strassler, a theorist at Rutgers University. "And the reason it's so exciting is this is one of those very, very rare circumstances that, first of all, we know there's something to look for, and we know, whatever the answer is — whether it is there or not — it's going to be very interesting and exciting."

Thousands of physicists are waiting for the "aha" moment, whenever that might be. Drew Baden, a physics professor at the University of Maryland, says on one level, the discovery is expected, because it has been predicted for so long. But he says the physics world is like Christopher Columbus, who sailed off to the West, confident that he would eventually find the ocean's opposite shore.

"It's all theory, right? Because no one has done it," Baden says. "And then [Columbus and his men] get in their ships, and they actually make it. This is really deep."

Columbus took an abstract and unproven idea and proved it was true. Baden says that's exactly where the experiments in Switzerland are heading. They are turning squiggly formulas into actual physical things.

It's still a bit premature to declare success, "but it really looks good — people are starting to be convinced that maybe this is the new world that we're seeing," Baden says.

Finding the Higgs particle isn't like finding a speck of dirt. Nobody will ever see it directly. Scientists need to plow through huge amounts of data to be sure that the anomaly they are seeing represents an actual particle, not just fluky coincidences.

But the way things look now, sometime this year physicists will probably see enough evidence in that spray of subatomic particles to declare that they've finally found the Higgs boson.

Copyright 2012 National Public Radio. To see more, visit

Scientists Back Off, Neutrinos Were Not Clocked At Speeds Faster Than Light

Monday, June 11, 2012
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A 2009 London art installation, Super K Sonic Booum, by Nelly Ben Hayoun replicated a neutrino detector, allowing the public to ride in a boat accompanied by the physicists working on the Super-Kamiokande in Japan.(Photo: Nick Ballon)

The team of Italian scientists running an experiment called OPERA, who said they had clocked neutrinos moving faster than light, have come to terms with their findings: They're experiment does not challenge a very basic tenant of physics.

According to the New Scientist, the researchers made the admission during the Neutrino 2012 conference in Kyoto on Friday. Neutrinos, the scientists said, move very close to the speed of light.

And they're also shape shifters. We'll let the New Scientist explain:

"Neutrinos come in three flavours: electron, muon and tau. Several experiments had seen evidence for neutrinos spontaneously switching, or oscillating, from one type to another. Those oscillations proved, to many physicists' surprise, that the supposed massless particles must have some infinitesimal mass, and offered a route to explaining why there is more matter than anti-matter in the universe.

"Before OPERA, all the evidence for neutrino oscillations came from disappearances: detectors would end up with less of a certain type of neutrino than they started with, suggesting some had morphed into other flavours. Then in 2010, OPERA found the first tau neutrino in a beam of billions of muon neutrinos streaming to the Gran Sasso detectors from CERN. The discovery was a big deal at the time, but the team said they needed more tau neutrinos to make it statistically significant."


Copyright 2012 National Public Radio. To see more, visit

Physics in the Eye of the Beholder

Tuesday, March 13, 2012
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March 13, 2012art-physics
Groningen by Metro Centric/Flickr

Walter Lewin
, Professor of Physics, Emeritus at MIT, talks about what art and physics have in common: a spirit of pioneering that has a major impact on how we percieve the world.

Here is an MIT World video with Professor Lewin on viewing 20th Century Art through the lens of a physicist.

How the Hunt for Alien Worlds will Revolutionize Life on Earth

Friday, March 9, 2012
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March 8, 2012

BOSTON — Are we alone? In his new book, The Life of Super-Earths: How the Hunt for Alien Worlds and Artificial Cells Will Revolutionize Life on Our Planet, Harvard planetologist Dimitar Sasselov tells the story of an unprecedented convergence in astronomy and chemistry that may bring us closer to answering this question, as well as unraveling the secrets of the origins of life.

Sasselov studies super-Earths (rocky planets that orbit stars), as candidates for conditions that may be hospitable to life. In this video, taken from a longer lecture at Harvard Bookstore, Sasselov explains how recent advances are allowing astronomers to learn more about distant planets than ever before. Astronomers can now measure not only the size and temperature of planets, but also discern their chemical makeup — but how is it possible to know such detail from so far away? Simultaneously, chemists are exploring the kinds of biochemistries that these planets could possibly support.

Not X-Ray Vision, Terahertz-Ray Vision

Wednesday, February 15, 2012
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Feb. 15, 2012
Light dispersion of a mercury-vapor lamp with a flint glass prism, on Wikimedia Commons

Jim Butler, a retired scientist from the US Naval Research Labratory, talks about the possibile uses of a tereahertz laser.

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