Physicists Say Speed-of-Light-Breaking Neutrinos Would've Lost Their Energy Along the Way

Another day, another wrinkle in the year's biggest physics story

By Clay Dillow

The Loading Station at OPERA CERN

Last week’s bombshell physics news--those superluminal neutrinos that CERN’s OPERA experiment clocked moving faster than the speed of light--are already getting the rigorous vetting that OPERA’s researchers were hoping for. And some physicists are already rejecting the notion that CERN’s neutrinos broke the cosmic speed limit outright. A paper posted late last week, titled “New Constraints on Neutrino Velocities,” argues that any particle travelling faster than light would shed a great deal of its energy along the way.

And since that didn’t happen, those neutrinos couldn’t have travelled faster than light. Case closed.

So let’s go a little deeper here. The physicists behind this assessment, Andrew Cohen and Sheldon Glashow of Boston University (Glashow has a Nobel under his belt, so these are no middling minds), ignore the debate over whether or not it’s possible for a fundamental particle to outpace the speed of light, and instead look directly at the OPERA neutrinos themselves.

In looking at the neutrino beams that landed at Italy’s Gran Sasso laboratory, Cohen and Glashow found that it was about the same as the beam emitted from CERN in Switzerland. That is, the neutrinos were of roughly the same high-energy flavor at their origin and at their destination.

But that’s not possible if these neutrinos surpassed the speed of light, they say. A neutrino achieving superluminal speeds would emit other lower energy particles--most likely an electron-positron pair-- along the way, and in doing so lose a good deal of its own energy. So the neutrino beam arriving at Gran Sasso should have been “significantly depleted” of high-energy neutrinos.

But this was not the case. Which means, they say, that in all likelihood these neutrinos never achieved superluminal speeds. The anomaly is an error in the data or measurement of the speed, or some other brand of misunderstanding or miscalculation.

Which makes a certain amount of sense, writes Steve Nerlich over at Universe Today over the weekend. Neutrinos do move very fast, straight through the Earth (neutrinos don’t interact much with normal matter), relying on GPS time-stamping and other methods of man-made measurement that are very precise but certainly not infallible to determine time and distance traveled.

And it’s not like these neutrinos were clocked doubling the speed of light or something like that--the difference is 60 nanoseconds. That’s another way of saying that the neutrinos in question are thought to have traveled at 1.0025 times the speed of light. That’s certainly a small enough margin to be explained away by some kind of measurement error.

Still, the jury remains out on this one, and we certainly don’t want to dismiss a perfectly good game-changing science story just because it seems hard to reconcile with the status quo. After all, if OPERA’s result turns out to be confirmed it is going to completely reorient physics as we know them. More on this as it develops.

[SciAm]

ALMA, the World's Largest Radio Telescope, Grabs Its First Images

By Rebecca Boyle

ALMA's First Image This is ALMA's first image, showing the Antennae Galaxies in two different wavelength ranges. The image was captured during the observatory's early testing phase, using only 12 antennas working together — the array will eventually have 66. European Southern Observatory

The world’s largest astronomical facility has opened its eyes, turning nearly two dozen antennae toward the heavens to study the building blocks of the cosmos. The Atacama Large Millimeter/submillimeter Array consists of 20 radio antennae for now, but will contain 66 by 2013, giving it a higher resolution than the Hubble Space Telescope.

Appropriately enough, the first images captured the Antennae Galaxies, a pair of colliding galaxies replete with stars and stellar nurseries. ALMA’s 39- and 23-foot dish antennae can resolve areas of dense, cold gas that other telescopes could not detect.

ALMA sits in the high Chilean desert, about 16,000 feet above sea level and above much of the interfering atmosphere. These pictures were made with 12 telescopes situated relatively close together; science observations during the next few months will be even clearer.

Closer-situated antennae yield a wide field of view, so astronomers can search for items they want to study in more detail. Moving the antennae farther apart provides a narrower focus, like using a finer lens on a regular telescope. Instead of tunable knobs, ALMA has 192 separate antennae pads for the huge dishes to be moved around.

Astronomers submitted more than 900 research proposals for the telescope’s first 9 months of observations, which the European Southern Observatory whittled down to about 100. A few key subjects:

• A nearby star system called AU Microscopii, just 33 light-years away, with an infant star harboring a ring of planetisimals;
• The dusty disk surrounding HD142527, a young star 400 light-years away, which has enough material to make a dozen Jupiters;
• and the great Sagittarius A, the supermassive black hole at the center of the Milky Way.

ALMA observes light at millimeter and sub-millimeter wavelengths, allowing observations of the farthest and oldest phenomena in the observable universe. It’s powerful enough to study the cold, dark remnants of exploded stars, including the first stars, which died a few hundred million years after the Big Bang — that’s an era known as the cosmic dawn.

While this is all going on, more of the 100-ton antennae will keep being added until the observatory is complete sometime in 2013.

Antenna Network Spies Antenna Galaxies: This image combines data from the Hubble Space Telescope and the ALMA network. Appropriately enough, it depicts the Antennae Galaxies, a pair of distorted colliding spiral galaxies about 70 million light-years away in the constellation Corvus (the Crow). ALMA, the world's most complex ground telescope, is an array of radio antennae.  European Southern Observatory

[ESO]

Nanorockets Could Deliver Drugs Within the Body

By Julie Beck

Nanorockets in Your Body Wikimedia Commons

The idea of nanorockets zipping around your body delivering drugs sounds a little Osmosis Jonesy, but German researchers have developed a less toxic fuel that might make that possible.

Replicating a tiny rocket inside the body brings some, well, health concerns. And those are valid; traditional rocket fuels like hydrazine are extremely toxic, highly flammable and dangerously unstable, all of which make it a pretty lousy candidate for a substance you'd like spurting out of a tiny rocket inside your body. Instead, the research team made rolled up metal nanotubes coated with platinum, so that platinum side would be on the inside, and put them in a weak hydrogen peroxide solution. The platinum catalyzed the peroxide, speeding its decomposition into water and oxygen, which forced gas bubbles out of the tube, generating thrust, even in bodily fluids such as blood, saliva or urine.

The rocket can travel up to 200 times its own length per second, and the researchers are able to control its speed by changing the temperature of the fluid. They can also steer the nanorocket using a magnetic field, to precisely direct the drugs to where they are needed.

While using peroxide is infinitely better than toxic rocket fuels, at 0.25 percent peroxide, it's still not completely safe. Researchers would like to dilute the solution further, or even better, create rockets that can be powered by glucose, or another substance already in the body.

Check out the rockets in action in the video below:

[New Scientist]