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Chameleon-Like Behavior of Neutrino Confirmed
Anonymous Apcoheur writes "Scientists from CERN and INFN of the OPERA Collaboration have announced the first direct observation of a muon neutrino turning into a tau neutrino. 'The OPERA result follows seven years of preparation and over three years of beam provided by CERN. During that time, billions of billions of muon-neutrinos have been sent from CERN to Gran Sasso, taking just 2.4 milliseconds to make the trip. The rarity of neutrino oscillation, coupled with the fact that neutrinos interact very weakly with matter, makes this kind of experiment extremely subtle to conduct. ... While closing a chapter on understanding the nature of neutrinos, the observation of neutrino oscillations is strong evidence for new physics. The Standard Model of fundamental particles posits no mass for the neutrino. For them to be able to oscillate, however, they must have mass.'"
The Standard Model of fundamental particles posits no mass for the neutrino. For them to be able to oscillate, however, they must have mass.
Unless oscillation is the fundamental thing and mass is just a sometimes effect of oscillation... but then IANAP.
Moderating "-1, Disagree" is simple censorship. Have the guts to post your opinion.
How could something have mass and so weakly interact with normal matter? My understanding is that most neutrinos pass through the earth unmolested.
(insert obligatory Catholic priest joke here).
I's thought that neutrinos being massless made this possible.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
That's the way I've always understood the mass/oscillation connection too. But then I thought... wait... don't photons oscillate too? They're just coherent oscillations of the EM field; oscillating back and forth between electric and transverse magnetic in free space. If there's something different about neutrino oscillation which makes it necessary for the neutrino to travel at sublight, what is it specifically?
Does that fact that light is polarizable, has known frequencies of oscillation, and no mass (but has momentum), throw a wrench into all this claim that you need mass to oscillate? Probably not on these forums, but it still makes me pause to think about it.
I wouldn't consider the mad hatter mad. Just reality impaired. He sure can make a mean cup of tea.
Glad to oblige.
Imagine a highway. All the north-bound cars are WHITE Toyota Camrys, and all the south-bound cars are BLACK Toyota Camrys. All the cars are moving very very very fast. At a certain point in the road, workers open gates that cause the two streams of traffic to plow into each other, head on. At the crash site, common sense would tell you that pieces of Toyota Camrys would come flying out, but instead, complete vehicles of other makes and models (Honda Civics and Nissan Sentras, many others, including vehicles larger than two Camrys, like Peterbilt 18-wheelers) appear instead. After a few seconds, some of these vehicles break apart, and become other vehicles, say a Peterbilt breaks apart and becomes a Ford F-150 and two Harley Davidson motorcycles. Particle physicists make a living by crashing different streams of vehicles into each other and observing the new vehicles that come out. They've put together a list of these, like "Peterbuilt --> Ford F-150 + 2(Harley Davidson Motorcycles)". They call this list the Standard Model. This new experiment shows that sometimes, after a while, one of the Harleys suddenly changes models, say from a Fat Boy to an Electra Glide.
Hope this helps.
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
Kolmogorov complexity is defined logically, it is not an "artifact injected by humans", unless you're stating that all mathematics are an "artifact injected by humans".
The poster means that, on the tree of all theories, the ones with the smallest Kolmogorov complexity, are also the one with the highest number of branches, and therefore the ones that are most likely, by the definition of the word "likely".
This doesn't seem to have anything to do with "laziness".
I don't know of any superselection-rule -- it's possible, in theory, for the electron neutrino to have zero mass but the muon neutrino to have nonzero mass.
But then you'd have to explain why one flavor was massive while the other was massless, which has never happened before. Since there's lots of precedent for three flavors with different nonzero masses, people just figure that the neutrinos are the same way.
I don't know of any superselection-rule -- it's possible, in theory, for the electron neutrino to have zero mass but the muon neutrino to have nonzero mass.
You can't have oscillations between massless and massive states. Remember, SR says that time stands still for massless particles. If you look at the equations for neutrino oscillations, for example here, you'll see there are expressions involving both the mass squared (for the time evolution of the wavefunction), and mass difference squared, for the mixing amplitudes. So, for quantum mechanical mixing between states, you need both non-zero masses and non-zero mass differences. There may be other, weird mixing theories which don't require mass differences, but they would be quite exotic. On the other hand, mixing of particles with zero masses would violate SR, which would be highly surprising!
If I can be modded down for being a troll, can I be modded up for being an orc, or a balrog?
This car analogy was pretty awesome. Just one detail: The CNGS (CERN Neutrinos to Gran Sasso) experiment is based on slamming cars (in fact, protons) into a mountainside (or a metallic target) and seeing what comes out on the backside of the mountain (730 km away). This is where the car analogy breaks down, and the Standard Model takes over.