Neutrino Data Could Spell Trouble For Relativity

Science News has an exploration of the deeper implications of neutrino oscillation, one experimental confirmation of which we discussed last month. "The new findings could even signal a tiny breakdown of Einstein's theory of special relativity. ... MINOS [for Main Injector Neutrino Oscillation Search] found that during a 735-kilometer journey from Fermilab to the Soudan Underground Laboratory in Minnesota, about 37 percent of muon antineutrinos disappeared — presumably morphing into one of the other neutrino types — compared with just 19 percent of muon neutrinos. ... That difference in transformation rates suggests a difference in mass between antineutrinos and neutrinos. ... With the amount of data collected so far, there's just a 5% probability that the two types of particles weigh the same."

Comments

CPT = Lorentz Invariance

[SciBrad]

If I recall correctly CPT presumes the correctness of Lorentz invariance. And Lorentz invariance is one of the bedrocks of relativity. In other words CPT comes about from assuming your theory is Lorentz invariant and if CPT were violated it would mean Lorentz invariance is violated as well (check out Physical Review Letters 89: 231602 by Greenberg, O.W, which shows CPT violation implies Lorentz violation).

Re:CPT = Lorentz Invariance

[JoshuaZ]

It's a lot easier than tossing out your beloved theory or trying to build it up from scratch based on solid scientific evidence to support each individual tenet. I think the latter is what needs to be done, but it will take time. We need to re-figure out what we know absolutely. IOW, what aspects of special relativity are not contradicted by a CPT violation? If the Lorentz Transformation is called into question then so is science fiction's much beloved time dilation And what about the Twins Paradox? Yikes.

Time dilation has been observed in a number of different contexts, most famously by putting atomic clocks on airplanes and measuring the resulting slow down as they fly around the globe. Even if SR fails, time dilation is still an experimentally verified fact.

Re:CPT = Lorentz Invariance

[TapeCutter]

"Time dilation has been observed in a number of different contexts"

Indeed! Without taking time dialation into account GPS locations would systematically drift about 10km/day.

CPT Symmetry

[DrJimbo]

The fine article said:

If the interactions of particles are thought of as a movie, CPT symmetry requires that whatever physics occurs during the show must be the same whether the film is run forward or backward (time), viewed through a mirror (parity) and repopulated with each particle being replaced by an antiparticle (charge).

This is unclear at best. CPT symmetry says that when the film is run backward AND seen through a mirror AND all particles are replaced with the anti-particles (and vice versa) then the physics should be the same.

If you change just one, for example by running the film backward but without the mirror or the the particle exchange, or if you change two, for example, running the film backward and with the mirror but no particle exchange, then the physics will change.

Re:statistics fail

[Parlyne]

The correct statistical statement here would be that an experiment like this one would show a splitting between particle and anti-particle properties at least this large 5% of the time even if there were no difference at all.

Re:I think I had an astronomy prof that talked abo

[ultranova]

That a theory is just a tool for understanding and predicting reality.

But a theory is more than just that, it's a mental model of reality, the context for sensory input. Einstein's General Relativity and Newton's Laws of Motion are fundamentally different: Newton took time and space to be a passive background, while Einstein made spacetime an active participant in events. The two theories don't just differ a little bit on their results, they represent fundamentally different ways of looking at reality.

But in a way your professor was right: a theory is "just a" tool for understanding reality, in the same way as you brains "just" allow you to think.