Mirror neutrons all over the science news

skydivephil

This paper is getting splashed all over the science news

heres the arxiv version:
http://arxiv.org/pdf/1203.1035.pdf

heres the Physics world version:
http://phys.org/news/2012-06-neutron...lel-world.html

They seem to be claiming 5 sigma , any thoughts? Less prosaic explantions?

Drakkith

Interesting, but I would cast my vote on some sort of decay mechanism or something before I put it on mirror particles.

billa12

I am not very experienced in physics but have a few questions.

How and when will they test for this?

Is this likely to be true and what is the percentage of a 5 sigma event?

Are there multiple universes or only an additonal universe plus are own? If there is only one additional universe what would it be like?

Mark M

The sigma scale refers to the percentage chance that the result can be reproduced by another physicist. The 'parallel worlds' are their explanation for the phenomenon. The confidence level is in the experiment, not in the theory that attempts to explain it. Sigma 5 is the highest possible score of statistical reliability.

billa12

I am having trouble understanding the experiment. Can someone explain it to me? I am not very knowledgeable in physics.

Chronos

The assumptions used appear to be vulnerable to criticism. The validity of multiverse math does not mean it is physically meaningful.

TrickyDicky

I had never heard about the neutron anomalous losses in the presence of magnetic field,maybe someone could expand on it but after reading the paper I think is a bit of a stretch to go from that anomaly to the parallel universe and mirror stuff they propose, and I didn't understand how a parallel universe can explain dark matter, which seems to belong to our universe.

mfb

6 sigma would be better. And 7, 8, ..., too, of course.
There is nothing magical happening at 5. It just marks a region where random fluctuations become really rare, and measurement errors and real effects become more likely in comparison.

I think it is another case for this xkcd comic.
It is easy to calculate some asymmetry (page 3, left side in the publication). But finding all sources of asymmetries in the experiment is the tricky part. If you just measure asymmetries, you can find some nearly everywhere.

Reptillian

I'm not sure I completely understand what they discovered...is it that neutrons decay faster in magnetic fields?

I swear that modern particle physicists are in a competition to outcrazy each other's explanations. What ever happened to being content with simply describing a phenomenon? Enough with the wild hypothesizing already...

At the rate we're going, this will be seen by some as a viable scientific hypothesis in a few years:

"Perhaps all the gravitons and graviolies that are constantly popping into and out of existence scattered off of one of the many types of neutrino fields that fill our universe and imparted momentum to the neutrons through reversed time asymmetry. This caused the neutrons to be absorbed by a quantum singularity that only exists in one of the 8 additional curled up microscopic dimensions we can't observed. No extra universes needed."

skydivephil

... lol

ImaLooser

There is no highest possible score of statistical reliability.

billa12

"earth maybe possesses a mirror magnetic field on the order of 0.1 Gauss" How long would it take to test for this? If the earth doesn't possess a mirror magnet field, does that make the parallel universe theory proven wrong? And just a mathematical artifact?

twofish-quant

I'm not too impressed by the paper. It looks like a theorist with a pet crazy theory that happens to find some observational result that fits his pet crazy theory. I think it's more likely that there's some alternative explanation for the results.

One thing that makes me suspicious. I'm always extremely skeptical when someone uses data to make a conclusion without people on the original team that collected the data as either a coauthor. The reason I'm skeptical is that having one of the original data collection people involved can have someone tell you when what you've measured is "something silly" (i.e. well of course you'll get those results, because we had a video camera that generated radio frequency static.)

billa12

I am not to impressed either. But how long would it take to confirm or deny the mirror magnet field around the earth?
And how long would it take to retest the quicker decay of the neutron by magnetic field? And if there is no mirror magnetic field does that mean the parallel universe theory is finished?

Reptillian

I'm still not understanding what they mean by neutron losses in the paper. Are they referring to the neutron decay, or to the escape of neutrons from the ultra-cold trap via quantum tunnelling? Do they mean that neutron decay seems to be magnetic field dependent, or that escape from the trap is field dependent? I guess I'm confused...is it just me, or do they jump right into the math of mirror universes without explaining the physics of the situation adequately? Are they saying that neutrons are disappearing from the trap that can't be accounted for via neutron decay or quantum tunnelling, so they must be escaping to to a parallel universe? Because if so, that's crazy.

billa12

Sorry for annoying everyone but how long would it take to test to confirm the results of the experiment?

And if the results stand up and all other explaination can't be explained does that mean that the mirror particles exist or are there many explainations possible even if scientist can't figure out what is causing the results?

Chronos

The mirror explanation is way too exotic. There is surely some other explanation that does not require a pencil standing on its point.