Rogue antimatter found in thunderclouds

Publish too early and you get people assuming that you're a crank because you haven't done the research yet.

If the most reasonable explanation for the data is an error in measurement...

It mostly depends on how close to tenure they are, and how controversial the data is.

e.g. Dan Shechtman, who recently got a nobel for his work in crystallography, was an outcast for a long while because his data did not fit with the prevailing model - to the point that people in his lab refused to peek through his microscope eyeviewer because what he said they will see there should not have been possible.

Read http://www.theguardian.com/science/2013/jan/06/dan-shechtman... and also http://motherboard.vice.com/read/quasicrystals-are-natures-i... (it's about a lot more, but also talks about Shechtman's history)

There are a few other cases like this: Robin Warren (Ulcer/Helicobacter connection), Barbara McClintock ("Jumping Genes"). The farther back they are, the harder it is to get the real story, but unfortunately Shechtman's story is far from unique.

I just completed a degree in physics from his university, actually. I can think of a few reasons:

1. He wanted to be 100% sure about the data and not rush it, especially if it could be an error with the instruments

2. He has funding for other projects that needed to be worked on in the mean time, and didn't have a lot of time to devote to this work (this can make #1 take longer)

Yes, in fields where precision is prized above speed, experimentalists can sit on controversial results for a long time looking for the cause of a discrepancy.

If I tell you that General Relativity is fine, and Einstein's a little more right, you might be impressed and give me a job. If I report that there's something unexpected about gravity at distances less than a millimeter, and I'm not absolutely correct, it might end my career.

Irreversibly-unblinded blind experiments are a technical way to solve this problem (I just unblinded my thesis work a week ago. Gravity turned out fine, after a clerical glitch.), but it does not solve the social stigma that can be attached to someone who has made a measurement ultimately found to be incorrect.

Depends on many things, but if the data appears "controversial yet conclusive" then you investigate more deeply until you have ruled out just about anything else. Long time ago, I was part of a research team that sat on a 3.5 sigma result that only got stronger when we got more restrictive with the data set. We ran for two more years looking for other explanations. I was in grad school and could only think "why don't we publish?!?!" but the more experienced folks won out and upon further review, no Nobel Prizes were awarded and the reputations and funding remained in place. I think the adage "you only get to cry wolf! once" applies here.

Darwin waited 20 years, and only published after another naturalist was about to publish the same theory.

Never would have thought the A-10 could become an instrument of science

Positrons are way more common than that, i.e. only in the early universe, black holes, particle accelerators. They are emitted in a kind of radioactive decay, and are the basis of PET scanners.

Thunderstorms can the thought of as being driven by one of nature's particle accelerators. The electric fields in thunderstorms can run up to at least 100 kV/m and maybe more, so getting potential drops well into the mega-volt range over relatively short distances is not too difficult: http://science.ksc.nasa.gov/amu/journals/jamc-2008.pdf

Electron-positron pairs require an energy of just over 1 MeV to be created (the energy of a single electron charge dropping through a potential of 1 MV). So there is more than enough energy kicking around to generate pairs fairly copiously (positrons are always produced with a companion electron in this kind of process, although they may be produced alone in certain types of radioactive decay.)

The interesting part of this work is it seems there was a large volume where there were a lot of positrons, and the specific mechanism capable of producing that situation is not known. Really interesting science in an extreme and transient environment!

Bananas are a weak source of antimatter [0]

[0] http://en.wikipedia.org/wiki/Potassium-40

Some antimatter particles are easy to make locally. For example many radioactive isotopes decay by positron emission (also named positive beta decay). http://en.wikipedia.org/wiki/Positron_emission Most of the times the positron just collides with an electron and emits a pair of 511eV photons.

For example, this is applied in a common medical procedure: Positron emission tomography (PET) http://en.wikipedia.org/wiki/Positron_emission_tomography

It's the large volume at high positron density that seems to be the new observation that can't be explained by what we know about positron production in thunderstorms currently.