
Have Balloons and Ice Broken the Standard Model? - extraterra
http://nautil.us/issue/65/in-plain-sight/have-balloons-and-ice-broken-the-standard-model
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klohto
Lengthy discussion:
[https://news.ycombinator.com/item?id=18081920](https://news.ycombinator.com/item?id=18081920)

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eganist
I don't know enough on this topic, so kindly pardon my ignorance, but while
I'm aware that neutrino detectors can pick up particles punching through the
ground, that's a few dozen meters of ground tops, is it not?

For a particle to survive tens of thousands of miles through dense rock and
come out the other side _and register with the detector_ makes me ask:

1\. Just how many particles are discharged by the event and/or passing through
the earth at the time of the reading?

2\. What's so special about the composition of the detector that it's able to
pick up particles that have not been stopped by the entirety of the Earth?

I'm not asking these questions dismissively. I'm keen to learn. I'm also aware
I'm making many assumptions here. Please question or contradict all of my
assumptions if possible.

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PhasmaFelis
Neutrinos are weird little things, and pass clean through any sort of matter
almost every time. The famous statistic is that you'd need a light-year of
solid lead just to block _half_ of all neutrinos.

What surprises me about this article is that catching neutrinos tunneling up
through the earth is considered surprising. I had thought that neutrino
detectors generally caught just as many neutrinos from below as from above;
the earth is essentially transparent to them.

To answer your question #2: the detector is no better than anything else at
stopping neutrinos (just as detecting their stoppage), but--even though the
chance of any given neutrino stopping anywhere in the earth is almost nil--
there are so very very many of them that the probabilities add up to a decent
number impacting within the detector.

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kstr
Neutrino detectors are mainly looking for (neutrino) events coming from below
in order to avoid noise from cosmic rays coming from above.

The surprising part is if other particles are observed coming in from below.

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empath75
This seems plausible to me. It’s something that has been hypothesized for a
while, it’s not proposing anything implausible like ftl neutrinos, and the
effect seems small enough to explain why we haven’t seen them before. It’s
very exciting.

