

Alpha Magnetic Spectrometer confirms unexplained excess of high-energy positrons - raverbashing
http://physics.aps.org/articles/v6/40

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ISL
Surprising to see six pages of text in PRL.

It's well-written paper; it'll take a few reads to really grok the
measurement. Kudos to the AMS team for sticking closely to the facts.

AMS NASA webcast will be at 1:30 PM EDT. (CERN webcast is already complete?)

<http://ams.nasa.gov/>

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richardjordan
As with the other recent anomalous results it's reassuring that there are
these unexplained results still out there. The concern of physicists (and I'm
many years removed from being one) is in pushing experiments like the LHC,
finding what we predicted and nothing more.

This points to new physics and that's a good thing. The problem with the
staggeringly successful and precise "Standard Model" is the number of hand-
tweaked variables you have to include to make it work. Absent new physics, if
this became all we could experimentally demonstrate, we'd be left with solely
anthropic reasoning (we just happen to exist in a universe compatible with our
existence).

So yay for positrons!

~~~
rrmm
The interesting thing is that more of the anomalous results are coming from
astronomical observations and in general non-collider experiments.

Colliders have been really successful where they can be applied and have given
a consistent footing to build upon, but there seems to be large areas still to
explore at the weakly-interacting end of the things.

~~~
richardjordan
Well, we're getting to energies where colliders are approaching some pretty
expensive limits and space provides much better natural accelerators for us to
study.

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breadbox
And now for your obligatory bucket of cold water:

[http://scienceblogs.com/startswithabang/2013/04/03/itll-
take...](http://scienceblogs.com/startswithabang/2013/04/03/itll-take-a-lot-
more-than-ams-to-find-dark-matter/)

TLDR: "Based on what AMS has presented, there is nothing to suggest that they
have detected any evidence whatsoever for particle dark matter.... Calling it
misleading is generous, because I personally believe it is deceitful, and it’s
a deceit that I even anticipated a few weeks ago."

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ttrreeww
Dark matter reminds me of the ether.

~~~
InclinedPlane
Proving that you know nothing of the subject other than some casual mentions
in the popular press.

Dark matter is a very coherent theory which has been confirmed repeatedly in
many different and diverse areas of study. Everything from large scale
numerical models of the evolution of the Universe to the exact nature of
ripples in the temperature of the cosmic microwave background to gravitational
lensing to galaxy rotation curves and more. It's an extremely well confirmed
theory at this point.

~~~
205guy
I don't know the history of aether theory (that spelling is easier to google),
but I bet someone wrote something equivalent to InclinedPlane's comment about
it at one time. Even if aether was contested and later disproved, the history
of science should continue to enlighten our modern views of how we as humans
interpret the universe.

There are several ways to interpret ttrreeww's comment: \- Dark matter is a
bunch of mumbo jumbo just like we know the aether theory to be. IP reacted to
this meaning. \- Dark matter is vaguely reminiscent of aether theory in that
it was built up from observed effects without knowing what the stuff actually
was. I like this one better, but we won't know if that's what ttrreeww really
meant unless we ask yo.[1]

If a statement is so short that it is easy to misinterpret, why react so
strongly to one of the interpretations?

[1] <https://news.ycombinator.com/item?id=5481430>

~~~
loqi
> I bet someone wrote something equivalent to InclinedPlane's comment about it
> at one time

Doubtful, because an equivalent statement would sport an equivalent truth
value for an equivalent statement of support. Substitute "aether theory" for
"dark matter" in InclinedPlane's comment, and his assertion of its wide
confirmation would be trivially false. Many physicists at the time _believed_
the aether theory to be true, but _confirmation_ remained (rightly) elusive,
despite very sophisticated attempts.[1]

I feel the need to point out that the periodic table was also built up from
observed effects without knowing what the stuff actually was. It wasn't the
first attempt at categorizing the elements. Mendeleev's table was special
because, like dark matter and unlike aether theory, it had positive predictive
value. It made predictions about the properties of unknown elements that
turned out to be correct.

[1]:
[http://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experi...](http://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment)

