
What are WIMPs, and what makes them such popular dark matter candidates?  - dnetesn
http://www.symmetrymagazine.org/article/july-2015/miraculous-wimps
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cgriswald
I really don't understand how they interact.

Is it because they are unaffected by electromagnetism that they seldom
interact with each other despite being gravitationally attracted to each
other? It seems given the sheer amount of it, that the universe should be
taking a radiation bath from the past history of insane amounts of dark matter
anihilating.

If they don't interact often, then why isn't the Earth's core filled with dark
matter?

I'm also curious what particles they decay into.

Also, read this just the other day: [http://www.nature.com/news/did-dark-
matter-kill-the-dinosaur...](http://www.nature.com/news/did-dark-matter-kill-
the-dinosaurs-1.14839)

/ramble

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simcop2387
From what I understand about that (probably wrong):

1\. That's about correct. They don't interact at all with electromagnetism so
they'll give off no photons or radiation to be detected from that at least.
They're not normal baryons so they shouldn't decompose into alpha or beta
radiation either. I don't think they have an reactions that would cause
anihilation of particles like antimatter and matter. Dark matter isn't
antimatter, not sure that you've made that mistake but I've talked to other
people who have and once they realized that it made much more sense.

2\. Who would you say it isn't? From what we do know it's affected by gravity
and doesn't interact with normal matter or photons. It could be passing
through you without you noticing at all. That's one of the reasons that for a
long time neutrinos were a big candidate for dark matter because they really
don't react with anything at all most of the time (except time apparently).

3\. As am I, assuming they decay anyway.

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letitgo12345
Earth's core cannot be filled with any significant dark matter I think because
we know its composition and the calculated weight matches well with the
gravity we experience.

Dark matter doesn't collide w/ other non-dark particles usually so it cannot
lose momentum so any dark matter would just pass through Earth.

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darkmighty
Correct, Earth formed through accretion of a disk -- all which happen due to
friction. If you have no friction and the velocities of particles are
isotropic, then you should get something like a uniform cloud of particles
(instead of a protoplanetary disk, which later condenses in planets). I guess
the same dynamics apply on the scale of galaxies, which should explain the
violation of the expected rotation curve.

It should still be possible that those weakly interacting particles would be
captured by some body; if there is enough material (plus some other
assumptions?) however, they should behave more like a almost uniform fluid
(and not lumps like moons or planets), making it undetectable at small scales.

It'll be interesting to see how this hypothesis pans out.

