Research duo calculate possible number of WIMPs striking our bodies

Apr 11, 2012 by Bob Yirka report
Interactions of 60 GeV WIMPs on various nuclei in the human body. Image from arXiv:1204.1339v1

(Phys.org) -- Katherine Freese and Christopher Savage from the University of Michigan and Stockholm University respectively have embarked on a whimsical bit of physics research. They’ve been estimating the number of Weakly Interacting Massive Particles (WIMPS), thought by some to be instances of dark matter; that stuff that fills in the holes in physics theories that can’t be explained any other way, that likely strike the human body on a yearly or even minute by minute basis. They have found, as they describe in their paper they’ve uploaded to the preprint sever arXiv, that in their estimation, billions of WIMPS pass through every human body on Earth every second. But only a small fraction of those actually hit something such as the nuclei of an oxygen or hydrogen atom. They say most assumptions about dark matter would put the collision rate at something like thirty times a year. If new data is taken into account however, they suggest the hit rate could be closer to 100,000 a year, or one every minute or so.

Dark matter is a touchy subject in physics. No one has found any proof that it really exists, yet countless theories rest on its existence because there has to be something there to explain huge discrepancies in basic physic theories involving gravity and mass. Why for example, does the entire mass of a galaxy add up to less than the amount necessary to exert the gravity effects seen that keep its structure intact? Physicists say it’s because there is a quantity of mass that cannot be seen or measured that makes up the difference, so-called . But if that is so, then it stands to reason it must be here around us all, every day, moving through everything we can see, including our own bodies. And that’s why Freese and Savage turned to math to try to find out how much there should be, if it does indeed exist.

Their calculations are based on findings of researchers working with particle detectors buried under mountains in various locales that go by names like DAMA, CRESST and CoGeNT. There scientists have set up huge pools of liquid materials with crystals that light up when struck by neutrinos and other sub atomic particles. Such detectors can theoretically be used to detect the presence of dark matter particles as well by measuring the recoil in observed strikes, and one of them, DAMA claimed to have done so at one point, but those results were not reproducible by others.

Frees and Savage used such measurements to make their calculations, which while interesting, don’t appear to actually add much to the understanding of dark matter or offer any new clues as to whether it really exists. But their research does bring up some obvious questions such as, what happens to our bodies when (if) they are struck by such particles, and is it all a part of some of the areas in biology we really don’t understand, such as how life came to exist in the first place or how does a lump of grey organic matter give rise to consciousness?

Explore further: Physics professor publishes exact solution to model Big Bang and quark gluon plasma

More information: Dark Matter collisions with the Human Body, arXiv:1204.1339v1 [astro-ph.CO] arxiv.org/abs/1204.1339

Abstract
We investigate the interactions of Weakly Interacting Massive Particles (WIMPs) with nuclei in the human body. We are motivated by the fact that WIMPs are excellent candidates for the dark matter in the Universe. Our estimates use a 70 kg human and a variety of WIMP masses and cross-sections. The contributions from individual elements in the body are presented and it is found that the dominant contribution is from scattering off of oxygen (hydrogen) nuclei for the spin-independent (spin-dependent) interactions. For the case of 60 GeV WIMPs, we find that, of the billions of WIMPs passing through a human body per second, roughly ~10 WIMPs hit one of the nuclei in the human body in an average year, if the scattering is at the maximum consistent with current bounds on WIMP interactions. We also study the 10-20 GeV WIMPs with much larger cross-sections that best fit the DAMA, COGENT, and CRESST data sets and find much higher rates: in this case as many as $10^5$ WIMPs hit a nucleus in the human body in an average year, corresponding to almost one a minute.

via Arxiv Blog

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User comments : 9

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Kinedryl
Apr 11, 2012
This comment has been removed by a moderator.
Yellowdart
Apr 11, 2012
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mikeiavelli
3.7 / 5 (7) Apr 11, 2012
Please M. Yirka, do not write things like these:

"But their research does bring up some obvious questions such as, what happens to our bodies when (if) they are struck by such particles, and is it all a part of some of the areas in biology we really dont understand, such as how life came to exist in the first place or how does a lump of grey organic matter give rise to consciousness?"

It makes your post look amateurish. So much so, that in fact it lead me to check your bio, where I found out you were a Computer Scientist with a MS in Information Systems Management. I value and respect your interest in Physics. But please, keep your personal thoughts for yourself. PhysOrg is not the right platform to express such remarks.
Terriva
1 / 5 (6) Apr 11, 2012
In dense aether model the dark matter is mostly formed with low energy neutrinos, which are collected at the gravitational shadows during solar eclipses and planetary conjunctions (or even during new Moon period). The increased density of neutrinos may make the human psychic less stable, which is why the ancient astrologers attributed the wars and various social revolutions just to the planetary eclipses.
StarGazer2011
1 / 5 (5) Apr 11, 2012
So how many of them would be in the middle of the Sun; trapped by gravity and increasing number until ... boom!
Deathclock
3.3 / 5 (7) Apr 11, 2012
So how many of them would be in the middle of the Sun; trapped by gravity and increasing number until ... boom!


No... just, no... /sigh
vacuum-mechanics
1 / 5 (4) Apr 11, 2012
In the paper,
Dark matter is a touchy subject in physics. No one has found any proof that it really exists, yet countless theories rest on its existence because there has to be something there to explain huge discrepancies in basic physic theories involving gravity and mass.

But if that is so, then it stands to reason it must be here around us all, every day, moving through everything we can see, including our own bodies.
.

By the way, it is interesting to note that according to an unconventional concept we could indeed understand what really the dark matter is, in the paper below.

http://www.vacuum...id=14=en
StarGazer2011
1 / 5 (1) Apr 12, 2012
So how many of them would be in the middle of the Sun; trapped by gravity and increasing number until ... boom!


No... just, no... /sigh


The argument is that WIMPS dont interact with normal matter, so they wont be forced out of the Sun by the normal electromagnetic effects (which dont touch them), but they do have gravity. So why wont they just collect in the middle of the Sun (and all other stars) until they overcome the explosive force of fusion reactions and cause the star to collapse?

Your little smug nonsense notwithstanding, I think you will eventually figure out that this is a pretty basic flaw in the non-self anihillating WIMP idea. Or perhaps you are only smart enough to feign knowledge?
Deathclock
2.3 / 5 (3) Apr 12, 2012
Neutrinos are weakly interacting particles and they stream out of the sun by the countless trillions per millisecond... that's why I commented the way I did...
StarGazer2011
1 / 5 (1) Apr 12, 2012
Hey another question for the DM entusiasts...
If DM doesnt interact with electromagnetism, how could it gain any heat? Wouldnt it be totally cold due to its inability to absorb radiative energy?

@Deathclock; yeah but neutrinos have negligable mass, DM by definition has more mass than all other matter, you are comparing snowflakes with whales. Also neutrinos are generated in fusion reactions, so they are necessarilly moving AWAY from the star, whereas DM would be moving towards it. Furthur, neutrinos are weakly interaction, WIMPS are theorietically NON INTERACTING, big difference. So I dont think your analogy is apt.

The problem of supernovas is the whole reason its postulated by some theorists that WIMPS are their own anti-particle, its only to sidestep the rather obvious problem with accrual in stars. But it causes the problem that being their own anti-particle we should see photons from them colliding in galactic collisions, but we dont. WIMPS dont work.
mosahlah
Apr 15, 2012
This comment has been removed by a moderator.
Terriva
not rated yet Apr 15, 2012
The Occam razor is as simple as that: for what we do actually need the WIMPS? Aren't neutrino itself able to explain the particle properties of dark matter? (I'm not talking about gravitational and force effects, which these particles don't explain anyway).

The dark matter crisis: falsification of the current standard model of cosmology

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