# World's most sensitive dark matter detector set up

Discussion in 'Physics & Math' started by arauca, Jul 15, 2012.

1. ### chingluValued Senior Member

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1,637

" This is a lie. No one has demonstrated that dark matter does not interact with the weak force. "

Let you be taught.

As usual you completely fail to understand what you've been told. This isn't even something a layperson might struggle with (as might be the case with relativity or countability), it's very simple. Dark matter doesn't interact electromagnetically with anything.

AN Post #13

I assume you understand you understand the electo-weak force is the weak force but I am not so sure about AN.

So, you are instantly failed.

That is a lie. If dark matter has only mass and no interactions, it could have a mass a million times as large as a proton and never be detected via interaction with electrons.

Can you explain exactly how something like dark matter that occupies so much of the universe will not interact with fellow mass particles like the electron when both species derive their mass from the same Higgs interaction and all other mass species interact?

Show me the equations to support your absurd assertion. Otherwise, back down.

3. ### rpennerFully WiredRegistered Senior Member

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4,833
AlphaNumeric's post #13 tends only to strengthen my position and weaken yours, because he gave an example of a known particle which interacts only via the weak force and not electromagnetism.

No -- the electroweak theory is a unification of electromagnetism and the weak force in a common frameworks, presently described by distinct bosons for electromagnetism $(\gamma)$ and the weak force $( W^{\tiny \pm} \; \textrm{and} \; Z^{\tiny 0})$ while in the electroweak era, they would be described by different bosons $(B^0 \; \textrm{and} \; W^{\tiny 3})$. Since this isn't the electroweak era, the electroweak symmetry is badly broken with $\gamma$ massless and $Z^{\tiny 0}$ not.

Electroweak interaction = 電弱交互作用 (roughly Electricity-Weak-Interaction-Effect)
Electroweak era = 電弱時期 (roughly Electricity-Weak-Time-Phase)
neutrino = 中微子 (roughly "neutral tiny particle")
WIMP = 大质量弱相互作用粒子 (roughly "Large-Mass Weak Mutual Effect Particles")

I never said that they would never interact -- I said it was ridiculous to assume that every model of dark matter would require the electron to not be stable when we have models with dark matter candidates which do not render the electron unstable. I said if it did not interact via the weak force (still a viable option) that it could be many times the mass of the top quark and still not affect the stability of atoms to a measurable extent and that I presented equations to demonstrate this point.

5. ### AlphaNumericFully ionizedRegistered Senior Member

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6,697
I didn't say anything of the sort! Please don't utterly misrepresent what I said.

The MSSM proves your assertion false.

No, we didn't say that. Dark matter can interact via the weak force, hence why neutrinos were initially suggested as the source of dark matter.

No, you need to stop ignoring what we say and then lie about us.

You've been given enough opportunities to discuss this. You've now repeatedly misrepresented us, either by malice or ignorance. If you post in this thread again you'll be given a warning, as you're adding nothing but noise. Yes, a discussion on dark matter would be interesting. Unfortunately you cannot provide discussion, as you're incapable of a rational back and fore.

7. ### chingluValued Senior Member

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1,637
What we are trying to do here is some up with a viable candidate to explain dark matter. You can't claim you know how this works and I can't either.

So, I am trying to list the properties and truths that I know.

1) This particle either has mass or it does not.
2) If the particle has no mass, then it needs to explain the gravity stimulation through the stress energy tensor. But, it does not interact with the normal forces. So, that path is a dead end.
3) If the particle has mass, then one would think it would make the electron unstable just like enough neutrons would. But, electrons are stable. So, one might claim somehow claim mass is different for this particle. However, under the standard model, mass is derived from Higgs and thus mass must have the same properties of interaction otherwise, Higgs arrives at two different conclusions given the same logic, which is a contradiction.

Now, MSSM proves nothing.

Again, this theory has unacceptable consequences.

The MSSM imposes R-parity to explain the stability of the proton. It adds supersymmetry breaking by introducing explicit soft supersymmetry breaking operators into the Lagrangian that is communicated to it by some unknown (and unspecified) dynamics. This means that there are 120 new parameters in the MSSM. Most of these parameters lead to unnacceptable phenomenology such as large flavor changing neutral currents or large electric dipole moments for the neutron and electron. To avoid these problems, the MSSM takes all of the soft supersymmetry breaking to be diagonal in flavor space and for all of the new CP violating phases to vanish.

http://en.wikipedia.org/wiki/Minimal_Supersymmetric_Standard_Model

8. ### chingluValued Senior Member

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1,637
Your equations are not sufficient to explain electron stability.

You not only must calculate the mass of this unknown particle but also the number of them.

If it is the case that dark matter is the percentages I presented, then the odds are in favor of electron instability to an almost 100% degree.

If it is the case that dark matter is only in the 20% range as you suggested, then you have not proven by your equations that electrons are stable.

In addition, we do not even need an electron knocked from the atom as we all know from the photoelectric effect.

Hence, by your equations, we would see random electrical currents that we cannot explain nor see.

You therefore have not proven your position.

9. ### AlphaNumericFully ionizedRegistered Senior Member

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6,697
You couldn't let it go, could you? You repeatedly demand people provide you with X, Y or Z but when they do you ignore them. And when people ask you to provide something you ignore them. It's hypocritical and it makes reasonable discussion with you impossible. I told you not to post in the thread because you offer nothing but noise but you did anyway. Twice. You've been asked multiple times to demonstrate the electron necessarily becomes unstable and you've failed. You've been provided with an example of a model with massive particles but a stable electron, the MSSM, and all you could do is quote Wikipedia and ignore it. As I said, you're getting a warning.

I won't be locking the thread because it's an interesting topic. I suggest to everyone else to ignore chinglu's posts above this one. If he posts again then he'll get a holiday.

10. ### chingluValued Senior Member

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1,637
Go ahead ban me. I will posts the facts from Harvard.

The dark matter particle is an open question in physics. For you to claim you know the answer implies you are not intelligent. Now, can you refute Harvard?

What is Dark Matter?

There is much more than meets the eye. In fact, most (83% in the latest estimate) of the mass of the universe is made of invisible matter, which we call the Dark Matter. We have known this since the mid-20th century because, although the Dark Matter is invisible, it exerts gravity to the visible matter and affects their behavior. Recent studies of gravitational lensing, in which the light from very far galaxies are bent by the gravity of the intervening matter, have left virtually no doubt about the existence of the Dark Matter.

But then, what really is the Dark Matter?

We don't know.

http://www.hepl.harvard.edu/darkmatter/

I suggest anyone reading this thread ignore any post that claims to fully understand the properties of dark matter when Harvard University does not even know.

11. ### rpennerFully WiredRegistered Senior Member

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4,833
There you have it. Everything from post 6 on is Chinglu's chip on his shoulder and inability to read posts 1-5. Thus another thread is derailed through one member's aggressive ignorance and arrogant delusions of competence.

This thread was originally about a certain type of event detector which was being built to search for evidence for a particular candidate of dark matter.

Chinglu never understood what most readers understood --
• that the existence of WIMPs and LSPs were hypotheses and
• that the existence of some sort of massive particle making up the bulk of cold dark matter was empirical fact.
The detector described in the opeing post should find WIMPs if they exist, because we can accurately model WIMPs and very massive analogues of neutrinos. Chinglu makes up various assertions which were never tied to any model and demonstrates repeatedly the dishonest portrayal of himself as someone who knows something about electroweak interaction or stability of electrons.

Contrary to Chinglu's present assertions, no one has claimed to know anything about dark matter other than
• the cosmological fit established its average mass density in the universe,
• local astronomical estimates establish its density in our galaxy and others, and
• a crude lower bound on the per-particle mass of 250 GeV.
A heuristic upper bound on its mass was given based on the low cross-section with matter while we tried to puzzle out what gave rise to Chinglu's claim about how a massive particle implied that electrons would be unstable and the stability of the hydrogen atom was used as a surrogate for a claim that was never tied to any physical model. The hypothesis that dark matter interacts via the weak force was not falsified by Chinglu's ignorance of the weak interaction and neutrinos. That Chinglu confuses neutrons and neutrinos is strong evidence that he knows nothing about R-duality and this is just a phrase that was copied off a Wikipedia page without understanding.

In the above post, Chinglu spits in the face of
• people who know things about dark matter,
• people who know things about the weak interaction,
• people who built the detector (who presumably knew both of the above and yet were perfectly clear that WIMPs are only dark matter hypothetical candidates),
• moderators who were patient enough to explain why Chinglu's claims made no sense, and
• people who know that quote-mining and argumentum ad font don't belong to science.
.

Ideally, moderator will not condemn posts 1-5 to whatever repository of anti-science Chinglu's claims belong to.

// BTW -- $\frac{\Omega_{\tiny c}}{\Omega_{\tiny m}} = \frac{\Omega_{\tiny c} \, h^2}{\Omega_{\tiny m} \, h^2} \approx \frac{0.1122}{0.1347} \approx 83%$ from table 1 of http://lambda.gsfc.nasa.gov/product/map/dr4/pub_papers/sevenyear/cosmology/wmap_7yr_cosmology.pdf but that number is the result of a specific understanding that Chinglu doesn't possess and therefore cannot articulate.

12. ### AlphaNumericFully ionizedRegistered Senior Member

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6,697
That's a misrepresentation. I never said I knew. I was responding to a claim you made that dark matter necessarily leads to an unstable electron. The MSSM is a particle physics model which makes predictions we can test (the LHC is searching for supersymmetry!), has particles in the range 100GeV to 1000GeV, which is about 100-1000 times the proton mass you mentioned, and which has a stable electron. Therefore your assertion the electron necessarily becomes unstable in such circumstances is demonstrably false.

None of that has anything to do with whether I think the MSSM is true or not or whether dark matter exists or not or what Harvard says or not. It was a response to one of the many unjustified blanket assertions you made. An assertion you have failed to back up, despite being asked several times and despite demanding other people back up their claims. You cannot go around demanding people answer your questions and provide you with X, Y and Z and then refuse to respond to questions you are asked or refuse to back up your own assertions. Worse, when such things are provided you ignore them.

It's bad enough to make blanket assertions which demonstrate you don't even know there's a difference between dark matter and dark energy, despite being told several times by more than one person, but this behaviour of yours is unacceptable.

Anyone who actually bothers to read this thread properly, which you haven't done, will see I never said anything of the sort.

You've done enough misrepresentations for the time being. Enjoy your holiday.