Questions regarding dark matter dynamics

[Adrian59]

Apologies, the first sentence of my entry in no. 61 is an error that was part of no. 60.

 

[Drakkith]

This is a good point though some, Stacy McGaugh for example, question whether this is actually what is happening since early experiments have failed to find exotic dark matter particles the goal posts are moving. The graph of cross section versus mass of possible WIMPs is constantly being redrawn as experiments fail to find the WIMP at a particular energy. So with each failure the line is redrawn to a new mass / cross section and the hunt continues.

That seems to be exactly what you should do if your experiments fail to detect something. If it takes an exhaustive search then it takes an exhaustive search.

 

[MichaelMo]

That seems to be exactly what you should do if your experiments fail to detect something. If it takes an exhaustive search then it takes an exhaustive search.

It's also possible to make an exhaustive search for something that does not exist. When is it time to call off the search? How much do we have to spend before we accept all the NULL results as evidence of non-existence?

 

[Drakkith]

It's also possible to make an exhaustive search for something that does not exist.

Absolutely.

When is it time to call off the search? How much do we have to spend before we accept all the NULL results as evidence of non-existence?

I can't answer that. That depends on things like how difficult it should be to detect the particles, cost of the experiments, possible alternatives, etc.

 

[MichaelMo]

I can't answer that. That depends on things like how difficult it should be to detect the particles, cost of the experiments, possible alternatives, etc.

When I was a kid I heard the term "the grunion are running" from one my friends. I was really "skeptical" when I heard about grunions on the beach from my friend because I'd been to the beach many times at night and I'd never seen a grunion, and in fact I'd never even heard of them before and we lived pretty close to the beach. My mother explained to me that grunion were real and to demonstrate that they were real, she woke me up one night to take me to the beach to watch them come up on shore during a full moon to mate and go back to the ocean. I was amazed and excited because I'd never seen that before.

Unfortunately a few months later I fell prey to a "snipe hunt" adventure when I mentioned grunion to a couple of my older friends. They assured me that snipes were like grunion and I just needed to look for them at the right time, and the right place(s), I spent a long time searching for snipes one night at their urging. I looked and looked and looked everywhere they suggested. The kept telling me that they could "hear" them too, so they knew they were around here somewhere. I finally started to get suspicious when they kept changing their stories about what snipes looked like. Their stories kept changing over time and they got more and more elaborate in terms of why they were hard to find. That is what finally convinced me that snipes were not real and I wasn't ever likely to find them, so I finally stopped looking.

Dark matter has the same feel about it as my snipe hunt. There are conflicting hypotheses about the composition of DM, and the searches to date have been about as productive as my snipe hunt although vastly more expensive of course. I can't shake that "snipe hunt" feeling anymore, particularly after LHC and the last LUX and Xenon1T results.

 

[Drakkith]

Dark matter has the same feel about it as my snipe hunt.

Look, you've repeatedly made it clear that you are highly skeptical about dark matter existing and you've given your reasons. That's fine. But there's no reason to continue to protest. Figuring out the laws of the cosmos is inherently very difficult and cosmologists have good reasons to include dark matter in the current standard model of cosmology, something that's most likely not going to change anytime soon (though it's always possible that new evidence will crop up tomorrow). You are certainly free to disagree with them, but keep in mind that there's really no reason for anyone to trust your opinion (or anyone elses) over the consensus of the mainstream community.

This thread has been off-topic since page 1 so I think it's time to close it.

Thread locked.