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Biggest dark matter detector spots a single weird particle

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Re: Biggest dark matter detector spots a single weird particle

#51

Post by hyperhello »

gizmo686 wrote: post #46
hyperhello wrote: post #40

Earlier quoted context omitted.

It's possible that there could be an entirely different charge mechanism that works exactly like ours but they don't interact at all; but the whole premise of dark matter is that it doesn't seem to have any self-interaction outside of gravity.

The premise of dark matter is that it is something with gravity that does not otherwise interact with any of our detectors (e.g. "normal" matter); or that any such interactions are weak enough that it is plausible we have not noticed. By itself, that does not exclude the possibility of dark matter having other interactions which do not interfere with our detectors.

I guess so. If you could sort of measure the dark matter distribution, there might be a structure under it, but strictly speaking isn’t it limited to saying it’s not at least likely to emit light but does have mass.

Re: Biggest dark matter detector spots a single weird particle

#52

Post by gus_massa »

dd8601fn wrote: post #50
WarmWash wrote: post #37

Earlier quoted context omitted.

Reminds me of the FTL neutrinos too, where the scientist where pretty much "hey, something is wrong, can you help us figure it out?" and the general public were the ones screaming "OMG! Physics is dead!" Then when it comes out as measurement error, the public is all "Damn these scientists are all hype machine clowns..."

I’m fine with that. Put it at the feet of pop science blogging. I’m less fine with the time and resources spent on mouse models. They already know you’d get the same utility from a magic 8 ball, but they do it anyway.

Mouse models are useful to discard very bad ideas. There was a recent experiment to use bacteria to kill cancer https://news.ycombinator.com/item?id=46306894 They tried like 40 bacterias in vitro, then like 9 in mice, and only 1 was useful in mice and they will continue only with that, perhaps in humans. Anyway, as you suggest, there is a high chance it will fail.

Also, you can do nasty stuff to mice that would never be allowed with humans. In that experiment they injected cancer cells in mice with a bad inmune system, so they could get like 90 mice with cancer and run the experiment in a short time. No ethical committee would approve that in humans.

Re: Biggest dark matter detector spots a single weird particle

#53

Post by cogman10 »

cwmma wrote: post #48
cogman10 wrote: post #44

Earlier quoted context omitted.

Makes me wonder if all atoms with 2+ nucleus elements (protons and neutrons) are radioactive but the halflife is so far out as to make something we'll never detect.

Probably not, they have a pretty good handle on why atoms decay, to the point they can predict some to be radioactive before it's actually observed to be (like Bismuth-209). Also even if something is REALLY REALLY long lasting, you can still check for the halflife by observing enough of it, they've been able to rule out proton halflives under 10^34 years (the universe is on the order of 10^10 years old) but by observ…

> they have a pretty good handle on why atoms decay

Oh, they actually don't. Radioactive decay, AFAIK, is still an open physics mystery. We know it happens, we don't know why, what causes it, or if there even is a cause. We can predict factors that make it more likely.

> to the point they can predict some to be radioactive before it's actually observed to be (like Bismuth-209).

Right, but Xenon 124 wasn't predicted to be radioactive which is what makes it fascinating. It shows holes in what we can predict as being radioactive which is what makes me wonder about everything being radioactive but the timetable is too far out.

Re: Biggest dark matter detector spots a single weird particle

#54

Post by pfdietz »

WarmWash wrote: post #37
smueller1234 wrote: post #10

Earlier quoted context omitted.

Or this[2] 2007 Science paper on ultra high energy cosmic ray source candidates ("anisotropy") that we had to retract because significance started dropping almost the day the paper was approved. It was a fascinating experience as a junior member to follow the collaboration internal conversation and investigation on this, because a lot of extremely principled scientists were clearly deeply worried about losing their h…

Reminds me of the FTL neutrinos too, where the scientist where pretty much "hey, something is wrong, can you help us figure it out?" and the general public were the ones screaming "OMG! Physics is dead!" Then when it comes out as measurement error, the public is all "Damn these scientists are all hype machine clowns..."

That was a fiendish thing to debug; if I recall correctly it was a slightly and intermittently defective connector.

Re: Biggest dark matter detector spots a single weird particle

#55

Post by tomrod »

ajkjk wrote: post #23
irishcoffee wrote: post #22

Earlier quoted context omitted.

You have accurately described a email mailing list. Where in the value-add here?

You think that people's findings should be communicated by email? that their email chains are what should go into the permanent record and be cited and printed out and included in journals and such? would you include all the quoted text in the reply-alls, or is that too much?

That's how Linux is built.

Science has too many threads to do it successfully though

Re: Biggest dark matter detector spots a single weird particle

#56

Post by pfdietz »

gus_massa wrote: post #16
SaberTail wrote: post #9

Earlier quoted context omitted.

To start with, they do a lot of work to eliminate radioactive backgrounds in the materials they're using, and they put the detector deep underground to shield from cosmic rays. Additionally, when a particle interacts with the nucleus, the ratio of how much energy ends up as scintillation light versus ionization is different than when a particle interacts with an electron, which is most of the background processes. Th…

I agree. Moreover, I'm not sure if it's the same team, but in a similar experiment while removing all the other effects, they discovered that Xenon 124 is radioactive, but the half life is super long and no one had seen it before. https://xenonexperiment.org/observing-the-rarest-decay-proce...

Those double beta decays are also interesting because they can probe whether the neutrino is a Majorana particle.

Re: Biggest dark matter detector spots a single weird particle

#57

Post by EthanHeilman »

irishcoffee wrote: post #22
matthewdgreen wrote: post #21

Earlier quoted context omitted.

This sort of thing is really useful for helping people to understand what the purpose of scientific publication is. It's not about presenting finished products to society, it's more like a Discord where you communicate new findings with other authors. Often the reason for a communication is because you found something weird, and you want other people to know about it so they can help you confirm or rule it out as bad…

You have accurately described a email mailing list. Where in the value-add here?

> You have accurately described a email mailing list. Where in the value-add here?

Pre-prints are basically a mailinglist where you post your paper prior to peer review.

The value over a simple mailinglist is:

1. Stable URL and citation to enable other work and discussions to cite and reference it.

2. Versioning of the paper, allowing updates to be made without having mail out the paper, while allowing everyone to find all prior versions

3. Host for a PDF and data that might be quite large

4. Centralized searchable long term archive of scientific papers

5. Scalability, arxiv gets 30,000 submissions a day, no one wants to receive 30,000 PDFs in their inbox everyday

Re: Biggest dark matter detector spots a single weird particle

#58

Post by logdahl »

smueller1234 wrote: post #10
SaberTail wrote: post #5

I read their preprint[1] and they did a thorough job. They investigated a number of the things I'd suspect if I were looking for mis-reconstructed events or weird backgrounds. So it's certainly interesting! That said, particle physics history is full of 3 sigma particle "discoveries" that disappeared with more data. They're collecting more, so hopefully we'll learn more in a few more years. [1] https://lz.lbl.gov/wp-…

Or this[2] 2007 Science paper on ultra high energy cosmic ray source candidates ("anisotropy") that we had to retract because significance started dropping almost the day the paper was approved. It was a fascinating experience as a junior member to follow the collaboration internal conversation and investigation on this, because a lot of extremely principled scientists were clearly deeply worried about losing their h…

Wow haha, that is a lot of authors! Never seen this before!

Re: Biggest dark matter detector spots a single weird particle

#59

Post by kstrauser »

isomorphic wrote: post #42
advisedwang wrote: post #31

> Such behavior could require dark matter to be more complicated than just a single new type of particle. For example, the dark matter particle might have some internal structure, like an ordinary atom, so it would only interact if hit hard enough to excite it to a higher energy internal state I get a little shiver imagining that the dark matter might be something like ordinary atoms. Imagine that other 85% of the un…

I've heard this referred to as a "dark sector", or "hidden sector": https://en.wikipedia.org/wiki/Hidden_sector The scary thought is that, were it true that there is voluminous richly-interacting dark matter, we would be the actual dark sector.

"Imagine a universe, like ours, overlapping ours, except where some of its matter spontaneously rips itself apart, and other matter can be mashed together if you squeeze it hard enough." "That's nightmare fuel! Fortunately it's probably impossible, so far as we can tell."

I can imagine other scary thoughts, though. Ever read any Warhammer lore?

Re: Biggest dark matter detector spots a single weird particle

#60

Post by XorNot »

matthewdgreen wrote: post #43
irishcoffee wrote: post #22

Earlier quoted context omitted.

You have accurately described a email mailing list. Where in the value-add here?

If I had the email address of every researcher in my field, I would never send a mass email to them describing my latest goofy idea. I would, however, send my latest goofy idea to a conference with those same reviewers (if I felt it was technically appropriate and correct.)

I mean we use to have newsgroups which basically implemented this.

Which of course is the point: it is in fact quite similar to a mailing list, just with some extra protocol surounding it to make it manageable.

So the attempted snark about it up thread is stupid.

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