Neutrino experiment reveals inconsistency in how matter and antimatter behave
quantamagazine.org
quantamagazine.org
> That result got the community excited — although most physicists were quick to point out that with such a small sample size, there was still a 10 percent chance that the difference was merely a random fluctuation. (By comparison, the 2012 Higgs boson discovery had less than a 1-in-1 million probability that the signal was due to chance.)
My impression is usually they have some set of possible theories that predict the exact result observed, then go on to do more experiments to distinguish between the predictions of those.
Really they should just drop the significance testing because it adds nothing and they don't seem any better at interpreting those tests than other fields. If I am wrong about all this and that aspect actually is crucial, then physics is in trouble...
There is a bit more to it than just pure sigma values; it is also a matter of how closely the data fits the model overall, a lack of competing hypotheses to explain said data, and to what degree other evidence exists to support the model. Of course, if the theory being confirmed is complementary to existing physics, that also helps a lot. Having said that, 3 sigma is about when people started to get excited about the Higgs, and 5 sigma was confirmation.
So, all of the confidence and confirmation regarding the Higg's boson better actually be coming from "how closely the data fits the model overall, a lack of competing hypotheses to explain said data, and to what degree other evidence exists to support the model".
As an example, I'd imagine detecting the Higgs boson at 1 eV energy levels is theoretically predicted to be even less likely than billions/trillions to one odds, therefore detector noise would be a more likely explanation for such results, despite the low p-value.
That's not true. You can see plots in the 2011 and 2012 papers that give these calculations as a function of mass. It's basically impossible to make a mass-independent calculation. (Not withstanding the fact that there's no Higgsless theory to do calculations for the background).
>As an example, I'd imagine detecting the Higg's [sic] boson at 1 eV energy levels is theoretically predicted to be even less likely than billions/trillions to one odds, therefore detector noise would be a more likely explanation for such results, despite the low p-value.
You're right, the p-value is much lower. Previous experiments have long since excluded such a low Higgs mass. Also, if the Higgs mass were so low, we probably wouldn't exist.
2) "That's not true. You can see plots in the 2011 and 2012 papers that give these calculations as a function of mass."
- Can you explain what you mean via figure 1 in this paper: https://arxiv.org/abs/1207.7235 ?
- I don't see the relevance of calculating p-values as a function of mass to my comment
3) "Not withstanding the fact that there's no Higgsless theory to do calculations for the background"
- Then what model did they use to calculate the p-values? (I do not know the details but am fairly certain it is one where there is no Higgs boson at any given mass)
4) "Also, if the Higgs mass were so low, we probably wouldn't exist."
- Ok, but I've also read headlines like "CERN proves the universe shouldn't exist", clearly this is just because their model of the universe is wrong. I'm sure in a pinch people could come up with some kind of balancing out of whatever problems would arise from such a small Higgs mass. The point was that assuming the current theory is correct, the Higgs would be a much worse explanation than detector noise.
RE 3: The model used to calculate the background are unphysical in the sense that they set the Higgs production cross section to zero without changing anything else. There's no physical Higgsless theory.
RE 4: I was agreeing with you and adding some facts.
Sorry, I still don't see what information is being used that requires theory/evidence regarding the Higgs boson. Whether or not anyone knows about the Higgs boson they could be plotting p-value by mass for these experiments.
>"The model used to calculate the background are unphysical in the sense that they set the Higgs production cross section to zero without changing anything else. There's no physical Higgsless theory."
So they actually change their model to be surely false, then go on to prove the known false model they just created... is false. This is pointless.
he was saying, the mass calculation depends on the theory about the higgs? they can't just put it on a scale :)
This makes the significance testing they do even more ridiculous though. At first I thought the model of background noise was simply not providing much info about the topic of interest: the existence and mass of the Higgs.
According to what I have learned here, it is much worse. Not only are they testing a purposefully rendered false model (and taking rejection of that known-false model as evidence for the Higgs), but they are also assuming the Higgs exists (and has whatever properties you all are referring to) as part of this process. As a result, the Higgs exists either way (whether background model is rejected or not) according to this process.
Doing this test sounds pretty meaningless to me.
Sine we are living in matter dominated region of space it would stand to reason that most stellar neutrinos that pass through us are matter neutrinos.
But I guess you are right. I just read that in case of some more energetic neutrinos interaction can create electron muon or tau dependant on neutrino flavor.
https://arxiv.org/abs/hep-ex/9807027v1 [1998]
The T2K experiment is in a way essentially another calibration system. It of course has its own overview page at http://t2k-experiment.org/t2k/
"It is essential that the direction of the neutrino beam be stable to within 1/20 th of a degree, and that the intensity of the beam be constant over time ..." http://t2k-experiment.org/t2k/
While turning it on and off or steering it differently seems like it would help generate correlations with the detectors to distinguish T2K daughter products from those of other phenomena, the total set of detections are fleetingly rare. Moreover, the background is reasonably well characterized from the more than ten years before T2K existed, peppered with data from the various periods when T2K's beam was off for extended periods.
A brief explanation of why the T2K's beam is angled slightly away from the SK detectors is elsewhere at the same link.
Then, "some experts" not "[all] experts" since supersymmetry is not universally accepted with its lack of evidence.
Not necessarily. The seesaw mechanism [1] itself does not require supersymmetry, it's quite generic.
Universe formation is how the universe "formed".
Universe existence is how the universe come to exist out of nothing.
The article and neutrino experiment talk about the former. The latter is more interesting, though.
So it’s interesting to think about, but there are reasons to believe that humans will always lack the tools to find the answers. Imo that makes it feel like questions about the existence of god, or an afterlife. They are important and have massive bearing on our existence, but I doubt in our ability to answer them, or even to ask the right questions in the first place. In that sense, they’re less interesting than questions we can actually formulate and hope to answer, like the “hows” rather than the “whys” of existence.
I feel like somehow, we are way off in our understanding of the universe and how it works. There are so many unanswered questions, such as:
1) If the big bang created space and time as we know it, what was there before that?
2) Why did the big bang suddenly occur 14 billion or so years ago? Why not a couple billion years before or after that?
I know that the steady state theory of the universe has fallen out of favor, but I wonder if some appeal could be made to some kind of fundamental force that has always existed and always will, which behaves with fluid dynamics, and the "islands" of matter that we experience are actually some kind of fluctuations in that fluid.
2) We should expect to find ourselves in a time and place that accommodates observers, see o https://en.wikipedia.org/wiki/Anthropic_principle
And the other big point is that our concept of time might be flawed. Maybe in relativistic terms, from our point of view it was a few seconds, but it actually took an eternity and you could keep observing closer and closer to the origin (in the diagrammatic sense) but never reach it, so who even cares, still? So, in a way more easily grasped by humans, it would be more apt to say, there is no after, because we will possibly never get behind it in our way forward. Does that seem sensible to you?
2) Because that's when the size of the universe in the calculation reaches plank scale? I'd like some correction because I have read before that plank scale is not actually a hard physical boundary, but I believe we just don't have the tools to say anything about that time with any certainty. And don't be mistaken, there are loads of competing theories and all have warts, paradoxes and open questions. Such is life, ironically, which I still think is a comfortable closure.
I have trouble accepting CP symmetry violations.
Universe does seem to exist, though, doesn't it?
How would you explain that without CP symmetry violation?
My preferred explanation is that areas dominated by matter and anti-matter got pushed away far apart by the energy of annihilation between them, universe is much larger than observable universe and our galaxy, neighbouring galaxies, possibly even whole observable universe belongs to region that was dominated by matter that is now separated from anti-matter dominated ones with sufficiently large and empty void.
I don't exactly buy the idea that all of the matter was at the beginning in one geometrical point, and exactly uniform. Background radiation is not exactly uniform so imho not all places in space had exactly the same amounts of matter and anti-matter either.
Physicists in the audience, is that an accurate assessment or should I go back to excitedly clicking through when I see them?
Just my gut though, as a dilettante.
QuantaMagazine is a very good bridge between cutting edge research and layman. What does leak even mean? They don't write titles to be "hackernewsed".
This headline in question is also totally normal, not sure why you have a problem with it.
Can you come up with a more grandiose title?
Edit: okay, it's in the first paragraph, but still. Scientists are trying to detect new particles or particle interactions. Nothing new about that, superficially speaking. but it doesn't explain all of the big bang, maybe a piece of the puzzle, but not at all why it happened.
Another offense to scientific writing is the antropomorphism. It's actually the scientists who actively suggest the story and they surely wouldn't go for quite as bold a statement.
In terms of storytelling we can assume that there's a lot of importance in what isn't said, and that's often achieved by exaggeration of known wrongs, as in sarcasm. Nothing particularly wrong about that, but not terribly scientific. Take away the whole fluff and you have a report about an experimental result with low p-value and the plan to improve it via added reaction mass which is not further explained. That's hardly the mystery, it's a key to the puzzle, maybe.
Edit: to elaborate further on the weaselisms. Solutio to mystery kinda annihilates, just like antiparticles and counterparts, so the headline corrected for all would be: Scientists suggest Neutrinos prove Universes Existence. Welp, color me slightly unimpressed. Though I'm complaining on a high level, this is actually super cool just not new to me.
It's interesting you've invented your own quantum chromodynamics of English but, really, that's a perfectly normal, pedestrian (stable, if you prefer) and widely used phrase with a clear, unambiguous meaning.
Regarding other subjects, I'm no expert, but I appreciate their style (and I have to say their infographics are very pleasing on the eye). I never watch videos or multimedia content so I can't vouch for the videos either (which others in this thread have expressed appreciation for).
In this case, this is something that might explain a CP violation that can explain why we exist in a universe of matter. To a physicist, explaining it is a CP violation is grandiose enough. But in reality the title is not at all misleading as CP parity is one of the biggest unsolved problems in physics, and yes it is a mystery as to why we have a universe of matter that exists. So while it may seem ambitious to a person in the field, it is indeed truthful and exciting research.
And that is just the ideal case, where journalists report on experiments. In theory most articles are just as interesting as someone created a branch on a github project, that is the very first step towards something that may develop into something interesting, or it may not.
So yeah, "just getting anyone to speculate what a finding means is hard," because everybody knows that science journalists try to feed the public bullshit. Seriously, every single climate change denier I ever discussed with has given me page after page of links to popular science reporting where the entire problem was, that the journalist found someone who was willing to speculate and these speculations turned out to be wrong.
I find this to be a repeated pattern where some fault is immediately assumed by the submission without any explanations to support their case as to why HN audience should mistrust it.
> Physicists in the audience, is that an accurate assessment or should I go back to excitedly clicking through when I see them?
It doesn't instill much confidence to call something shit and then forcing the onus on somebody else with more expertise to support their jaundiced claim without any supporting arguments.
At least if you are going to call something as untrustworthy, back it up with examples and clear explanations as to why we should not trust it.
It's true that the significance isn't enough to meet the standard in particle physics, but a result will always be weak before it is strong, so this is still something that's exciting. It should also be noted that the 5-sigma "standard" is set to be so stringent partially because physicists in the past were not so good at estimating things like trial factors and systematic errors. We are better at this now (and T2K has some talented statistics-minded physicists on it), so I wouldn't immediately dismiss it on those grounds.