Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

RIP Higgs Boson (with 95% confidence)

blogs.scientificamerican.com

Post reply on HN
Print view View original

111–120 of 153 posts

Re: RIP Higgs Boson (with 95% confidence)

#111

Post by tzs »

Tichy wrote: post #109
tzs wrote: post #33

Earlier quoted context omitted.

> Europe explored the universe where America did not I guess you never heard of a little project called the International Space Station? The SSC was supposed to be a $4 billion project. That's what Congress was told in 1987. By 1993, it was projected as a $12 billion project. Guess where that $8 billion would have come from if the SSC project had continued? From other science projects--and most likely the ISS would h…

I am not a specialist on that matter, but I suspect it is called "International Space Station" rather than "American Space Station" for a reason.

Over half the funding comes from the United States.

Re: RIP Higgs Boson (with 95% confidence)

#112

Post by [deleted] »

guygurari wrote: post #110
sskates wrote: post #108

Earlier quoted context omitted.

Maybe I'm missing something, but how is this argument flawed? Bayesian probability says that eliminating possible universes increases the probability of other ones (given everything else as constant). So reducing the probability that the Higgs Boson lies in some energy range (which is what this experiment did) increases the probability that a) the Higgs Boson doesn't exist and b) the Higgs Boson exists at some other…

I think we should be careful with Bayesian inference for the usual reason -- there is only one universe with one (or zero) Higgs particle. You can't really collect statistics over universes, so what is the meaning of probability in this case? More concretely, what prior probability would you assign to the distribution of the Higgs mass? This depends on your theory. For instance, supersymmetric theories tend to favor…

[deleted]

Re: RIP Higgs Boson (with 95% confidence)

#113

Post by gjm11 »

archgoon wrote: post #104
Eliezer wrote: post #88

It's too early to call this one for sure, but still, I'm proudly on the record as betting against the Higgs. http://wiki.lesswrong.com/wiki/Bets_registry

You bet even odds. Does this mean you are equally likely to expect a Higgs as not, or simply that your belief of there being no Higgs is equal to that of RolfAndreassen's belief that there is one? Genuinely curious here.

The odds (and size of bet) were proposed by the other party. So all you can deduce is that Eliezer thinks Pr(Higgs)<1/2. (If you have a good estimate of Eliezer's risk aversion level for bets of that size, you might be able to get a slightly better estimate, but my guess is that it's extremely close to zero.)

Re: RIP Higgs Boson (with 95% confidence)

#114

Post by danmaz74 »

guygurari wrote: post #110
sskates wrote: post #108

Earlier quoted context omitted.

Maybe I'm missing something, but how is this argument flawed? Bayesian probability says that eliminating possible universes increases the probability of other ones (given everything else as constant). So reducing the probability that the Higgs Boson lies in some energy range (which is what this experiment did) increases the probability that a) the Higgs Boson doesn't exist and b) the Higgs Boson exists at some other…

I think we should be careful with Bayesian inference for the usual reason -- there is only one universe with one (or zero) Higgs particle. You can't really collect statistics over universes, so what is the meaning of probability in this case? More concretely, what prior probability would you assign to the distribution of the Higgs mass? This depends on your theory. For instance, supersymmetric theories tend to favor…

Bayesian inference is applicable here, because we are talking about the subjective probability - ie, confidence - that one single fact is true. There is no way to reduce a single "event" (that there is Higgs particle or there isn't) to a frequentist, or "objective", probability.

As you correctly say, the influence that the results we already got about the possibility that Higgs boson exists with a high mass have on the global possibility that there is a Higgs boson depend on the a-priori (to the current experiment) confidence that we give to the high mass/low mass hypotheses. So there is for sure not a 95% drop in confidence, but there is indeed a drop, unless you gave 0 confidence to the high-mass hypothesis before the experiment.

Re: RIP Higgs Boson (with 95% confidence)

#115

Post by eric-hu »

guygurari wrote: post #84

I'm a particle physics grad student. My god, what utter nonsense. The only reasonably accurate paragraph is this: "And, more importantly, the lower energy range from 114 to just under 145 billion electron volts, a region of energy that Fermilab has determined, through earlier experiments, may harbor the Higgs, has not been ruled out. But the Higgs is quickly running out of places to hide." The region of higher Higgs…

Didn't the author of the article shoot himself in the foot with this statement:

> These assessments carry a probability measure, such as 95%, 99%, or—as traditionally required in particle physics for a “definitive” conclusion about the existence of a new particle: 99.99997% (this is the infamous “five-sigma” requirement).

So...the five-sigma requirement means that your run-of-the-mill physicists won't accept a claim until there's statistical evidence accurate to 99.99997%. From 95% to ...that number is still a significant number of tests, no? Doesn't this paint the title as sensationalist with the author's own words?

Re: RIP Higgs Boson (with 95% confidence)

#116

Post by gjm11 »

evgen wrote: post #37
SoftwareMaven wrote: post #30

Earlier quoted context omitted.

Its gravitational effects have been observed, that is how we know it is there. Nobody has seen it, but little in the sky is actually accessible via visible wavelengths.

A gravitational anomaly has been observed, but the source of this anomaly is not just invisible to the visible wavelengths but from all wavelengths we can measure. "Dark matter" sounded a bit better than "unicorn turds" I guess, but at the moment each is equally likely.

> at the moment each is equally likely.

Impossible. Unicorn turds would be a variety of dark matter; if most of the apparent mass in the universe were made of unicorn turds, the dark matter hypothesis would be correct. (Unless they were very sparkly unicorn turds, emitting enough light for us to detect from far off.)

Further: they'd be a very boring kind of dark matter: the same kind of stuff as we, the earth, the moon, etc., are made of. And there's very good reason already to believe that there isn't enough of that to account for the gravitational anomalies you get if you assume no dark matter.

I therefore declare: Pr(anomaly comes from unicorn turds) is much smaller than Pr(anomaly comes from dark matter).

Re: RIP Higgs Boson (with 95% confidence)

#117

Post by fauigerzigerk »

guygurari wrote: post #84

I'm a particle physics grad student. My god, what utter nonsense. The only reasonably accurate paragraph is this: "And, more importantly, the lower energy range from 114 to just under 145 billion electron volts, a region of energy that Fermilab has determined, through earlier experiments, may harbor the Higgs, has not been ruled out. But the Higgs is quickly running out of places to hide." The region of higher Higgs…

I'm not sure I follow your first argument. The probability of finding the item in the remaining 5% of the search space is independent of the time required to search different sections of the search space (unless of course you have additional prior information about where the item is more likely to be located).

The fact that it may take you, say, 90% of the time to search a particular 10% section of a search space doesn't increase the probability of finding the item in that section.

Re: RIP Higgs Boson (with 95% confidence)

#118

Post by guygurari »

danmaz74 wrote: post #114
guygurari wrote: post #110

Earlier quoted context omitted.

I think we should be careful with Bayesian inference for the usual reason -- there is only one universe with one (or zero) Higgs particle. You can't really collect statistics over universes, so what is the meaning of probability in this case? More concretely, what prior probability would you assign to the distribution of the Higgs mass? This depends on your theory. For instance, supersymmetric theories tend to favor…

Bayesian inference is applicable here, because we are talking about the subjective probability - ie, confidence - that one single fact is true. There is no way to reduce a single "event" (that there is Higgs particle or there isn't) to a frequentist, or "objective", probability. As you correctly say, the influence that the results we already got about the possibility that Higgs boson exists with a high mass have on t…

I'm not saying Bayesian inference isn't applicable, I'm just cautioning against an careless interpretation of its results. But if you insist on interpreting it in this way then yes, it means the probability of finding a Higgs is lower.

However, as I said above the term "95% confidence" is not related to this reasoning at all. Saying for example "the Higgs mass is not 140 GeV at 95% CL" means precisely: If the Higgs were at 140 GeV, it would have 5% probability of producing the results we measured experimentally. It does not mean "we are 95% sure the Higgs isn't at 140 GeV".

Re: RIP Higgs Boson (with 95% confidence)

#119

Post by guygurari »

eric-hu wrote: post #115
guygurari wrote: post #84

I'm a particle physics grad student. My god, what utter nonsense. The only reasonably accurate paragraph is this: "And, more importantly, the lower energy range from 114 to just under 145 billion electron volts, a region of energy that Fermilab has determined, through earlier experiments, may harbor the Higgs, has not been ruled out. But the Higgs is quickly running out of places to hide." The region of higher Higgs…

Didn't the author of the article shoot himself in the foot with this statement: > These assessments carry a probability measure, such as 95%, 99%, or—as traditionally required in particle physics for a “definitive” conclusion about the existence of a new particle: 99.99997% (this is the infamous “five-sigma” requirement). So...the five-sigma requirement means that your run-of-the-mill physicists won't accept a claim…

For discovering an effect the standard is indeed 5-sigma. But here we are discussing excluding an effect, namely deciding that a suggested effect isn't there. For this the standard is lower.
Post reply on HN