Live CERN Higgs Announcement in 20 Mins
webcast.web.cern.ch
webcast.web.cern.ch
IANAPhysicist, but I'd be interested to know how strict the 5-sigma discovery rule is considered - for example, could they still get a Nobel prize for a 4.9σ announcement? I suppose it's not that big a deal - the LHC is still running, and I'm sure they'll have enough data for a true 5σ announcement soon. Regardless, hats off to all involved, it must be exciting to be at the forefront of human knowledge :)
Edit: It is worth noting that 125GeV fits well within Fermilab's recent announcement: http://news.discovery.com/space/tevatron-data-detects-higgs-...
In all seriousness, does anyone know how common it is to do this kind of gradual reveal during scientific presentations vs. stating your basic final results in the introduction? It's kind of fun, but you could cut the tension in that room with a knife!
http://press.web.cern.ch/press/PressReleases/Releases2012/PR...
It's very much a HEP thing, and done that way because HEP is pretty much all statistical analysis these days. Other fields wouldn't treat the sigmas as the most important thing, and I've heard mutterings that it's not really the most accurate approach - but it is objective and easy to apply.
I'm kind of joking - most other scientists don't collect enough data to have to worry about 1 in 10,000 events happening by chance. In medicine, though, I'm not joking at all - those guys publish absolute statistical garbage all the time, I hesitate to even consider it a science because the data dredging is so bad. I can "prove" just about anything if the publication standard is 95% significance...
Also more generally known as the "multiple testing" problem, fwiw (not sure why it has a different name in physics, unless I'm missing a subtlety).
It's a major problem in "big data" also, where people just data-dredge thousands of possible parameter choices and pairwise correlations, and then report the p<0.01 results that came up, even though you'd expect several false positives just by chance with that methodology.
By the way, σ measurements are also used in many engineering jobs, and quality systems measurements. The kind of industry "goal" is to get 6σ (let's say when you manufacture consumer goods in large quantities, like millions every month). But for some other industries, 9σ is the benchmark - and from what I know, air companies have quality systems up to 9σ to ensure the lowest risk of something wrong happening.
6 Sigma is 3.4 defects per million opportunities. http://en.wikipedia.org/wiki/Six_Sigma
No!! It's the chance that randomness could produce a result that large. This distinction sounds pedantic, but misunderstanding this is widespread and leads to fallacies committed frequently by very smart people who ought to know better in many fields.
Consider, by analogy, the event "rolling a six sided die and getting a 6 and announcing that fact to the world".
"What is the probability that random events could produce a result that large?": one in six, per die roll. The question excludes the whole "announce it to the world" filter.
"What is the probability that these results [getting a six and announcing it] occurred by chance, rather than being a signal?": We have no idea. If the person announced "I'm going to roll one die and announce the results, regardless of the outcome", then it's one in six. If they kept rolling dice until they got a six, then the probability is 1. If they rolled 3 dice, then the probability is 91/216.
The point is that the scientific method has all sorts of biases (publication bias, confirmation bias, etc.) and p-values are rarely "probability that the result is wrong".
P(results | random noise is active)
You're talking about
P(the thing we care about | results)
The former is more like a simple sanity check. If random noise could have produced what you see, you shouldn't take the results too seriously.
The former tells you a little bit about the latter -- which is good, because the latter is what we actually care about. But you can't explicitly compute the latter without making much stronger assumptions like priors and the like. That's why this last step of reasoning is often performed qualitatively.
A good stats book to read about all this is Larry Wasserman's http://www.stat.cmu.edu/~larry/all-of-statistics/
Of the 100 real drugs, you detect all of them. Of the 900 fake drugs, 5% of them falsely appear to work. So you have 145 drugs you think work, only two thirds of which actually work. The chance of any individual drug having obtained its positive results by chance is 31%, not 5%.
I have a guide to this here, since it's so common:
http://www.refsmmat.com/statistics/#an-introduction-to-data-...
(Side note: the average medical trial would only detect 50 of the working drugs, not all 100, so the real situation is even worse.)
And that's different from the chance that randomness could have produced the effect? How?
By analogy in the medical case, p = 0.05. The incorrect interpretation is that this means only 5% of drugs with statistically significant benefits actually achieved these benefits through luck; rather, the right interpretation is that 5% of the nonfunctional drugs somehow appeared to work.
You could also imagine testing 200,000,000 hypotheses which were all completely false. Even if you used CERN's level of statistical significance, you'd still quite likely find one hypothesis which appears to be true, simply by chance. The chance of that hypothesis being false is 100%, despite the significance level of 1 in 1,740,000.
So yes, 31% is exactly the chance that randomness produced the effect in the trial. But people will try to tell you that it's actually 5%, and they're wrong.
But you're saying that in your example both are 31%. So again, I ask, are we talking about two separate things? And if so, can you give an example where the two things have different values?
For CERN, the chance that randomness could produce this result is 1 in 1.74 million; the chance that the results occurred by chance is larger, but not computable with the information we have,
The guide I linked to above gives a much better explanation than this. I rushed my first post here, and I think I was unclear.
> "The chance that randomness could produce [the result]" was only 5%.
> 31% is exactly the chance that randomness produced the effect in the trial.
Imagine flipping a perfectly fair coin 100 times. You'd expect to see 50 heads, but you don't always -- it's just an average. Suppose you see 75 heads. What is the chance that you'd see 75 heads with a fair coin? Very very small. The chance that randomness could produce such a result is small.
Now, imagine you test 100 perfectly fair coins. A few of them give more than 75 heads, just by luck. You conclude they're unfair, since the result is unlikely otherwise. The chance that randomness produced the effects you saw is actually 100%, because all the coins are fair.
There's a difference between the question "How likely is this outcome to happen if the coin is fair?" and "Given that this outcome happened, how likely is it that the coin is fair?" Statistical significance addresses the first question, not the second.
1. I'm rolling two dice to try and get the highest total. I get two sixes. What is the chance randomness produces this? 1/36, about 0.027. This more than a two sigma result. What is the chance that this is caused by random chance? 2.7%? Nope, 100%.
2. I study the same thing in a million situations in parallel. I take the most extreme result and find that random chance can produce this one time in 1.7 million. It's a five sigma result! What are the chances this result is caused by random chance?
The second presentation showed a 5 sigma result.
I'm Incredibly disappointed by the trivial inaccuracy of comments on hacker news lately, and that corrections never get upvoted quickly enough to prevent the spread of misinformation.
"I know a lot of people are tuning in without degree's in Physic's. Let me break it down for you in Leymens terms. We are fairly certain we have discovered this. It is important because of that. Now let me get onto why we think this."
I get that this talk is not meant for me. However, it is important - apparently. Its on the front page of Guardian.
If this is an announcement of great importance and it is 98% mumbo jumbo aimed at high end Physicists or whatever then.. I don't know. Its another chance to get people interested in science that has been missed.
Note: I am not saying the whole talk should be dumbed down. I am just saying a 2-3 minute prefix for those who do not understand a single word for the first 20 minutes of the presentation.
NASA handles these kinds of announcements well, but then they also announce cyanide-based life. So.
Its like NASA landing on the moon without video and presenting geology findings based on the rocks. Sod that. The people want to see VIDEO! They want to live the moment. I thought this could be one of those moments where something significant was discovered which I may be asked about in many years time. A "this changes everything moment." The way it is presented though may be just that for scientists. For everyone else though.. who cares when the announcement is this technical.
Surely I wasn't the only person wondering if we are not closer to the hover board? That would have been a nice way to start.
Screenshot of hoverboard "For the leymens tuning in. Our discovery means this is / is not closer to being made."
Ah ok, you're trolling.
PS - it's "laymen", not "leymens".
What I can tell you is, the parts which sound the most intimidating are actually probably the simplest bits. CERN operates a particle accelerator -- this means that the LHC basically smacks subatomic particles into each other at absurdly high speeds to create infinitesimal explosions with tremendous amounts of energy (these are the TeV, GeV numbers that you see -- they're talking about the amount of energy that was concentrated in the explosion). The explosion essentially disrupts the underlying fields of the universe so much that new particles can be created or destroyed, but if you excite the Higgs field to its quantizing particle, it tends to immediately decay into other things.
The other things are subatomic particles, including quarks (the letters u, d, c, s, t, and b for up, down, charm, strange, top and bottom -- you may have heard him for example say 'bb') and bosons (he talked a bit about W W* and gamma-gamma; gamma rays are light while W bosons are, well, a little more complicated let's say).
All of the stuff he says about Monte Carlo and so on is about creating "expected" curves from the Standard Model. You want to have two curves, "expected" vs. "actual", so that you can compare them.
On the base axis usually there is energy -- this is the energy of the explosion. There are usually two curves from Monte Carlo which tell you what you expect to see. Then there are data points with error bars which tell you what's actually seen and what the statistical "counting" errors are, how weak the signal is. Usually there is then a follow-up graph where they have tried to "subtract out the noise" to see the signal more clearly.
"We are 99.999995% sure we found it!"
Even if you are working at CERN running the equipment, there's no way you could absorb all the info on each of those slides in the 10 to 15 seconds she shows them. They might as well have pictures of frolicking kittens on them.
Also, focus on the content - if you're caring so much about the presentation, then you probably don't understand enough of the physics to comment on the content.
The worst powerpoint presentations are ones that are content-free - this one could be accused of too much content.
The properties of subatomic particles include something called 'spin' - that's a fundamental quantum mechanical property. The higgs boson is the first elementary (i.e. not made of other particles) spin-less particle that we've discovered; it's completely unlike anything that we've seen up until now.
That the model that we have constructed can accurately predict its existence and the way that it decays without having observed anything like that beforehand is a huge confirmation that we're in the right region of model space. Today seems to be a huge confirmation that out understanding of physics is not fundamentally broken.
That's why its important; the prediction is like attempting a 5-point dive and nailing it pretty much perfectly. It's an impressive confirmation of 50 years of theoretical work.
(The anarchist in me would have preferred them not to find anything, I must admit. That would have been much more interesting, as the standard model came tumbling down... :-)
What is the significance of discovering a particle without a spin?
Does this answer some questions about black matter, anti matter, big bang etc.
Then it would be interesting thing for us, laymen.
So - this is not about other questions in the first place, it's about the validity of the standard model. We can continue from there. (A common title for talks etc is "Physics beyond the Standard Model".)
I'm asking because I've seen a few casual descriptions of this Higgs as a "lightweight." I'm assuming that means it's not as heavy as expected?
EDIT: "If the mass of the Higgs boson is between 115 and 180 GeV, then the Standard Model can be valid at energy scales all the way up to the Planck scale (1016 TeV)."
http://www.daviddarling.info/encyclopedia/H/Higgs_boson.html
Atlas comes in at ~126.5 GeV with 5.0σ. That would be a confirmed discovery!
Interesting that Atlas' mass is outside CMS's confidence range, though Atlas didn't have a range on theirs.
Clarification:
http://public.web.cern.ch/public/en/lhc/LHCExperiments-en.ht...
"In this Letter, we report on the combination of Higgs boson searches carried out in proton-proton collisions at Sqrt[s] = 7 TeV using the Compact Muon Solenoid (CMS) detector at the LHC. ... Combined results are reported from searches for the SM Higgs boson in proton-proton collisions at Sqrt[s] = 7TeV in five Higgs boson decay modes: gg, bb, tt, WW, and ZZ."
They are talking about the standard model Higgs, which is the result of a specific way to break electroweak symmetry. A consequence is, that there are quite well understood predictions from this how the cross sections and branching ratios should look like. And on the current level of statistical significance it looks like a standard model Higgs.
On the other hand, there are so called effective field theories, that is you can start from a complicated theory and derive a simpler theory from it, which behaves the same in some aspects (for example at low energies).
So the more exact answer is probably that now a theory has to contain a Higgs boson in the appropriate limit.
Since the funding dried up for the Tevatron and the first hints for the discovery of the Higgs boson come from LHC we can conclude that Hawking won the bet and Kane will be the one paying up.
Since this is apparently "only seen" through the Monte Carlo analysis I suppose they haven't seen one specific particle decay with it, I suppose?!
(edit: The current ATLAS talk, not the first one on the CMS data)
However, as everyone else has said, it would have been lovely to have a layman's TL;DR. Perhaps that's the press conference at 11:00, and expecting it beforehand is arrogant.
www.studiostudio.nl/project-dyslexie/
So it's not unknown in advanced CS either :).
http://www.youtube.com/watch?v=0Vif4D-TJYQ
They must really like that font :)
It might be very interesting to try to use comet-casting or websockets to revolutionize chat in precisely that way, realtime threaded discussions. So, in addition to all of the chat constraints you have the ability to dynamically mark certain chat messages as replying to other messages, and as the noise in the chat room gets higher you can filter yourself to just "I want to follow this discussion."
in fact, many of my Waves were transferred to it
Isn't it open source now? I might try the open source version one of these days... Maybe I can even convince my friends to use it :).
For example, in CS we use a whole bunch of words like "string", "thread", "class", "type", "object", "arrow", "map" and "macro" to denote CS-specific concepts related at best tangentially to the words' original meanings. On the other hand, biology seems to prefer to come up with new words for their technical terminology.
I wonder if this is a product of different cultures or something like that.
Nuts are worse. According botanists, peanuts, cashews, macadamias, pistachios, walnuts, almonds, pecans, pine-nuts and Brazil nuts are not nuts. According to most lay-people, though, botanists are nuts.
They are.
Computer science people work in other areas, such as setting up and running the data collection and on-line processing. (A professor told us many interesting stories about the many Unix servers they build and the bugs they created..)
my understanding is that the computer engineers at CERN are mostly tasked with IT work, the rest (including DAQ software/firmware, network code, distributed+realtime data processing, etc) is made by the physicists.
Two of the really great text books in the field are by physicists,
1) 'Information Theory, Inference and Learning Algorithms' by David Mackay, a physics professor at Cambridge. Perhaps the most readable and enjoyable text book I own. Certainly up there.
2) 'Pattern Recognition and Machine Learning' by Chris Bishop, now a director at Microsoft Research in Cambridge but formerly a physicist. Delightfully, under the circumstances, his PhD supervisor was Higgs (yes, the one of boson fame)!
Can people please stop posting intervals in headlines i.e. "20 minutes!"
It expired a long time ago and was probably too late by the time the first people read it.
Please use at 12:00 UTC or something (a time).
Didn't he practice this before? Can't he just tell us what he wants to tell us, and skip over the rest?
He could have practiced this 6 months ago.
Aaaand... at this very second he's starting on the new stuff, I think.
I'm not exactly sure how you'd expect some sort of tldr; of potentially one of the most important scientific announcements of the last 100 years.
I gather that they wanted to include last minute data, but given that they're livestreaming this and tons of people are watching, it was a huge chance to get a decent presentation done that would at least highlight the important results clearly rather than having them be throwaway lines between jargon.
And now it has been confirmed to 5 sigma. :)
Designer sits in coffee shop wearing his hipster outfit drinking his hipster coffee, writing incensed blog post about the outrages of Comic Sans.
Physicist makes presentation on what is clearly a state-of-the-art advancement in the progress of high-energy particle physics (and thus, physics) to a world-wide community, live, and NOT a fuck was given as to what font is used. :P
Much respect to the latter folks.
Fabiola would likely rather spend her time improving the quality of her analysis, which is undeniably more valuable to the scientific community than agonizing over the font.
Does anyone have something like a buffered stream on a delay so I can be sure I don't miss anything, even if I have to stop to buffer more of the stream?
I have a vanilla, chrome browser, and a fairly recent VLC.
http://www.guardian.co.uk/science/blog/2012/jul/04/higgs-bos...
If that's choppy, save it to disk with rtmpdump: rtmpdump -v -o cern1_900.flv -r rtmp://cern.fc.llnwd.net/cern/cern1_900
edit: alternate bitrates (thanks to Brajeshwar): cern1_900 cern1_600 cern1_300
Nobel prizes all round!
Edit: “Evidence” usually means a 3-sigma signal, which existed last December, “Proof” would be a better way to describe a 5+ sigma signal, if that’s what the combined CMS/ATLAS data shows - http://www.math.columbia.edu/~woit/wordpress/?p=4809
That corresponds to 99.99994% confidence on a standard null hypothesis test, and is the usual threshold in physics for considering something proven.
http://physics.stackexchange.com/questions/8752/standard-dev...
It means a statistically very very significant number of physicists are getting laid tonight, around the world. ;)
Do they know that it's a boson not ferminon? Do they know that's elementary particle?
It is not that difficult to setup the whole streaming with lots of free and open source solutions available today. It's just a good means to a useful end.
EDITS:
Just as I suspected, it's using a Media Server Streaming Server. "rtmp://cern.fc.llnwd.net/cern/"
It is also automatically streaming corresponding quality depending on the user's bandwidth.
{ bitrate: '1000', width: '640', file: 'cern1_900' },
{ bitrate: '700', width: '640', file: 'cern1_600' },
{ bitrate: '400', width: '640', file: 'cern1_300' },
So far, I haven't found a decent way to do that in HTML5 without having to encode multiple video-streams for multiple bitrates.Unfortunately I was unable to listen in due to being on a mobile device....
To Flash or not is probably the least significant decision anyone at CERN makes.
edit: Sound is working now!
"How should we make it attractive for them [young people] to spend 5,6,7 years in our field, be satisfied, learn about excitement, but finally be qualified to find other possibilities?" -- H. Schopper
Perhaps an answer to the naive question:
http://cdsweb.cern.ch/record/1127343?ln=en
https://secure.wikimedia.org/wikipedia/en/wiki/Spin_(public_...
"The cost [...] has been evaluated, taking into account realistic labor prices in different countries. The total cost is X (with a western equivalent value of Y)" [where Y>X]
source: LHCb calorimeters : Technical Design Report
ISBN: 9290831693 http://cdsweb.cern.ch/record/494264
Western discrimination is firmly in place there.
That is referring to production costs for the calorimeter, which is part of the ATLAS detector, (it picks up neutral particles IIRC.)
It doesn't refer to differentiating between work done by white people and non white people actually at CERN, which is what you seem to be implying?
"1the western equivalent value is 1'390 kCHF. 2the western equivalent value is 5'450 kCHF"
http://lhcb.ecm.ub.es/spd/spd/General%20information/spd_cost...
It is not from the ATLAS experiment, but of another LHC experiment -- but still within the organisation of CERN.
The comment/quote is about evaluating people -- ie. by the simplest budgeting metric, labour cost (with obvious consequences for peer evaluation). It has nothing to do with colour but with peer evaluation of equivalent work, differentiated according eastern or western membership.
edit: unable to reply to the comment below. But I can cite concrete case(s) in which work was performed in Geneva by both eastern and western member within the same group. China isn't a memberstate anyway.
There's no big conspiracy here by CERN, just different wages in different countries.
The cited document (did all the downvoters also take their time and actually read the TDRs and papers in detail??? Or are they just ignorant sheep?) is a rare case of putting the facts on the ground down in a written and approved document, despite being taboo in an organisation touting "equal opportunities" and such policies.
No downvotes will change the situation I warn about above, quite to the contrary: may my previous comment serve as a warning to all non-westerners at CERN for the time being.
The moment one experiences the consequences of such discrimination, things get far more real than an absurd conclusion you are alluding to.
Would you think, that this evaluation scheme has any consequences to peer evaluation within the same group? [aside from the inherent bias, not even mentioning all the other loopholes with categorisations such as Scottish (read western) MC-EST/PhD etc.]
...inconvenient truth?
What makes it even worse, is that the worse comment is actually factual.