EDIT: Fair point below by @InclinedPlain. Neutrino oscilations were the first signal, but that does not motivate a radical extension like this evidence might.
Needless to say, most particle physicists are excited -- but we need to hold our horses -- this does not have a sufficient p-value to warrant the status of a confirmed detection -- such statistical fluctuations come and go once in a while.
Also, recent "inside" news seems to indicate that there might not be any new updates till later in the summer (rather than what the last paragraph indicates).
ATLAS observes the peak with a global significance of 2σ
5σ is the gold standard for a discovery
Just trying to determine if this is closer to "this is probably something but we will need to confirm" or "something weird happened but it's probably nothing"
The combined significance from ATLAS and CMS will be higher, but it's quite an involved process to get all the systematics right and get approval from both collaborations.
Yes, it would be, if it's not background noise.
A new particle doesn't necessarily violate the standard model in the same way that discovering a new element wouldn't necessarily violate the periodic table. It could just expand the types of predictions that it is capable of making. It is also possible that a new particle could have properties that do violate constraints predicted by the standard model, but I don't know it well enough to know whether this particular particle does so.
No, it was there from the beginning.
> The standard model makes no claim as to how many particles there can be
Nope, it does. That's kind of the whole point of it.
> what their masses should be
True, these are free parameters (except the massless bosons)
> what spin they should have
It does. Fundamental fermions have to be spin-1/2, gauge bosons spin-1 and the Higgs spin-0.
> A new particle doesn't necessarily violate the standard model in the same way that discovering a new element wouldn't necessarily violate the periodic table.
Depends if you mean a new fundamental particle or a new hadron. Discovering a new hadron is akin to adding a new element to the periodic table. Discovering a new fundamental particle means the Standard Model has to be extended or otherwise rewritten.
I was thinking of the Standard Model as more of a moving target that incorporates everything we know about the fundamental particles and their forces. I thought the model started with a smaller number of particles [photon, electron, neutrino, muon neutrino, up quark, down quark, strange quark, gluon] and was expanded over time [higgs in 64, w/z bosons in 68, charm in 70, top/bottom in 73]. After further investigation it looks like no one actually called it the "Standard Model" until all of the 17 particles known today were included, so technically there have been no new particles added to the "Standard Model"
I think considering the Standard Model a moving target is still reasonable since if a new fundamental particle were to be discovered tomorrow, we would very likely just add it to the Standard Model and still call the new version the "Standard Model". However, I also realize now that treating it in this way is probably not appropriate given the context of mojoe's original question. I would edit my original comment to retract what I've said, but it seems I took too long to recognize my mistake and it will be forever immortalized in hacker news history :(
IMO no. The standard model isn't just a table full of particles, it's much more. One core part is is the description of how these particles behave, and the lagrangian. These could change much more drastically if a new particle turned up. This is because the particles in the standard model are intimately tied with underlying representation groups, which can't accomodate another particle. It's possible folks would still call it the "Standard Model", but I suspect such a drastic change would get a new name.
no, actually the standard model would fundamentally break down. The math does not allow for such a heavy particle. No charts could save it.
The particles of the standard model are assumed to correspond to the irreducible representations (irrep) of the groups associated to the symmetries of the strong, weak and electromagnetic interactions. These groups are SU(3) (strong) and SU(2)×U(1) electroweak. The currently known particles correspond to the first few irreps of these groups, with the dimensionality of the irrep nicely matching the number of “similar” particles, see e.g. . This means that, if the above assumptions hold, finding a single new particle requires there to be yet another irrep which would imply that there are even more new particles corresponding to the other dimensions of this irrep.
 If this is even possible, I’m not quite sure, but SUSY does something similar I guess.
I don't know enough history to know if this was the case in the 1970s or 80s, but I strongly suspect it wouldn't play out this way now. The existing "standard model" has been so stable for so long (30 years or more) that it is now treated as a very specific thing. When theorists talk about possible expanded systems with additional particles, they tend to give them names: the "MSSM" is the "Minimal Supersymmetric Standard Model", for example, and if that proved to be an accurate description of our universe I think it would carry the MSSM label forever. I expect that even decades from now when we (hopefully) have a well-established broader model in place, the term "standard model" will still refer to the same low-energy sector of that theory that it does today.
There are reasonable outstanding predictions for:
- More Higgs bosons
- A Graviton
- Another 17 super symmetrical pairs to the existing 17 known particles.
- One or more dark matter particles
We don't know which (if any) of those will end up coming true, but they could all add new particles to the standard model. It is also entirely reasonable that new particles outside of the ones I listed could be added and incorporated into the model.
Suppose you have a series of 10 pairs of number coming from the universe, lets call them particles. After crunching the numbers you discover they fit perfectly in a linear function y=mx+b. Yep, two constants, one parameter and you can explain all those particles. Obviously, more particles could exist if they fit your curve, and you in fact discover, in time, 15 more of them!
Wow the model works, it predicted a bunch of awesome stuff. You and your peers name it "Standard Model" since it's so good. It's still just a name though.
Now suppose one more particle comes up and it doesn't fit the line at all. Sure you could "extend" the model by converting it to a Laplace polynomial with 24 more coefficient just to accomodate that new particle, but you can't honnestly say it's the same model anymore.
And now we found a particle but we didn't know there was a gap to fill?
The muon was discovered before an accurate prediction for it was made. There were some known gaps that people tried to fill with particles related to muons, but no one quite predicted that there was a particle identical to an electron but with a larger mass.
The tau neutrino was discovered without any prior reason to believe it existed. We knew of neutrinos and they seemed to fill the only related gaps we had. It wasn't until the tau neutrino was experimentally detected that we even realized there was a gap for it.
The tau neutrino was discovered in 2000. The discovery of the tau lepton 25 years prior heavily implied the existence of an associated neutrino.
It's really cool in practice but the way you phrased it makes it sound dreadful :)
It's on topic, the answer would be interesting, and it's stimulated good responses.
The reality is that these discoveries are important in themselves for furthering science. The applications come at a later point when the engineers need something with these new cool properties.
When people go around talking about "new physics", translate it into "we know absolutely nothing about this (isn't that great?)", practical applications included.
Most of these particles are short lived and pretty useless in themselves. However, their discovery led to a theory around them, and that theory might be useful for things like quantum computation. Or not. Hard to predict.
It's not in the "Mr. Fusion" stage, of course, but pretty neat nonetheless.
Can anyone shine a light on why the particle accellerator needs recess?
"At peak consumption, usually from May to mid-December, CERN uses about 200 megawatts of power, which is about a third of the amount of energy used to feed the nearby city of Geneva in Switzerland."
Confirmed by http://phys.org/news/2016-01-winter-therapy.html.
Also makes sense to have your annual shutdown when electricity prices are likely to be high: I'd guess that heating has a higher impact on these than air conditioning in Switzerland.
The shutdown is in winter because CERN's budget is limited, and electricity is cheaper in the summer.
Eh... despite what the other guy is saying, you can't really say this for sure. These bumps appear in a region that was accessible during Run 1 at 7 and 8 TeV.
See figure 3: http://arxiv.org/abs/1504.05511
If it is something real, and not just a statistical fluctuation (that's a big if), then it would have to be e.g. some decay product of a much heavier particle to account for why it wasn't seen during Run 1.
> If so, should they now be able to repeatedly get these results again and again?
Again, depends if it's a real effect or a fluctuation.
EDIT: I just noticed that this is also linked in the article.
I know I'm like an old man screaming into the wilderness, but I can't be the only one that's profoundly sad that even nature.com has to resort to this sort of horrible clickbait formulation for a headline.
Notwithstanding my aesthetic dislike of it, the thing about these headlines that makes me really upset is the fact that they aren't actually telling the truth.
Not to be pedantic, but they have not observed any particle physicists with an unusual amount of saliva, presumably. There is no anecdotal or visual evidence of people drooling, nothing.
It seems to me this is like the most horrible way to start off an article in a publication that is about the scientific method for gods sakes, where precision and accuracy is sort of the whole point.
Would it really be so hard to have a headline like "Shocking and unexpected evidence of a new particle" or something similar that actually says or at least approximates what the news is?
"They have tried to recreate dark matter, reveal extra dimensions of and collapse matter into microscopic black holes."
The missing word was slightly irksome. I find the claim that anyone has intentionally tried to create microscopic black holes bombastic.
CERN's own site:
"According to the well-established properties of gravity, described by Einstein’s relativity, it is impossible for microscopic black holes to be produced at the LHC. There are, however, some speculative theories that predict the production of such particles at the LHC. All these theories predict that these particles would disintegrate immediately. Black holes, therefore, would have no time to start accreting matter and to cause macroscopic effects."
They have certainly looked into it for safety sake but if CERN's intent was to create microscopic black holes, I suspect it would be a very different machine.
Actually, when I worked at CERN there was never much fuss about such risks. The tunnel is just 100 m under, but I've yet to hear from someone worried about his house being sucked in.
It still leaves me wondering what experiment at the LHC has attempted to reveal extra dimensions of, and collapse matter into a black hole. I have not been able to find any LHC experiments with this set as a goal, but I would love to be shown otherwise.
So journalists shouldn't even use figures of speech? That will make for much more dull language. I really think you're picking nits here. It's obvious the article means that scientists are excited by this new data, not that they are literally salivating.
And while I suppose this drumming up of support is a net good for the sciences, at least from the standpoint of future and practicing physicists, it is fairly unrelated to the significance of these kinds of discoveries. This kind of news has more in common with a breakthrough in advanced mathematics that gets far less "salivating"-type coverage than anything in physics ever will.
In other words, while this news might cause some interesting talk around the water cooler about the exciting new way the universe might be operating, it's only because folks' imaginations have been stoked in a way that I think has to be admitted is a little bit disingenuous. Headlines like this contribute to that.
Sadly, Nature has been doing this for years in their articles. Nature articles (not papers) are "popular science for scientists", and as such often use hyperbole and sensationalism and fail to communicate the actual core science. It's sad that the most-sought out journal does this :|
It's hard to go into details without being spoilerific, but: the problem is hard to solve, but you can still make very useful short-term predictions; the technology they have access to is being insanely under-utilized given their goals; and I don't believe the actions of the scientists given how they use that technology - I would expect the reaction to be the exact opposite of what ends up happening.
I left a review on GoodReads: https://www.goodreads.com/review/show/1553897979
Personally, I found the strength of TBP and DF to be the depth that Liu achieves with his plots at the highest level, and it's important to take a step back and not judge him as pure hard SF (as it seems to have been sold to you, based on your review) but as a writer of literature using SF as his medium (as might have Heinlein, PKD, or Asimov who is his clear and direct inspiration).
The science "plot holes", the suspension of disbelief were I think fair play as a base to deploy his explanation of the Fermi paradox (which is to an extent the point of the whole series). Like psychohistory in Asimov's Foundation or Batman's seeming invincibility in Nolan and Ledger's masterpiece, it helps plot development and the greater ideas about human nature, politics, information operations and so on that are put forward by the book.
The analyses of human nature, particularly of bureaucracies and destruction via inaction (to quote Admiral Rickover, "the person who disclaims responsibility is correct: by taking this way out he is truly not responsible; he is irresponsible").
What makes a good book/movie/narrative work of art? To me it is increasingly about the plot and, to quote FCH, about how long the work can make you think about it after you're done reading it. It's clearly working since it's been weeks since I've read the books and I still couldn't resist making the quip despite the increasing amount of karma it is costing me for being off-topic.
Compared to another famous recent Hugo winner, Rainbows End, I thought Liu's work was much more enjoyable, because it was technically unpolished but had a great, interesting, innovative plot (and I'm sure half of the polish went missing in translation), whilst the latter was technically impeccable if now a little dated, but had little in the way of plot; the plot was almost a frame in which Vinge was developing his ideas about wearable tech and information operations' logical conclusion. It's like Esterhase mysteriously putting on a bad Hungarian accent in Smiley's People when he was the epitome of the try-too-hard British arriviste in TTSP - you can forgive them the glitch since the core of the writing is so exceptional and both Esterhases were fabulous characters with great depth.
Liu's ability to toy with the reader and take unconventional paths is rather rare in today's crop of writers. I would draw a parallel there with many of Charlie Stross' books; the polish is not always there, but he keeps reinventing himself and (at least for me) each foray into a new genre or avenue of thought is a success (and a source of great movies and books to explore).
As a side note, I thought it was one of the few successful depictions of a truly alien culture (what you call near-Strong-AI?) in SF today (and no, I didn't think Vinge's FOTD's Hugo winning hive-dogs were truly alien: put human heads instead, set it in medieval "Ireland-Spain", and you get Game of Thrones, down to an epic fire battle before the walls of King's Landing).
As a second side note, isn't it fun to draw parallels between TBP and the real world? How do you, today, as the PLA, deal with the fact the NSA can hear and read everything except your thoughts when planning defense strategy? Suddenly the sophons don't seem so alien... I don't like tin foil hats, so I didn't try too hard to put myself in the Chinese position, but it was definitely an interesting line of thought.
I'm not sure if I buy the alien-culture, though. The Trisolarians seemed just as human as ... humans, especially given their introduction in the titular video game, and the Sophons barely seem to have a culture at all.
(I also agree about the Tines; I really love them as a species, but I hated the sequel, because I don't really care about basically pre-tech societies enough to read long fiction about them - same problem I had with Stephenson's Baroque Cycle, and the reason I haven't read any of the ASoIF novels.
Did you really think so? I can't remember where DF started, so I'm going to have to be careful with spoilers but in my view, the "game characters" were either humans (professor Ye if I remember well), or weak AI game characters programmed by the Trisolarians in an attempt to map their propaganda to humans. The game itself is an information operation: it is designed to cultivate a resistance within humanity and disinform humans psychologically in order to gain yet another edge over them militarily.
However Trisolarians themselves are a "superior civilisation" which is both helped and hindered by a particular feature of theirs which we don't have (related to the Tines, actually) and which becomes the core plot point enabling most of DF to play out (like the Wall Facer project). Sophons are just sophisticated communication devices, there to send back information to Trisolarians so they can better understand, hinder and later destroy Earth; they are not themselves strong AI (and therefore not a civilisation).
Thus what makes it interesting is the game theoretic aspect of it, and especially the treatment of information flow. Trisolarians know everything except the thoughts of humans (and, initially, they also lack the information that humans are capable of private thought).
It is not what they say (which is purposely adapted to look human) but how they react to learning bits of information that makes them a fully fleshed out alien culture (such as learning abstract concepts like deception, then figuring out the game theory of deception and altering their conversation onto the ETO accordingly).
The human fifth column goes from being a convenient tool of further aggression, to a core path to avoiding the one realistic chance humans have against the invasion. The ability of the Trisolarians to create a high quality "virtual machine of human minds" within their civilisation capable of such manipulation makes them a convincing "higher civilisation" (which is what will make the third book interesting, I bet, especially after the closure brought by DF).
Is the English translation that's out right now good enough? I've heard very mixed reviews about it - does it make sense to wait for a possible new translation, or should I just dive in?
Also, I thought that the Sophons were an AI, and that their actions on Earth were largely self-controlled - not driven by Trisolarians remotely.
The translation is as good as it's going to get. The main issue is that Liu is from the PRC and spent most of his life there. It took me years in Asia to slowly realise how differently the Chinese think from Westerners (hell, Westerners themselves think very differently just across borders - compare the worldview of a Brit to that of a Nordic or a Frenchman). If you compare Strugatsky and Asimov, you also get this huge cultural difference that is untranslatable because of the large amount of metadata bagage that Russians would already have coming into Strugatsky's work after growing up in Russia.
The book is "very Chinese", if that makes sense, which I think is what confuses people (and to me is a feature). A quick intro to what that means might be watching a few episodes of If You Are The One (非诚勿扰), a slightly crazy dating show that since the second season has had a government censor added to the panel to moderate the gold diggers; an Australian TV channel has started subtitling a bunch of episodes, although I unfortunately could never find the infamous season 1 ("I'd rather cry at the back of a BMW than smile on a bicycle"). You both get a sample of PRC normal citizen thinking and a taste of how the government is setting the tone culturally.
Thanks for taking the time to have a nice, long conversation with me about this!