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CERN experiment discovers five new particles

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Re: CERN experiment discovers five new particles

#41

Post by M_Grey »

cynicalkane wrote: post #40
M_Grey wrote: post #33

Earlier quoted context omitted.

It's worth remembering that the Higgs particle was also predicted by the standard model, and no one underestimates the importance of that confirmation.

Not in the same way. There was no experimental evidence for the Higgs field before the Higgs was observed. These new particles arise naturally out of parts of the Standard Model that are already experimentally tested.

You're not wrong, but you'd have been really hard-pressed to find someone of significance who didn't already believe the Higgs mechanism was there. In the sense that mass exists, there was a high degree of expectation there too. It's actually quite amazing to have so many of these recent discoveries, also be confirmations. It's been over a century of this, starting with Relativity.

Re: CERN experiment discovers five new particles

#42

Post by herpdorplarp »

nonbel wrote: post #10
binarymax wrote: post #7

Earlier quoted context omitted.

Because a prediction is just an assumption (theory), and it can become a house of cards when basing future science on that assumption. Observation is proof, so future science can use that proof without worry.

Can you clarify? In my mind "prediction" != "assumption" != "theory" and "observation" != "proof" Basically I seem to disagree with everything you wrote.

By assuming validity of a theory you can make predictions. Observations provide evidence in support of this.

Re: CERN experiment discovers five new particles

#43

Post by dave_ant »

grabcocque wrote: post #12

I have to admit, I rather admire their putting a brave face on things, with their mildly-too-insistent claim that the LHC is vital for finding new physics despite the increasing likelihood it's not going to find any. In that sense the LHC is a political failure, because it has failed at its primary political job, which is to make the argument for an even bigger collider.

Well, I don't know if the LHC is a vital instrument but it will certainly decide were the community of particle physics will go after the plug is pulled on it.

The little I know about is that the LHC is an hadron collider (of course, duh), which means the collisions are not as "clean" as they were with the LEP collider, because the energy is not "deposited" on elementary particles like electrons but on composite hadrons. Which apparently makes things more complicated when it comes to know exactly how the energy is distributed inside the hadrons when they collide...

I'm not sure, I'm not an expert :) I've read that the next collider should use electrons again for collisions, up to 1 TeV or more. Maybe using linear accelerators...

Even if the analogy is not very good it's a little bit like the James Web space telescope, it will open new horizons and open the way for more precise exploration with 50m-class optically stabilized terrestrial telescopes... Just like actual 10m-class telescopes have studied Hubble discoveries in more details.

I see the LHC the same way. The results they will gather from it will decide what to explore next, with more a "precise" collider using leptons and "clean" high energy collisions.

Maybe I'm wrong though. On the political side of thing, sure, it's a costly adventure but I'd rather see money spent on those big scientific project than throwing money at military spendings and engage in useless and illegal wars.

That doesn't mean we can't debate big scientific project. ITER is also a monstrous one when it comes to budget and is even more risky because of the disruptions problem when it comes to confined unstable plasmas in a Tokamak chamber. An apparently 70 years old unsolved problem. Some physicists have warned about powerful disruptions, because of the size of ITER and induced currents in it, potentially harmful for the installation and the people that will work on it if the Tritium breeding blankets are destroyed...

Still, it will be made. And an even bigger experimental reactor is planned, DEMO, that will cost even more. I'm more sceptic about ITER than the LHC...

Re: CERN experiment discovers five new particles

#44

Post by metaobject »

dukwon wrote: post #32
shmageggy wrote: post #28

Earlier quoted context omitted.

I know what you intended, but technically O(1%) == O(100%) == O(5000%)

It's common in particle physics to express base-10 order of magnitude using this notation. I'm unfamiliar with how it's used elsewhere.

I'm guessing shmageggy thought the notation was Big-O notation. It's a bit of CS notation that defines an upper bound on the number of operations for an algorithm as a function of input size.

I don't know enough about particle physics to know whether you and him/her are even remotely close to saying the same thing.

Re: CERN experiment discovers five new particles

#45

Post by lorenzhs »

dukwon wrote: post #32
shmageggy wrote: post #28

Earlier quoted context omitted.

I know what you intended, but technically O(1%) == O(100%) == O(5000%)

It's common in particle physics to express base-10 order of magnitude using this notation. I'm unfamiliar with how it's used elsewhere.

In computer science it's used to express asymptotic behaviour. This suppresses lower-order terms and constant factors, so O(2n + log(n)) = O(n). The most common ones used are upper bounds O(•), asymptotically equal behaviour θ(•), and lower bounds Ω(•).

Re: CERN experiment discovers five new particles

#46

Post by zerebubuth »

sidlls wrote: post #38
jamesdwilson wrote: post #35

you forgot to beg for more funding

Your comment is being downvoted for a number of reasons. I'd like to use it as soapbox for a moment. One reason I left academia was the constant cycle of grant funding proposals followed by a flurry of publication followed by more proposals. These proposals often carried some requirement for language that, in my view, was a direct response to a certain kind of taxpayer, in order to justify on some tangible level the…

How much of that attitude do you think is due to a cultural shared failure to value basic science and theoretical research, and how much is due to a failure to communicate the benefits of such activities?

I think it's quite possible that when people hear "it's complicated" or "we won't see practical applications for a decade", they wonder whether it's money well-spent. Especially if funding for things which have an immediate impact (e.g: healthcare, schools) is perceived as desperately lacking.

It seems to me that the joy of discovering and understanding the universe does not get communicated to the general public, and that's a failing of those who are asking that the general public fund their research (whether individual scientists or funding bodies such as EPSRC).

Re: CERN experiment discovers five new particles

#47

Post by jamesdwilson »

sidlls wrote: post #38
jamesdwilson wrote: post #35

you forgot to beg for more funding

Your comment is being downvoted for a number of reasons. I'd like to use it as soapbox for a moment. One reason I left academia was the constant cycle of grant funding proposals followed by a flurry of publication followed by more proposals. These proposals often carried some requirement for language that, in my view, was a direct response to a certain kind of taxpayer, in order to justify on some tangible level the…

"deserve" is socialist talk. who's paying for it? why not let the market decide instead of stealing it from taxpayers?

Re: CERN experiment discovers five new particles

#48

Post by jamesdwilson »

M_Grey wrote: post #36
jamesdwilson wrote: post #35

you forgot to beg for more funding

People who just want funding don't work on things like the LHC. If you want to solve a problem while someone is throwing money at you, then you work in defense. You shouldn't be so quick to harshly judge people who are making the choice to explore the edges of what we can achieve rather than make a quick buck developing the best new way to kill someone.

right right. i am just totally making up this thing where research and results are forged, driven by state grants.

Re: CERN experiment discovers five new particles

#49

Post by ajross »

teddythetwig wrote: post #2

I assume these particles were already predicted as part of the Standard Model?

Yes. They're baryons (three-quark states). This is analogous to the discovery/synthesis of new isotopes in the middle of the last century. Technically they were "predicted", but it's still important to take the measurements. Occasionally there are surprises.

Re: CERN experiment discovers five new particles

#50

Post by whyever »

M_Grey wrote: post #33
sidlls wrote: post #19

Earlier quoted context omitted.

Yes, but these experiments serve at least three purposes. One, to verify the Model (after all, if its predictions fail in some part it will have to be revised). Another, to verify the characteristics of the predicted particles (there might be some differences from the prediction that are important, but not hypothesis-breaking). Finally, however unlikely and yet most excitingly (to me at least), to open new avenues of…

It's worth remembering that the Higgs particle was also predicted by the standard model, and no one underestimates the importance of that confirmation.

The Higgs is an elementary particle, so its discovery was much more exciting. There are a lot of particles made up of quarks, like the five mentioned in the article:

http://pdg.lbl.gov/2016/tables/rpp2016-qtab-mesons.pdf http://pdg.lbl.gov/2016/tables/rpp2016-qtab-baryons.pdf

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