Horizon on the Higgs tonight

No, but the theory and associated mathematics it allow us to make useful predictions of what will happen. This lets us invent things. It allows us to intelligently design things that work. With no model, it is just trial and error.

Newtonian physics has been shown to be an approximation, but it is nevertheless useful when we design bridges, buildings and other mid-size things. But to design the trajectory of a space probe or a Mars mission, we need the "better" models of special and general relativity (also used to make GPS systems accurate enough b.t.w.). The very large distances and velocities means Newtonian physics is just too coarse. Similarly, when we want to design a new transistor or integrated ciruit, or a laser diode for a CDP555, we need quantum physics. Newtonian physics just isn't "close enough" at these very small scales.

My point is that models of how things work are useful, even if we know or suspect them to be approximations. Quantum physics is just such a model. The LHC seks to better understand the behaviour of quantum-type "particles" (they're not actually particles at all but no easily comprehensible other description is very useful for our naive discussion) and will hopefully allow a refining of the quantum model, perhaps to the point where it can be "unified" with the large scale model of general relativity. These better models will then be even more useful.

That they might always be approximations doesn't diminish their usefulness.

Well said Winky.

Obviously researchers all want their work to come up with something spectacular but most results are negative although still invaluable because it means that work doesn't have to be done again.

It's not done on a "to order" basis. We'd still be living in caves if that were the case.

I watched this documentary last night. This was the first Prof. J e-K doc that I was unimpressed with. In spite of the duration of this programme, it almost completely avoided what the Higgs particle *is* (or should be) and why it is so important to qualify as the 'scientific discovery in my lifetime'. Instead we were treated to people randomly speculating whether it is 114 GeV or 120 GeV, or doing a straw poll to see if they actually believed it even existed. In a way it almost *has* to exist, just in the way that Pluto had to exist to explain the perturbation in the orbit of Uranus. Or that dark matter and dark energy have to exist to explain the otherwise inexplicable. Of course the same could be said for Faith. 

J e-K previous documentaries (Everything and Nothing, The History of Chemistry) have been very informative and fascinating and it is ironic that with his background in particle physics why were were not treated with more meat and less fluff. 

The other thing is that I might accept that they might be able to prove the Higgs does exist (but only through some arcane statistics according to the programme) but how can they possibly prove it does not?

By discovering something (as yet unknown) that is inconsistent with its existence.

Excellent, if tardy, advice.

Shock and Awe: The Story of Electricity turned out to be well structured and informative.

The standard model predicts that the Higgs Boson will appear within a certain energy range. The LHC has been scanning those energy ranges and so far, the work is about 80% complete with no firm proof of its existence. However, they have done the "easy" (relatively speaking) energy ranges first where there is little interference from other particles. If the entire energy range is studied with sufficient rigour and no evidence of the Higgs is discovered, then it will be deemed that the Higgs does not exist working on the basis that absence of evidence is evidence of absence. Whilst this does not constitute absolute proof, it is the best that can be achieved in practice.

Derry

re 'Arcane statistics'

The concept of statistical probability is central to almost all science, the 'proof' something exists (or does not) or that an effect of a treatment is true (or not) is almost never an absolute. It is based on analysis that the given observation or effect is unlikely to have occurred by chance (and that it can be reproduced too). Hence the proof of the Higgs will come if the weight of statistical evidence accumulates to make the observation of the blip on the graph almost certainly not a chance appearance. Failure to see a statistically significant blip in the energy ranges consistent with the theory means the Higgs almost certainly does not exist (at least in any way consistent with the theories). Statistics are not a fiddle here, they are what counts as proof.

Bruce

So do many sub-atomic particles exist within 95% probability? Does not seem good enough.

No. 95% probability is only good enough for medical research . In order to qualify for a scientific discovery of a new particle. The data has to be within 5 standard deviations of the mean (so-called 5 sigma significance). This corresponds to a probability of 99.99994% in the case of the LHC. They already have identified a signal which they think could correspond to the Higgs, but so far, the data has only a 3 sigma significance (corresponding to a p value of 99.73002% - this is not good enough to qualify as a discovery!).

Trevp is right but in fairness comparing the two disciplines is not really reasonable. Medicine uses 95% confidence levels generally, but biological systems have a wide degree of natural variation that is not present in a physical experiment. If 100 people all receive the same dose of the same medication the amounts absorbed, the actions and the speed with which it is metabolised and or excreted will be different in each individual.

I don't think I'll wield anything that works 99.99994% of the time!

Bruce