Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×

Comment Cheapest Ticket (Score 4, Interesting) 819

The only way this would work is to place height restrictions on the different classes of seat. I'm an academic and when travelling for work I have to purchase the cheapest ticket. Without a height restriction I would then be forced to purchase a ticket for a seat I physically could not sit down it (I already have to pull out the magazines on US carriers to allow blood flow to my feet).

This can then open the debate about whether it is reasonable for an airline to charge someone extra just for being tall - something they had no control over and which is gender-biased. After all they don't charge more to provide special meals for those with dietary preferences or religious beliefs and, with the exception of medical conditions, that is a voluntary choice. Nor, I hope, do they charge disabled passengers extra for transporting wheelchairs etc.

Comment String Theorists (Score 4, Insightful) 202

Well, this method comes from physicists.

Clearly string theorists since, according to the summary, it creates a "dodecadron" cross-section. So having a cross-section somewhere between a 2D dodecagon and a 3D dodecahedron it clearly relies on converting the block into some multi-dimensional object with a strangely dimensioned cross-section.

Comment Corporate "laws" (Score 4, Interesting) 158

Takes some seriously Orwellian doublethink to pretend copyright enforcement isn't censorship.

I think this is the result of a very narrow view point when making the map. They seem to only care about censorship by the state through direct laws. Increasingly in the US, and so some extent the rest of the western world, it is not government which restricts our rights but companies. They need to make a second map showing countries where companies have used laws to force, or bully, people into being censored through the threat of massive financial penalties.

Comment Re:No, there is no evidence of BSM yet (Score 1) 97

Actually that's not correct. The SM specified neutrino masses as zero just as it does the photon and gluon masses...or would you argue that those are free parameters as well? However I'll grant that this is not exactly a major change which is why I asked specifically about neutrino oscillations. This introduces 4 entirely new free parameters which were never included in the SM and while oscillations require that neutrinos have a mass the reverse is not true i.e. even if you give neutrinos a mass they do not have to oscillate. Hence I see no possible way that you can call this anything but new physics beyond the SM.

Comment Whoa there: many corrections! (Score 5, Interesting) 97

Since Einstein, we know gravity is the curvature of space-time. It may be represented as a force in calculations but in reality there is no force.

How about I turn that around and say that Einstein showed gravity can be modelled by the curvature of space-time but in reality it is a force? The fact of the matter is that, at a fundamental level, we have no clue what gravity is. However you can represent it very well by a spin-2, mass-less particle which couples to a particle's 4-momentum (the caveat being that you cannot make this theory work without an energy cut-off at some scale for which there is no justification). Until we solve quantum gravity we simply do not know what gravity really is but, if I were to bet, I suspect the latter is closer to the truth but needs some correction for the quantum structure of space-time which is something we have no clue about.

If gravity is not a force then do we really have a hierarchy problem?

Yes, and if anything it would be worse. The current problem comes about because we cannot scale the Higgs corrections up to the Planck-scale where we know there is new physics. If we remove that scale then we have a theory which has no upper scale limit and so should generate infinitely large corrections to the Higgs mass i.e. we go from an incredibly unlikely 1 in ~10^34 chance of the corrections giving such a light Higgs to a zero percent chance of the theory giving a light Higgs, or any Higgs with a non-infinite mass.

Obviously, if this is the case, G has nothing to do with Fermi's constant and we should not compare the two.

You are getting your 'g's and 'G's confused. In the muon g-2 experiment the 'g' is the muon's anomalous magnetic dipole moment. This is a precision test of Quantum Electrodynamics. The high order corrections to this will involve Fermi's constant (G_F) due to W and Z loops but these contributions will be incredibly small and were this any other experiment I would have said negligible but perhaps not in this case given the incredibly high precision involved. Neither of these constants have anything to do with the gravitational constant (G) nor the local acceleration due to gravity (g). So we are not comparing the two.

Comment Re:Neutrino Mass (Score 5, Informative) 97

As someone who has not been involved in neutrino physics (at least until very recently) I'd agree that neutrino oscillations are the first physics discovered that is beyond the Standard Model. In addition even if the g-2 experiment gives a 5 sigma discrepancy it tells you very little about what any possible new physics - to do that you have to produce the new particles directly and study them.

The corrections to the muon g-2 experiment are now so high order that they involve QCD loops. These are non-perturbative and incredibly hard to calculate correctly so all a 5 sigma discrepancy may mean is that the theorists have got the calculation wrong. Indeed this has happened before with a 3 sigma g-2 'signal' going away after an error in the theory calculation was found by the student of one of my departmental colleagues.

If I show my bias then I would say that the best chance of new physics is the new LHC run starting in March 2015 where we have almost twice the energy of the previous run and higher luminosity. This should at least double the reach of the LHC for new physics over the next 3 years. After this run any sensitivity gains to new physics will come from increasing luminosity and so take far longer to achieve, perhaps giving one more doubling of the reach but over the next ~15 years and with a lot of work involved since the high luminosity LHC upgrade has incredible background rates!

Comment Only a 0.0248% chance (Score 3, Insightful) 123

Everything I've read said it's very unlikely to hit Earth in 2880. One chance in three hundred does not "likely" make.

Especially since it is actually 1 in 4,000 or 0.0248%. Still I'd actually think it would be a good thing to have the odds a lot higher, like 90%, with a lead time like this of 800+ years. To date the existential threat posed by wars have caused science to make massive advances but this has come at a huge cost of misery and death

Think of the scientific advances that could come from an existential threat that, instead of pitting us against each other, actually puts all of humanity on the same side for a change. In the past 800 years we have come from the dark ages to the internet age. If we can't get it together enough to develop the technology needed to cause a small deflection to an asteroid in the next 800 years then I'd say it was probably time for evolution to give it a second roll of the dice.

Slashdot Top Deals

It's a naive, domestic operating system without any breeding, but I think you'll be amused by its presumption.

Working...