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3) Are there still more basic building blocks of nature, heavier cousins of the known particles making up an extended family of superparticles?
Probably not. Quite a few physicists are talking about a 'Higgs package deal' at the LHC. In these scenarios, the Higgs could also be somehow linked to supersymmetry, the theory that all the 20 fundamental particles are paired with a 'sparticle'. These sparticles are replicas, except in two respects: they are heavier because of spin and exist as a kind of quantum mirror image. What does that mean? All particles are classed as either fermions or bosons.
Supersymmetry assumes that a particle belonging to one category has a superpartner in the other, making nature more balanced. The theoretical superpartner of an electron (a fermion), for instance, is known as a selectron (which is a boson).
A large part of supersymmetry's attraction to many physicists lies in its elegance – a grand dance of particles throughout the universe, of which we currently see only half. Yet there are more practical reasons why CERN's Ellis has focussed his attention on determining what readings from the collider's detectors would amount to a telltale 'signature' of sparticles such as the selectron, photino or wino (pronounced we-no).
"Why the hell should one believe in such an exotic theory?" Ellis asks, and then reels off four areas where supersymmetry would help advance the New Physics: the unification of fundamental interactions; a neutral candidate for cold dark matter; explaining why the Higgs isn't heavier than it is; and resolving what's known as the hierarchy problem – a bland label that hides deep befuddlement about why gravity is 40 orders of magnitude weaker than the three other elementary forces.
"This is infinitely more exciting than just finding some extra dimension, which I consider boring," says Ellis. "It would complicate life, but it's really only one new principle, a new kind of symmetry between particles – some with spin and some without. It's a very powerful way of solving some of the fundamental problems in physics."
Identifying evidence for supersymmetry particles depends more on measuring what's missing from the LHC's detectors than on measuring what's there. The investigators total the momentum of particles that smash and the momentum of the resulting debris. (This isn't something you can watch, since the cascade of decaying particles flashes past in 10 to 27 seconds.) If these two momentum totals don't balance, that suggests some energy has been carried away by a new type of particle that's invisible to the normal detectors.
Says Ellis: "In the New Physics the most important clue is the energy that you cannot see."
4) What exactly is dark matter, the mysterious substance that, observations suggest, is five times more common in the universe than all the visible stuff?
Just as the Higgs and supersymmetry could turn out to be conjoined twins in the New Physics, so too could supersymmetry be integral to solving The Mystery of the Missing Mass. In an embarrassing development, over the past decade scientists have come to realise that they've been overlooking about 96 per cent of the universe.
The visible "ordinary" matter constitutes a mere four per cent, according to current thinking. Observations and theory say the rest is either dark energy (about 74 per cent) or cold dark matter (some 22 per cent). Since cold dark matter emits neither heat nor light, no one has yet been able to directly detect it.
However, if ordinary matter were the only thing holding clusters of galaxies together, then astronomers say they would have long ago flown apart. There isn't anywhere near enough matter to produce the necessary gravitational pull. Ergo, the pressing need for dark matter to close the gravitational deficit.
One widely accepted hypothesis is that dark matter particles could have been produced in copious quantities in the Big Bang, and that enough of them survived until today to constitute the invisible cosmological soup.
Since the LHC has the capacity to reach energies last experienced when the universe was being born, the hope is that the colliding proton beams will recreate dark matter particles inside the detectors. At the same time, several underground detectors around the world are tuning ultrasensitive receivers to try to capture the passage of a dark matter particle.
"We have at least a chance of unravelling the mystery of dark matter," says string theory guru Witten, who does his thinking at the Institute for Advanced Study in Princeton, New Jersey.
Safety Rebuttal
Excellent quality article.
The dice with 3 sixes is a bit ominous. Some of us are hoping CERN does not roll 3 sixes when high energy collisions begin.
A number of PHD level theoretical scientists also have questions about LHC Safety.
The most notable is Professor Dr. Otto E. Rossler, most famous for his contributions to Chaos theory.
Dr. Rossler refutes CERN's safety arguments and proposes that if micro black holes are created (some say the odds are 1 in 1000, others say the odds are 1 in 2) they would grow large enough to threaten Earth in 50 months to 50 years.
Got LHCFacts?
Cosmic Roulette
Intersting article, and very well written. However it would be nice to proffer the objections to the project, as one commentator has suggested. There are two sides to every story. Howabout examining what happens if things go wrong?
A bit of "doomsday" in the article would be enjoyable for the cynics. Moreover, suppose that the negative scenario does happen, are there any procedures in place to rectify them? I mean, flipping the on-off switch isn't exactly going to make a black hole go away, if one is created.
cosmic roulette
The earth is already bombarded with cosmic rays many thousands of times more energetic than the beams at CERN. If high energy collisions were dangerous, catastrophe would have happened already.
LHC - another white elephant
The whole dark matter concept is a patch up band-aide to save big bang from the dustbin of scientific history. It is futile. Einstein’s field equations for the static vacuum gravitational field, i.e. Ric = 0,violates his ‘Principle of Equivalence’ – the equivalence of gravitational and inertial mass, and the laws of Special Relativity, cannot manifest in a spacetime which is by definition empty, that contains no matter. QED. Consequently, if his energy-momentum tensor is zero there is no Einstein gravitational field. Hence his field equations take the following form:
Gij/k + Tij = 0, (subscripts)i,j = 0,1,2,3, k = constant,
wherein the Gij/k are the components of a gravitational energy tensor. Thus the total energy of the gravitational field is always zero; the Gij/k and Tij must vanish identically; there is no possibility for the localisation of gravitational energy (i.e. there is no possibility for Einstein’s gravitational waves). Moreover, this means that Einstein’s General Theory of Relativity violates the experimentally well established conservation of energy and momentum, so if the usual conservation of energy and momentum is valid (bearing in mind that there is no experimental evidence to refute it) then Einstein’s General Theory of Relativity is invalid. Also, Einstein invented his pseudo-tensor by which he and subsequent big bangers and LIGOers and LHCers claim that his gravitational energy can be localized. However, Einstein’s pseudo-tensor is a meaningless concoction of mathematical symbols for the following reason – it implies the existence of a 1st-order intrinsic differential invariant which depends only upon the components of the metric tensor and their 1st-derivatives (to see this just contract his pseudo-tensor and apply Euler’s theorem). But the pure mathematicians G. Ricci-Curbastro and T. Levi-Civita proved in 1900 that such invariants do not exist! In addition, Einstein and the subsequent big bangers and LIGOers and LHCers resort to linearisation of Einstein’s field equations to localize his gravitational energy. This too is nonsense, because linearisation implies the existence of a tensor which, except for the particular case of being precisely zero, does not otherwise exist, as proven by H. Weyl in 1944. So the big bangers and the LIGOers and their international counterparts such as the AIGO in Australia and VIRGO in Europe, are all destined to detect nothing.
As for black hole collisions, mergers and binaries producing gravitational waves, that too is nonsense by the foregoing. To amplify, let’s assume for the sake of argument that black holes are predicted by General Relativity. The simplest black hole is the so-called “Schwarzschild black hole”, obtained from Ric = 0, which is a statement that there is no matter in the Universe. Since the ‘Principle of Superposition’ does not apply in Einstein’s theory, owing to it being non-linear, one cannot, by an analogy with Newton’s theory (where the Principle of Superposition holds), just arbitrarily insert lumps of matter into any given spacetime for his gravitational field. Now according to the black holers and gravitational wavers , two “Schwarzschild” black holes (concocted by stupidly applying the ‘Principle of Superposition’ of Newton’s theory), each obtained separately from Ric = 0 (an empty spacetime), can mutually interact in a mutual spacetime that by definition contains no matter! That is nonsense, but the simplicity of it escapes their poor brains. Furthermore, before one can talk of black hole interactions it must first be proved that the two-body problem is well-defined within General Relativity. This can be done in only two ways, (a) derivation of an exact solution to the field equations for two bodies, or (b) proof of an existence theorem by which it can be shown that Einstein’s field equations contain latent solutions for such a configuration of matter. There are no known solutions to the field equations for the interaction of two or more bodies, so option (a) has never been fulfilled, and no existence theorem has ever been proven, so option (b) has never been fulfilled either. Moreover, General Relativity has not been able to account for the simple experimental fact that two fixed bodies will approach one another upon release. So all talk of black holes interacting is nonsense. However the whole issue is moot, since black holes are in fact forbidden by the Theory of Relativity (it forbids infinite densities), and owing to the violation of the usual conservation of energy and momentum, General Relativity is invalid, and with it the alleged big bang. The LHCers various claims for bangs and holes are just plain poppycock. Finally, despite the claims that black holes have been "discovered" all over the place, nobody has ever found one because the signatures of the alleged black hole, (a) an infinitely dense point-mass singularity and (b) an event horizon, have never been found. Claims for their discover is wishful thinking, not science. The LHC is just like LIGO et al, a massive gravy train for its participants, at the great expense of the taxpayer.
More non-mathematical details are here:
http://www.sjcrothers.plasmaresources.com/Unicorns.html
For those who want the mathematical proofs, go here:
http://www.ptep-online.com/index_files/2008/PP-12-11.PDF
And here: http://www.ptep-online.com/index_files/2007/PP-09-14.PDF