Credit: iStockphoto
Existing accelerators have allowed scientists to investigate fundamental properties in the realm of billions of electronvolts, abbreviated as GeV for gigaelectronvolts. The LHC boosts the ante to the terascale, boasting 10 times the energy and 100 times the collision rate of the world's current accelerator heavyweight, the Tevatron at Fermi National Accelerator Laboratory (Fermilab) near Chicago, USA.
Since energy and mass are related by Einstein's famous E = mc2 equation, the more energy that goes into the collisions, the heavier the particles that can be spewed out. Physicists refer to the range of available particle energies as the 'scale'.
"There's something special about the scale that's being probed. There are good reasons to expect this particular scale to be a threshold where things should happen," says Nima Arkani-Hamed, a wunderkind theoretical physicist from Harvard University now spending a year at the Institute for Advanced Study in Princeton, New Jersey.
Speaking at the American Association for the Advancement of Science (AAAS) meeting in Boston in February 2008, string theory guru Edward Witten divided the LHC's list in two: there are all the old riddles, which have troubled scientists for decades; and the new riddles, such as dark energy, which have only recently emerged.
And these riddles have not troubled only scientists, he noted, because particle physics is really nothing more than the age-old quest to understand the fundamental laws of nature, transferred to the subatomic realm.
"Particle physics today is on the brink of a very big jump into the unknown," says Witten, this year's co-winner of the US$500,000 Crafoord Prize from the Royal Swedish Academy of Sciences for basic research in astronomy and mathematics.
Here are five of the biggest puzzles that the Large Hadron Collider stands a good chance of untangling:
1) Does the Standard Model still hold up at the terascale?
At the LHC, revelations are expected to begin squarely in the realm of the known: the Standard Model, which is the detailed explanation of the relationships between particles that make up matter – such as quarks and leptons – and particles that mediate the forces between matter – such as the photon for electromagnetism (see "The whole shebang", Cosmos 16, p62).
The Standard Model may now be taught in undergraduate courses but its predictions have never been tested in the terascale. Those tests involve probing such esoterica as the mass effects of charm and bottom quarks, 'parton shower models' and 'renormalisation group invariance'.
Because of its higher energy, the LHC will also produce familiar particles in far greater numbers than any other accelerator, allowing investigators to check interactions with increased precision.
Harvard's Arkani-Hamed says that it is far from a safe bet that the Standard Model will continue to hold up. "It's not clear how to read the tea leaves. Nature is what it is."
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