In their article "From the Fundamental Theorem of Algebra to Astrophysics: A `Harmonious' Path", which appears in the Notices of the AMS, mathematicians Dmitry Khavinson (University of South Florida) and Genevra Neumann (University of Northern Iowa) describe the mathematical work that surprisingly led them to questions in astrophysics.
That's one reason why, in 1999, Lazaridis donated $100 million of his nascent fortune to seed the institute. Another, he says, is "because people take theoretical physics for granted." No kidding. This world of equations and chalk dust is about as far away as you can get from the world of commerce. Why anyone would hand over such a massive amount of money—at the time, close to one-fifth of Lazaridis's net worth—to a collection of wild-haired math freaks is lost on most of the folks on Bay Street. Sure, Lazaridis knows that quarterly earnings are important. (In its most recent quarter, RIM posted a higher-than-expected profit of $412.5 million and shipped 2.2 million new BlackBerrys, the first time in the company's history that it broke through the two-million-mark in a quarter.) But he also knows that without the kind of work being done at Perimeter, chances are slim that someone will develop another world-beating technology like RIM's 60 or 80 years down the line.
One environment in which monopoles might pop up is crystalline solids. In a crystal at a low temperature, excitations above the ground state often behave like elementary particles: they carry a quantized amount of energy, momentum, electric charge and spin. In their theoretical study, Castelnovo et al. find the first instance of such an excitation with a non-zero magnetic charge. Under certain conditions, these magnets behave as a gas of independent magnetic poles. There is even a phase transition at which a thin vapour of these monopoles condenses into a dense liquid.
The two can be chosen, according to taste, from a list of three: the speed of light, the strength of gravity, and Planck’s constant, which relates the energy to the frequency of a particle of light, say George Matsas of the São Paulo State University and his colleagues.
Once two constants have been chosen from that list, they say, those are the only parameters that need have units of measurement ascribed to them. Everything else — for example, the charge or the mass of an electron, or the strength of nuclear forces — can be described in relation to these two 'dimensional' constants.
The researchers have studied1 the aerodynamics of a flexible, rippling sheet moving through a fluid, and find that it should be possible to make one that will stay aloft in air.
No such carpet is going to ferry people around, though. The researchers say that to stay afloat in air, a sheet measuring about 10 centimetres long and 0.1 millimetres thick would need to vibrate at about 10 hertz with an amplitude of about 0.25 millimetres. Making a heavier carpet 'fly' is not forbidden by the laws of physics. But the researchers say that their "computations and scaling laws suggest it will remain in the magical, mystical and virtual realm", as the engine driving the necessary vibrations would need to be so powerful.
The university's physicists recently "put the nail in the coffin" in the debate about using fractal analysis in authenticating art as they completed a second study related to fractal analysis and Jackson Pollock's drip paintings.
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"No information about artistic authenticity can be gleaned from fractal analysis," said Katherine Jones-Smith, lead author of the study.
In a paper published online 25 October in the Monthly Notices of the Royal Astronomical Society, Moffat and co-author and Perimeter Institute colleague Joel Brownstein argue that their modified theory of gravity, which they call MOG, can also explain the Bullet cluster discrepancy. Einstein argued that gravity arises because mass warps space and time--he even came up with an equation for how the warping works. Moffat says he added "minimal" additional terms to Einstein's equation that subtly change how gravity behaves on galactic scales. The upshot is that gravity is stronger at these scales than Einstein predicted and that MOG can explain the gravity of the Bullet cluster without dark matter. Brownstein says he and Moffat have applied MOG to the behavior of more than 100 galaxies and more than 100 clusters, and in all cases, it has successfully predicted their motions "without the necessity of adding dark matter."
This week of advanced science talks at the lab culminated in a lecture by Gross who offered a note of apology about the string theory of reality, to which he has been a major contributor
"It hasn't led to any big observational payoffs," he said.
A member of LANL's Theoretical Division, astrophysicist Salman Habib said after the talk that string theory remains difficult to assess.
"It's a funny field to look at from the outside because it has yet to connect with the outside world," he said. "Mathematically, it's very pretty and theorists like to do fundamental mathematical computations, but they have not led to any big observational payoffs so far.
The annual budget for NSF's entire physics program, of which theoretical physics is only a small part, is approximately $249 million; this represents 0.009 percent of the federal budget. Our government devotes more than 1 billion dollars per week in deficit spending to perpetuate the war in Iraq.
[b]The amount that the federal government spends on curiosity-driven scientific research does not impede our nation from making progress in the day-to-day effort at improving the human condition. Our nation's misplaced priorities are much larger in scale and much harder to scapegoat[/b]. While learning about the origins of the universe or the evolution of man may not lead to more shelters for the homeless, collectively burying our heads in the sand is unlikely to have the desired effect either.
Hartnoll et al. push what one might term the 'AdS-to-high-Tc correspondence' to its logical conclusion. They study its application to a particular, rather recondite transport phenomenon known as the Nernst effect — the crosswise flow of heat and charge currents in the presence of a magnetic field7 — in the nearly quantum-critical matter of a two-dimensional cuprate system. In a theoretical tour de force, they use the physics of a black hole in a three-dimensional anti-de-Sitter space that carries both electrical and magnetic charge to guide them in the very complex derivation of the relevant transport equations directly from quantum field theory. They show that these theoretical results are seemingly consistent with a number of hitherto unexplained features of the Nernst effect in a high-temperature superconductor7.
Here, the AdS/CFT correspondence comes to the aid of the experimentalists in a similar way. The background is the observation that quark–gluon fireballs, as have been created in the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory on Long Island, behave in a remarkably simple way, but one that current theories find difficult to explain — they are governed by normal hydrodynamics, but have extremely low viscosity. Quite simply, the AdS/CFT correspondence tells us that when the quantum physics is scale invariant, the viscosity of such a system can be as small as it is. This result is far from obvious given our current understanding of quantum chromodynamics, the standard-model quantum-field theory of the strong nuclear force that governs interactions in the quark–gluon plasma.
