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» Spherical cows help to dump metabolism law
Thu, 04 Feb 2010 17:00:00 EST
Apparently, the mysterious "3/4 law of metabolism" -- proposed by Max Kleiber in 1932, printed in biology textbooks for decades, and described as "extended to all life forms" from bacteria to whales -- is just plain wrong. "Actually, it's two-thirds," says University of Vermont mathematician Peter Dodds. A new paper of his helps overturn almost 80 years of near-mystical belief in a 3/4 exponent used to describe the relationship between the size of animals and their resting metabolism.

» Curing more cervical cancer cases may be in the math
Thu, 04 Feb 2010 08:00:00 EST
A third of cervical cancer cases respond poorly to standard therapy or experience recurrence, making cure difficult. A new mathematical model using information gathered by magnetic resonance imaging scans may make it possible to identify patients with non-responding tumors much sooner. These patients could then be offered aggressive or experimental therapy midway through treatment, something not possible now.

» Researcher to track spread of disease, malware and power outages
Thu, 04 Feb 2010 13:10:01 EST
An assistant professor with the Virginia Tech College of Engineering has won a $750,000 federal grant to formulate a mathematical framework that can track the spread of pandemics among populations and malware across wireless computer networks, as well as how a blackout occurring on one major power grid can cause a cascade of additional neighboring networks to fail.

» Spherical cows help to dump metabolism law: 3/4-power law is actually 2/3
Wed, 03 Feb 2010 10:29:07 EST
(PhysOrg.com) -- Apparently, the mysterious "3/4 law of metabolism" -- proposed by Max Kleiber in 1932, printed in biology textbooks for decades, explained theoretically in Science in 1997 and described in a 2000 essay in Nature as "extended to all life forms" from bacteria to whales -- is just plain wrong.

» The Real Rules for Time Travelers
Tue, 02 Feb 2010 15:30:00 -0600

People all have their own ideas of what a time machine would look like. If you are a fan of the 1960 movie version of H. G. Wells’s classic novel, it would be a steampunk sled with a red velvet chair, flashing lights, and a giant spinning wheel on the back. For those whose notions of time travel were formed in the 1980s, it would be a souped-up stainless steel sports car. Details of operation vary from model to model, but they all have one thing in common: When someone actually travels through time, the machine ostentatiously dematerializes, only to reappear many years in the past or future. And most people could tell you that such a time machine would never work, even if it looked like a DeLorean.

They would be half right: That is not how time travel might work, but time travel in some other form is not necessarily off the table. Since time is kind of like space (the four dimensions go hand in hand), a working time machine would zoom off like a rocket rather than disappearing in a puff of smoke. Einstein described our universe in four dimensions: the three dimensions of space and one of time. So traveling back in time is nothing more or less than the fourth-dimensional version of walking in a circle. All you would have to do is use an extremely strong gravitational field, like that of a black hole, to bend space-time. From this point of view, time travel seems quite difficult but not obviously impossible.

These days, most people feel comfortable with the notion of curved space-time. What they trip up on is actually a more difficult conceptual problem, the time travel paradox. This is the worry that someone could go back in time and change the course of history. What would happen if you traveled into the past, to a time before you were born, and murdered your parents? Put more broadly, how do we avoid changing the past as we think we have already experienced it? At the moment, scientists don’t know enough about the laws of physics to say whether these laws would permit the time equivalent of walking in a circle—or, in the parlance of time travelers, a “closed timelike curve.” If they don’t permit it, there is obviously no need to worry about paradoxes. If physics is not an obstacle, however, the problem could still be constrained by logic. Do closed timelike curves necessarily lead to paradoxes?

» Two More Steps Toward Quantum Computing
Sun, 31 Jan 2010 21:05:00 -0600