USA Today Magazine (November 2009)
“The real tipping point for civilization is the beginning of another Ice Age–not a world a few degrees warmer.”
USA Today Magazine (November 2009)
“The real tipping point for civilization is the beginning of another Ice Age–not a world a few degrees warmer.”
Emergent behavior that appears at a given level of organization may be characterized as arising from an organizationally lower level in such a way that it transcends a mere increase in the behavioral degree of complexity. It is therefore to be distinguished from systems exhibiting chaotic behavior, for example, which are deterministic but unpredictable because of an exponential dependence on initial conditions. In emergent phenomena, higher levels of organization are not determined by lowerlevels of organization; or, more colloquially, emergent behavior is often said to be “greater than the sum of the parts”. The concept plays an especially important but contentious role in the biological sciences. This essay is intended to demystify at least some aspects of the mystery of emergence.
(This is an updated and expanded version of the original post with some portions rewritten to enhance clarity.)
Physics & Society Vol. 38, No.3 (July 2009). Coauthored with George S. Stanford.
Three initiatives that the Obama Administration can undertake that would greatly increase nuclear stability and enhance the non-proliferation regime for many years to come.
The role of the North Atlantic Oscillation, the Pacific Decadal Oscillation, volcanic and other aerosols, as well as the extraordinary solar activity of the late 20th century are discussed in the context of the warming since the mid-1970s. Much of that warming is found to be due to natural causes.
A somewhat abbreviated version appears in Energy & Environment Vol. 23, No. 1, p. 95 (2012)
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USA Today Magazine (May 2009)
The U.S. is bogged down in tactical responses to Taliban initiatives. Little by little, the Soviet experience is becoming more and more relevant.
Essays in the Philosophy of Humanism Vol. 17 (1), Spring-Summer 2009
Creationism and Science
As fundamentalist religious thought strengthens its hold on U.S. politics, and increases its role in politics around the world, enlightened values that form the very foundation of modern society are coming under attack. In the United States the wedge issue being used by fundamentalists is a pseudo-debate over creationism and Darwin’s theory of the descent of man.
Seawater pH and anthropogenic carbon dioxide is the first chapter in Climate Change, Ed: Siddhartha P. Saikia (International Book Distributors 2010).
In 2005, the Royal Society published a report titled Ocean acidification due to increasing atmospheric carbon dioxide. The report’s principal conclusion “that average ocean pH could decrease by 0.5 units by 2100” is demonstrated here to be consistent with a linear extrapolation of very limited data. It is also shown that current understanding of ocean mixing, and of the relationship between pH and atmospheric carbon dioxide concentration, cannot justify such an extrapolation.
(Typos in Eqs. (1) and (A10) have been corrected)
Foundations of Physics Vol. 38, pp. 959-968 (2008)
The original publication is available at www.springerlink.com
http://dx.doi.org/10.1007/s10701-008-9245-x
It has been shown that for the Reissner-Nordstrom solution to the vacuum Einstein field equations charge, like mass, has a unique space-time signature [Found. Phys. 38, 293-300 (2008)]. The presence of charge results in a negative curvature. This work, which includes a discussion of effective mass, is extended here to the Kerr-Newman solution.
The assumption that the vacuum is the minimum energy state, invariant under unitary transformations, is fundamental to quantum field theory. However, the assertion that the conservation of charge implies that the equal time commutator of the charge density and its time derivative vanish for two spatially separated points is inconsistent with the requirement that the vacuum be the lowest energy state. Yet, for quantum field theory to be gauge invariant, this commutator must vanish. This essay explores how this conundrum is resolved in quantum electrodynamics.
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Essays in the Philosophy of Humanism Volume 16(1) Spring-Summer 2008.
Pope Benedict XVI interleaved two themes in his talk at the University of Regensburg on September 12, 2006. These are discussed here in two separate parts: Truth, Faith, and Reason and The Dialogue of Cultures. The first addresses the Pope’s proposal to expand scientific reasoning to include the “rationality of faith”; and the second with the threat of radical Islam, and whether a “dialogue of cultures” is possible if the West persists in its belief in what the Pope calls a “reason which is deaf to the divine”.