The chiral anomaly is a purely quantum mechanical phenomenon that has a long history dating back to the late 1960s. Surprisingly, it has recently made a macroscopic appearance in condensed matter physics. A brief introduction to the relevant features of this anomaly is given and it is shown that its appearance in condensed matter systems must involve force-free magnetic fields, which may help explain the long current relaxation times in Dirac and Weyl semimetals.
The late 19th and 20th centuries brought a revolution in the scientific understanding of the universe around us, one whose effects are still being felt around the world as it forces people to change their conception of the universe and the place of human beings within it. Perhaps the greatest remaining mystery is the nature of consciousness itself, which has been a subject of human inquiry for at least the last several millennia. In this essay, I discuss the nature of thought and consciousness and argue that that consciousness and thought are natural biological phenomena.
Updated version (4 April 2016)
The idea that particles are the basic constituents of all matter dates back to ancient times and formed the basis of physical thought well into modern times. The debate about whether light was a wave or a stream of particles also lasted until relatively recently. It was the advent of de Broglie’s work and its implications that revolutionized the concept of an elementary particle–but unfortunately did not banish the idea of a point particle despite its difficulties in both classical and quantum physics. Some of these problems are discussed in this essay, which covers chiral oscillations, Penrose’s “zigzag” picture of particles satisfying the Dirac equation, and some ideas derived from string theory.
(with S. Fred Singer)
Many people believe that wind and solar energy are essential for replacing nonrenewable fossil fuels. They also believe that wind and solar are unique in providing energy that’s carbon-free and inexhaustible. A closer look shows that such beliefs are based on illusions and wishful thinking.
Op-Ed in The Bridge: Linking Engineering and Society (Winter 2015)
Published quarterly by the National Academy of Engineering
The key to understanding the current chaos in the Middle East is to recognize that the primary identity of its people is with their religion, sect, tribe, family — not the states formed following the breakup of the Ottoman Empire.
USA Today Magazine (November 2015)
Pope Francis’ encyclical Laudato Si. A strong and heartfelt critique of the existing socioeconomic system.
USA Today Magazine
USA TODAY MAGAZINE-November 2014
Defeat of the Islamic State cannot be achieved by solely military means and, most especially, not by Western military actions such as the air strikes—even if given the cover of a coalition containing Arab nations; nor can military operations decrease the spread of beliefs upon which radical Islam is based.
This essay examines our fundamental conceptions of time, spacetime, the asymmetry of time, and the motion of a quantum mechanical particle. The concept of time has multiple meanings and these are often confused in the literature and must be distinguished if any light is to be thrown on this age-old issue. The asymmetry of time also has different meanings that depend on context—although the fundamental time asymmetry is associated with the expansion of the universe. These and related issues are discussed in both classical and quantum mechanical contexts.
(This version has been expanded and reorganized)
The phrase “the human condition” has come to mean many things to different people, but here it simply refers to what history has shown to be the inescapable features of being human. In this essay we take a look at current trends, what they foretell for the remainder of this century, and how the characteristics that make us human might affect the evolution of those trends.
PDF: THE HUMAN CONDITION