New Theory of the Earth

www.physicstoday.org Treaty on the Non-Proliferation of Nuclear Weapons (NPT), and to stop nuclear terrorism. One issue concerns the Comprehensive Nuclear Test Ban Treaty (CTBT) for which the US Senate declined to give its advice and consent in 1999. Since then, the UN General Assembly has elected five times to support the CTBT, with a cumulative vote of 870 to 7 (5 negative votes for the US, 1 for Palau, and 1 for North Korea). The September 2007 conference intended to encourage the CTBT into force had 106 nations in attendance, including Iraq, Iran, Pakistan, China, and Russia—but the US, India, and North Korea were absent. I believe the viability of the CTBT affects the viability of the NPT. Bernstein’s complex book is well crafted, and his descriptions are insightful; I caught only a couple of minor errors. For example, does the photo on page 22 depict Enrico Fermi joking about the fine structure constant? I was glued to Nuclear Weapons, even after having read Rhodes and other authors. It is sobering to realize that without the existence of a rare isotope (uranium235) of a moderately rare element or the use of many particle accelerators, we would not be confronted by a global nuclear threat. Nuclear physics is less studied today than it was between 1930 and 1980. Today’s new PhD-holders do not know about spontaneous fission of plutonium-240 and obtaining tritium from lithium deuteride. Nuclear Weapons should be required reading for any physics undergraduate, as it can educate the next generation on such matters. Those who want to extend their study can then move on to Rhodes’s magnum opus.