"This idea is really an outgrowth of a mass extinction hypothesis developed by John Ellis, a theorist at CERN, and David Schramm of the University of Chicago," he said.ĭr. Collar acknowledges that his hypothesis is "purely speculative," especially since biological effects of neutrino impacts have never been identified. Fortunately, astrophysicists estimate that the explosion of a relatively nearby supernova is so rare that the odds are that there would have been at most one since life on Earth began some three billion years ago.ĭr. The effects of a spectacular nearby supernova would have even more devastating effects, of which neutrino damage would be only one. This, he said, would be "an insult that would be severe enough to kill a vast percentage of large animals with a frequency comparable to that of most major extinctions." Collar estimates that besides killing many animals outright, the neutrinos from a close "silent" stellar collapse would produce 12 cancer sites per kilogram, or 2.2 pounds, of body weight. Collar suggests that about once every 100 million years, a "silent" stellar collapse - one that does not produce a visible supernova explosion - may occur close enough to Earth to have catastrophic effects.īy making some assumptions based on known biological effects of different types of radiation, Dr. John Bahcall of the Institute for Advanced Studies in Princeton, N. A recoiling atom can rip deeply into biological tissue, releasing its damaging energy very rapidly along its track, destroying cells essential to life, causing mutations of DNA genetic material, and initiating cancers. When a high-energy neutrino hits an atom, it transfers most of its "recoil" energy to the atom, which then becomes a microscopic but potentially deadly projectile. Neutrino detectors built at laboratories in various parts of the world usually consist of enormous tanks of water, in which the rare impact of a neutrino produces a tiny flash of light. Collar, a Spanish astrophysicist at CERN, the European Laboratory for Particle Physics near Geneva, suggests that high-energy cosmic neutrinos spawned by collapsing stars could pose a much greater risk to life on earth than has been supposed. In a paper accepted for publication by the journal Physical Review Letters, Dr. The scientist who conceived the idea notes that the human race has existed for less than one-twentieth of this span, and the danger, if it exists, is probably remote. It may be that once every 100 million years or so, a flood of all but undetectable subnuclear particles surges through the earth, causing an epidemic of fatal cancers and genetic mutations with dire results for many species. If the hypothesis is correct, the human race itself has one more hazard to think about, a danger against which no protection seems possible. A new hypothesis based on cosmic "neutrino bombs" promises to complicate the debate still more. As an anti-missile weapon, enhanced radiation weapons can intercept and damage the electronic components of incoming warheads with the intense neutron flux generated upon their detonation.ALTHOUGH paleontologists agree that the history of life on earth has been punctuated by five great extinction events, the causes of these catastrophes, including the one that killed off the dinosaurs, are subjects of endless controversy. For example, M-1 tank armor includes depleted uranium, which can undergo fast fission and can be made to be radioactive when bombarded with neutrons. Also, the neutrons interact with the armor and can make armored targets radioactive and unusable (usually 24-48 hours). In the case of armored targets, the lethal range from neutron bombs greatly exceeds that of other weapons. However, armor and the personnel directing, it is damaged by the intense radiation of a neutron bomb. Armor, on the other hand, isn't affected by thermal effects or the blast except very near to ground zero. Although military targets may be fortified, civilian structures are destroyed by a relatively mild blast. This is because the blast and thermal effects are damaging much further out than the radiation. It is untrue that neutron bombs leave buildings and other structures intact.
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