James S. Trefil

The Origin of Life : A case is made for the descent of electrons

As the frontiers of knowledge have advanced, scientists have resolve one creation question after another. We now have a pretty good understanding of the origin of the Sun and the Earth, and cosmologists can take us to within a fraction of a second of the beginning of the universe itself. We know how life, once it began, was able to proliferate and diversify until it filled (and in many cases created) every niche on the planet. Yet one of the most obvious big ques tions?how did life arise from inorganic matter??remains a great unknown. Our progress on this question has been impeded by a formidable cogni tive barrier. Because we perceive a deep gap when we think about the differ ence between inorganic matter and life, we feel that nature must have made a big leap to cross that gap. This point of view has led to searches for ways large and complex molecules could have formed early in Earths history, a daunting task. The essential problem is that in modern living systems, chemical reactions in cells are mediated by pro tein catalysts called enzymes. The in formation encoded in the nucleic acids DNA and RNA is required to make the proteins; yet the proteins are required to make the nucleic acids. Furthermore, both proteins and nucleic acids are large molecules consisting of strings of small component molecules whose synthesis is supervised by proteins and nucleic acids. We have two chickens, two eggs,

Theoretical considerations on the extraction of pp cross sections from cosmic ray absorption data

Abstract It has been suggested, based on the application of Glauber theory to proton-air collisions, that a proton-proton total cross section which rises with energy as 1n2s is consistent with cosmic ray data. We show that if instead of a constant width, one uses a pp diffractive width which decreases consistent with present data, the cosmic ray data continue to rule out constant σppT. However, the size of the derived pp cross section is somewhat sensitive to the width, and in the relevant energy range 15% uncertainty in σppT is the maximum consequence of uncertainties in the width. Repetition of these experiments on different nuclei is not a particularly useful way to resolve these width-dependent effects.

Predictions for inclusive particle-nucleus reactions at accelerator and cosmic ray energies

Abstract Using a recently developed theory of inclusive scattering on nuclei and the assumption that the primary collision mechanism is incoherent (e.g. multiperipheral), we derive some quantities of immediate experimental interest in inclusive hadron-nucleus scattering.

A semiclassical theory for ionization by grand unification magnetic monopoles

Abstract The ionization loss by grand unification magnetic monopoles is studied. It is shown that for the velocities of interest this ionization is not large, so that monopoles of mass 1016 GeV could well have gone undetected until now.

Achieving Geological Literacy.

The course “Great Ideas in Science” was developed for undergraduate nonscience majors at George Mason University in response to concerns about the scientific illiteracy of most graduates. The course emphasizes a few key overarching concepts in physics, chemistry, geology, and biology in order to introduce students to the essential aspects of science without getting involved in the complex vocabulary or rigorous mathematical derivations. Key earth-science ideas, for example, include plate tectonics, earth cycles, and evolution. This approach is advantageous because it incorporates and integrates ideas in several sciences, it fosters an appreciation of science as an ongoing process, and it encourages the use of current events as illustrations of general principles.

On diffractive channels in absorptive eikonal models

Abstract We investigate the effects of intermediate diffractive states on elastic scattering and diffractive production in the framework of an eikonal model. Multiparticle production in the guise of the eikonal function restricts the diffractive coupling. We discuss bounds on the ratios σ el σ T and σ dif σ T .

On the interpretation of white star events in emulsion

It is shown that events in emulsion which have no heavily ionizing tracks and which are sometimes assumed to be associated with hydrogen nuclei are in fact dominated by coherent production from heavy nuclei in the emulsion. This mechanism explains the dramatic increase of such events with energy.