title: Theoretical considerations concerning the effect of relativistic velocities on the rate of biological processes.
abstract: Theoretical considerations were advanced on the reaction rate of biological systems in a rocket accelerated at fractional levels of the velocity of light. The values of mass increase in reacting molecules and length contraction of space under these relativistic velocities attained by the hypothetical rocket were inserted in equations of the absolute reaction rate theory. The equations employed were for the frequency of collisions, and for the internal kinetic energy of molecular reactions. Results of both sets of equations indicated that reduction of reaction rates were correlated to the mass increase. This would imply a general slowing of all chemical, biochemical and biological processes taking place. A human would suffer a related decrease in metabolic rate. Contrary to what is generally accepted, the biological aging of the space traveler under velocities bearable by humans, namely under 0.50c, would follow a pace very similar to that of an observer remaining in the resting frame of reference. With increased increments of the velocity, the space traveler would display a more intense lowering of the metabolic rate, with signs and symptoms comparable to body core hypothermia. Metabolic rates at insufficient levels to maintain the vital functions would be attained at 0.70c and higher, leading swiftly to coma and death. The presence of an endocrine dysfunction such as hypothyroidism or obesity in the space traveler would aggravate the signs and symptoms. Space travel at efficient velocities would be unbearable for a warm-blooded animal.
authors.affiliation: Biophysics Laboratory, Federal University of Minas Gerais, Brazil.
authors.forename: I F
authors.initials: IF
authors.lastname: Heneine
mesh_terms: D000054:Acceleration; D000375:Aging / Q000378:metabolism*; D001481:Basal Metabolism; D055592:Biophysical Phenomena; D001703:Biophysics; D001831:Body Temperature; D018534:Earth, Planet; D006801:Humans; D008954:Models, Biological; D008967:Molecular Biology; D013026:Space Flight; D013997:Time Factors