Biological scaling and physics

Kleiber’s law in biology states that the specific metabolic rate (metabolic rate per unit mass) scales as M^-1/2 in terms of the massM of the organism. A long-standing puzzle is the (-1/4) power in place of the usual expectation of (-1/3) based on the surface to volume ratio in three-dimensions. While recent papers by physicists have focused exclusively on geometry in attempting to explain the puzzle, we consider here a specific law of physics that governs fluid flow to show how the (-1/4) power arises under certain conditions. More generally, such a line of approach that identifies a specific physical law as involved and then examines the implications of a power law may illuminate better the role of physics in biology.     

Tumour physics

During the cell division dynamic processes take place, the origin of which are to find in the physical characteristics of cell components. The most important characteristics are the electrical charge and the energy of the moving base components in a viscous cytoplasm. The interactions between the components lead as well known, to the emergence of hydrogen bonds between two DNA strands. The computations show that the strength of these bindings depends on three factors: first it is dependent on the length of a monotonous sequence, second it is dependent on the viscosity of the cytoplasm, and third it is dependent on the replication speed. In the study in detail is stated, how it affects the effectiveness of the DNA repair mechanism, mutation susceptibility, and thus also affects the cancer susceptibility.     

Between local cultures and national styles: units of analysis in the history of electroencephalography

The history of the discovery of the human electroencephalogram (EEG) and the ensuing implementation of electroencephalography is characterized by striking national differences. The first publication on the EEG in 1929 by the German psychiatrist Hans Berger was met with skepticism. Substantial work in this area did not start before the public demonstration of the EEG by the British neurophysiologist Edgar Douglas Adrian in 1934. Soon afterwards, many groups specialized in the new method, particularly in the US, whereas interest remained more limited in France and Britain. A comparative analysis of the rise of electroencephalography has certainly to account for such national differences, but the trajectory of the implementation of this technology calls for an investigation of local research cultures in order to identify units of productivity and to understand the dynamics along this trajectory.     

Uncertainty in physiology and physics

It was hypothesized in an earlier work that sensory perception can occur only when the perceiving system is uncertain about the nature of the event being perceived. In the absence of any uncertainty, perception will not take place. The response of the sensory afferent neuron (impulse transmission rate) was calculated using Shannon's measure of uncertainty or entropy. It will now be shown that when the event being perceived is the position and momentum of a particle, Shannon's measure of uncertainty leads to the Heisenberg Uncertainty relationship.     

Analogies between physics and biology

Considerations about fundamental relations between physics and biology are continued. So the base of this new hypothesis is finished and can be discussed.     

The physics and neurobiology of magnetoreception

Diverse animals can detect magnetic fields but little is known about how they do so. Three main hypotheses of magnetic field perception have been proposed. Electrosensitive marine fish might detect the Earth's field through electromagnetic induction, but direct evidence that induction underlies magnetoreception in such fish has not been obtained. Studies in other animals have provided evidence that is consistent with two other mechanisms: biogenic magnetite and chemical reactions that are modulated by weak magnetic fields. Despite recent advances, however, magnetoreceptors have not been identified with certainty in any animal, and the mode of transduction for the magnetic sense remains unknown.     

The synthesis of physics and biology

The hypothesis of a qualitative new field permits the prediction of a new fundamental constant. With this constant a relation between c and h can be found. The new constant permits not only a system of physics but also a new transition from physics into biology.     

The physics of light and sunlight

The physical properties of light, both natural and artificial, play a significant role in its interaction with humans. Although there is a yet-to-be-explained duality between light as waves and light as photons, we do understand many of the characteristics of light that affect living things. Here I review the general history of light and its properties, especially those that affect human health.     

Brain and physics of many-body problems

Summary On the basis of a recent physical theory of many-body problems developped in our Institute, a model of the brain is formulated, and it is shown how some of its typical features, such as learning and memory processes, find therein a natural and simple explanation. In the Appendix a short surview of the necessary mathematical formalism is finally given.A brief outline of the model presented in this paper was unformally given by one of the authors (L.M.R.) at the I.S.P. Neurosciences Research Program; Boulder Colorado, in July 1966.This work has been sponsored in part by: Air Force Avionics Lab., Research and Technology Div., Wright Patterson Air Force, Air Force System Commend-U.S.A.F.-Government of United States of America. Contract No. AF 33(615)-2786.     

Principles of environmental physics

Book Review

Principles of environmental physicsJ.L. Monteith and M.H. Unsworth Second edition. London: Edward Arnold, 1990. xii + 291 pages. £30.00 (hardback), £14.95 (paperback). ISBN 0-7131-2931-X