Volume 27, Number 2
Volume 27, Number 2
SOME SIMULATIONS OF THE POSSIBLE ROLE OF CAVITATION IN CATASTROPHIC FLOODS
EDMOND W HOLROYD, III
The process of cavitation in water has been involved in the damage of many types of man-made structures. Flow speeds greater than 30 m/s appear necessary for cavitation damage. Major damage can occur with flow depths of only a few meters but it decreases with flow depth, channel roughness and air bubble content of the water. A computer model predicting damage potential, calibrated qualitatively with actual damages to dam spillways, is used to indicate the locations and relative intensity of damage for several spillway profiles. While damage is more likely associated with steeply sloping channels, because of the high flow velocities achieved in them, damage can occur in nearly horizontal surfaces if there is some other mechanism for achieving the necessary flow speeds. In a hypothetical spillage of water over the rim of the Grand Canyon, there are numerous locations at which cavitation destruction of the rock would be as great or greater than the worst damage ever seen in actual dam spillway. A flow of water of only four meters (m) initial depth, approaching a rapid elevation drop of less than 100 m at an initial speed of only 10 m/s can be expected to produce major cavitation damage for a variety of natural land profiles. The process of damage by cavitation appears to be a likely mechanism for rapid removal of rock in channels experiencing catastrophic flows of high speed shallow water with little air bubble content.
CHANGING CONSTANTS AND THE COSMOS
GLENN R. MORTON
Four different theories of variable fundamental physical constants are reviewed and compared. Special emphasis is placed on problems of interest to the creationist. The number of explanations for difficult and diverse diluvial problems available from these types of theories, as well as their application to the problems of light from distant galaxies and radioactivity, makes this field a most interesting one from the creationist perspective.
ON THE VIABILITY OF VARIABLE CONSTANTS
The feasibility and implications of variations in the fundamental constants are examined. Although such proposed changes appear at present to be strongly ad hoc, it is argued that this is not a fatal deficiency. The apolgetic function of theorizing is briefly discussed. The distinction between operation and origin science is emphasized. It is suggested that more emphasis should be placed on the underlying philosophical issues.
A CHANGING VARIABLES MODEL FOR THE SPEED OF LIGHT
CAM DE PIERRE
The speed of light is thought to be a fundamental constant of physics. This paper proposes a model for allowing the speed of light, c, to be changing with time. It is shown that a decaying exponential with the appropriate boundary conditions would accommodate the apparently constant value for c that modern measurements have provided, even if the value of c is changing.