Underwater Vision

Abstract

31. M. L. Hair (private communication) states that, at pressures of 16 torr and above, the very rapid increase in the amount of absorbed water makes it difficult to make precise measurements, and a fairly broad range of values for the number of molecules absorbed per hydrogen-bonded hydroxyl pair may be indicated. Hair's failure to produce anomalous water may have been due to the special nature of the surface treatment, which may prevent a clustering of hydroxyl pairs sufficient to form successive layers. Fortunately all that is needed for understanding the formation process is identification of hydrogen-bonded surface hydroxyl pairs with an increased absorption under the pressure condiitons favorable to the formation of anomalous water.Hair also proposed the anomalous water geometry given in Fig. 4h, but this has a higher energy than either squares or planar hexagons. 32. Even though the asymmetric cyclic hexamer has a per-bond binding energy comparable to, or slightly greater than, tetrahedral coordination, its geometry is not favorable for formation of the normal liquid because of its very low entropy relative to the tetrahedral arrangements. 33. There is a further decrease in the free energy, due to the lower vibration frequency, hence the higher entropy, of the symmetric hexamer over the asymmetric hexamer. 34. L. Pedersen and K. Morokuma, J. Chem. Phys. 46, 3941 (1967). 35. When an anomalous-water bond is broken, the energy of the conformation immediately after breakage is close to that of a symmetric bonded chain. A concerted motion of each. symmetric hydrogen to a corresponding asymmetric position is highly unlikely because of the between-layer interconnections.

Action-Specific Effects Underwater

“…Distance perception underwater is typically overestimated relative to the same distances above ground (Luria and Kinney 1970;Luria et al 1967;Ross 1967). Researchers attribute this overestimation to optical factors such as reduced brightness contrast or seemingly increased aerial perspective.…”

Prorocentrum rivalis sp. nov. (Dinophyceae) and its phylogenetic affinities inferred from analysis of a mixed morphological and LSU rRNA data set

“…However, P. rivalis sp. nov. is present in shallow waters where PAR is restricted to the red end of the spectrum (Luria & Kinney 1970). It would be useful to study the photosynthetic pigment characteristics of P. rivalis sp.…”

Enhanced recovery of Aircrew from G acceleration induced loss of consciousness (G-LOC): A centrifuge study

“…Later research has shown that such adjustment not only extends to displacements in spatial location, but also to distortions in target form and size (25,30). In addition, other studies have indicated that observers can adapt to an even broader range of perceptual and motor aberrations including distortions in size and distartce (22,24), apparent curvature (27), and illusory motion (8) that occur underwater and the disabilitating effects produced by time-delayed visual feedback on perceptual-motor performance in virtual environment. Of particular relevance to the G-LOC problem are studies demonstrating sensory-motor adaptation to aberrations that appear in the microgravity conditions of parabolic and orbital flight (19).…”