Titanic coincidence

Most accidents in well-designed systems involve two or more low-probability events occurring in the worst possible combination. When people attempt to predict system risk, they explicitly or implicitly multiply events with low probability— assuming independence—and come out with impossibly small numbers, when, in fact, the events are dependent. This dependence may be related to common systemic factors that do not appear in an event chain. Machol calls this phenomenon the Titanic coincidence [131]. ... 

Cady in World War II realized that such a mechanical resonance of a vibrating crystal could be used in frequency control. This discovery had an important influence on radio communications.Alternating electric fields, such as those generated by the radio tubes of the time, were applied to plates of piezoelectric crystals and the expansions and contractions of the plates were caused to react on electrical circuits. If the natural frequency of the mechanical vibration of the quartz plate coincided with the frequency of oscillation of the electric circuit, resonance between the two took place and energy was acquired by the mechanical oscillators. Later. Rochelle salt and barium titanate, which are each both ferroelectric and piezoelectric, were used. ° In ferroelectric crystals, the polarization or dipole moment is reversed or reoriented upon application of an electric field. Ferroelasticity is another property displayed by some crystals in which stress can cause the interconversion between two stable orientational states. These physical properties of crystals are of great use in modern technology. 

It is, of course, tempting to draw a parallel between the photo-oxidation of water at titanium dioxide and the well-known irreversibility of O2 generation at the anodes with metallic conductivity. There are, however, some indications that the pathway involving surface-bonded peroxo-titanate intermediates is not the only possible one. Recent experiments, performed with beryllium-doped Ti02 photoanodes, have shown no evidence for the formation of any perceptible amount of the peroxo spedes l This coincided with a substantial cathodic shift of the onset potential and a strong increase of the anodic photocurrent for these electrodes , suggesting a different mechanism of oxygen evolution. 

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