Dihydrogenia

Dihydrogenia is a rare and poorly understood event that occurs in superfluid helium-4 under conditions of high pressure and low temperature. The term was first coined in the 1970s by scientists studying the behavior of superfluid helium, but a detailed explanation of the phenomenon has been elusive.

During a dihydrogenia event, a thin layer of liquid at the surface of the superfluid helium becomes enclosed and expands, creating a bubble of sorts within the bulk of the liquid. The enclosed layer undergoes a phase transition, changing from a liquid to a solid or glassy state. This process occurs because of the increased pressure within the enclosed layer, which in turn causes the molecules to arrange themselves in an orderly fashion.

Researchers have noted that dihydrogenia events are often accompanied by a bright flash of light, due to the sudden increase in the density of the liquid. This phenomenon has been observed using high-speed cameras and spectrographic analysis. However, the exact mechanism behind dihydrogenia is still not well understood, and further research is needed to fully elucidate the underlying physics.

Experiments to study dihydrogenia have involved creating conditions similar to those found at the centre of massive stars or in the depths of white dwarf stars, but the extraction of detailed information remains challenging. While intriguing, dihydrogenia remains an area of ongoing scientific investigation, with many questions yet to be answered.