Tetragon

Researchers report that solar cells made from copper fault tetragonal sulfide (CFTS), a material made of abundant, low-cost elements, could theoretically reach 25.52% efficiency in simulations. The figure would put the earth-abundant material among competitive photovoltaic technologies if results can be reproduced in real devices, offering a cheaper path for solar energy production.

German progressive rock band Tetragon, who released only one album, 1971's Nature, is drawing renewed attention for 'Fugue', a rock adaptation of J.S. Bach's Toccata and Fugue in D minor. Listeners praise the track as very good, and note the band's mystery: they vanished from the scene after that single record, making them a cult name among Krautrock and obscure rock enthusiasts.