At https://phys.org/print445854431.html … could recent supernova explosions be responsible for mass extinctions – or some mass extinction events to be more precise. The story is in NASAs Astrobiology Magazine at www.astrobio.net … In particular two lesser known extinction events (or part extinction events as opposed to globally significant events), at 2.5 and 8 million years ago. The idea being put out to fellow scientists is that supernova explosions may have depleted Earth's ozone layer. The one at 2.5 million years ago coincided with the end of the Pliocene era. It was followed by the Pleistocene – and the inception of the ice ages. The argument revolves around the theory of supernovas emitting harmful ionising radiation – cosmic rays potentially with the capability of affecting our atmosphere and reaching the surface to effect living organisms. We are told thee was evidence of dramatic change in the fossil record at this time (the Pliocene/Pleistocene boundary) – and change in land cover globally. The geological record is said to show an elevated concentration of iron-60 (60Fe) which is a radioactive isotope produced by supernova (among other things). One problem with the idea of an extinction event at this point is that the fossil record shows a change in speciation (after the event) and a change in vegetation cover, locally. This might be explained just as easily by a movement at the axis of rotation – vegetation shifting to a different regime. For example, equatorial rain forest becoming grassland (as in the Sahel zone), and supporting a different range of animals in the process. A change in the axis of rotation would also affect the poles – and where the ice was located. Without reading the full article the full extent of extinction is not appreciated – but is there any evidence of catastrophism in the general sense.
Supernova have been said to be capable of causing mayhem on earth and Rupert Holms had a variation on this in his talk at the last SIS speaker meeting (in April). His theory is that a remnant shard of a binary star periodically causes upheavals on earth – still on its orbit in conjunction with our Sun. Supernovas have been advocated by catastrophists such as Paul LaViolette and by Firestone, West and Warwick-Smith in 'The Cycle of Cosmic Catastrophes' and supernova were at one time popular amongst some members of SIS in the past. Wallace Thornhill, in 'The Electric Universe', on the other hand has a completely different theory on supernova – and what they might be. Rather than the mainstream idea of a collapsed star he envisages supernova outbursts as a result of a cosmic z-pinch in the central column, focussed on the central star – a simple electric discharge event.