One thing that we should be seriously concerned about is astronomer's nonchalant attitude in regard to their observation of the encounter of the G2 cloud with our Galaxy's core. As noted in the Galactic Pinball posting about the G2 cloud encounter, astronomers are actually hoping to see "fireworks" to learn more about how "black holes dine". They don't realize that, if the galactic core does erupt and produces fireworks strong enough to release a superwave, then the moment we see the outburst, the superwave cosmic rays will be here at our doorstep and will start to bite us. Perhaps they think that just because the Galactic center lies 23,000 light years away, there is nothing to worry about.
This calls to mind the Popul Vuh of the Quiché Mayan Indians which describes the second world as being populated by a race of wooden men who were wanting in intelligence and had no memory of their maker. It says that because they forgot about the Heart of Heaven, they were destroyed by a thick resin that fell from heaven and darkened the Earth, which was accompanied by a catastrophe of fire and tremendous earthquakes (Brinton, Myths of the New World, 1876).
Evidence that superwaves do exist in active galaxies can be seen in the case of the nearby "starburst galaxy" M82 in which astronomers have recently observed a radio source moving at the superluminal speed of 4.2c. This phenomenon is produced by cosmic rays traveling rectilinearly through the galaxy's central region at very close to the speed of light. The emissions we see are coming from cosmic rays following a trajectory aimed close to our line of site. For details about this are discussed in the recent superwave forum posting.