[Joe Brower]

Moltke is correct -- EM from cataclysmic events like supernova (which produce objects like neutron stars, pulsars, etc.) would propagate through the void at light speed, meaning you would have no way of having any sort of advance warning. It would be on you and that's when you'd know. Even if you had outposts that could broadcast a warning via laser beam, it could only follow behind the EM wave.

This fact alone makes this an interesting sort of threat. That, and the fact that a supernova cooking off within 20-30 light-years away from us does have the potential to cook us pretty good, as in extinct. And like I said, there's absolutely nothing to do for it.

So I think I'll just go and have a beer... $:-)

[Moltke]

So I think I'll just go and have a beer... $:-)

I just popped the cap off a nice cold bottle of Jever Pilsener.

Cheers!

[thulldud]

The authors are probably comparing this to solar flares, in which we see the flare by EM (light) 8 minutes after it happens, but the associated coronal mass ejection which causes most of the disruption comes a couple of days later, because the light travels at lightspeed, and the plasma travels much slower.

Scale that up to interstellar distances and magnitudes, and the plasma front would strike centuries, not days, after the EM pulse (be that visible or gamma).

So that is already a lot of disbelief to have to suspend just to enjoy wasting a couple of hours in front of a movie screen.