Betelgeuse might go off

[Anomalocaris]

Dangerous things neutrinos.

Which of the following would be brighter, in terms of the amount of energy delivered to your retina:

1. A supernova, seen from as far away as the Sun is from the Earth, or
   
2. The detonation of a hydrogen bomb pressed against your eyeball?
   

The supernova is brighter, by nine orders of magnitude.

The very excellent Randall Munroe.

The difference between the two distances, on a cosmic scale, are essentially zero so that's not really hard to sort out.

Think of it this way,  if you created an entire Dyson sphere around the sun built solely from quintillions and quintillions of Czar Bomba - the most powerful hydrogen bomb ever detonated by man - laid side by side like bricks in a wall,  and detonated all those czar bombas simultaneously,  the colossal explosion would be but less than one ten thousandth as powerful as a supernova.

Incidentally, it would take ball park of thousand quintillions of Czar bombas to make up a Dyson sphere around the sun.

But that may sound less amazing if you realize even an inconceivably large structure such as a Dyson sphere would actually be smaller than any candidate star about to go supernova.