The Big Bomb™

Instructions

The Big Bomb™ is an impossibly large sci fi super weapon I've cooked up that would obliterate, unbind, and scatter an entire galaxy. Yeah I have no idea what I was smoking. Now first: the object itself is 100 billion solar masses compressed to a 0.5 light year radius. This is dangerously close to its Schwarzschild radius (the point where it becomes a black hole). Even without a direct physical collision, its localized gravitational pull would strip stars from their orbits and shred solar systems via tidal forces. The Big Bomb™ travels at 0.5C (50% the speed of light) which would possesses kinetic energy that defies standard weapon classification. So how powerful would this be? FIRST: Converting 100 billion solar masses entirely into energy via E=mc^2 yields a baseline explosion of 1.78*10^58 joules. This is an energy that is comparable to an amount of energy that compares directly to the universe itself. The total visible mass-energy of our entire galaxy is roughly 4*10^58 Joules. The Big Bomb™ releases enough raw energy to perfectly match and annihilate nearly half the total mass of the Milky Way. Next it is traveling at 0.5C provides a Lorentz factor of roughly 1.15 adding another 2.76*10^57 Joules of raw kinetic energy to the blast front. This energy would propagate outward at the speed of light, instantly vaporizing stars, vaporizing planets of atmospheres, and physically pushing the remnants of the galaxy into intergalactic space The results in the total vaporization of anything within roughly 100,000 light-years, followed by a lethal radiation front that would sterilize star systems millions of light years away. NOW LUCKILY FOR US: this would not = galaxy vaporized. Galaxies are mostly empty space. Stars are separated by several light-years. Even a gigantic explosion doesn't instantly hit every star because there's simply nothing there. Instead we get a colossal relativistic fireball, enormous gamma-ray burst, huge blast of neutrinos, shockwave through the interstellar medium, the central regions get devastated, and countless stars receive enormous radiation doses. The galaxy is still screwed though. But "every star instantly vaporizes" is probably less realistic than "the galaxy is rendered gravitationally and radiatively unrecognizable over tens of thousands of years."