[ben-schaaf]

I'd consider them equally as silly, considering we're actually capable of launching rockets into space yet the closest we've gotten with a space gun is a measly 180km apogee @ 3.6km/s[0]. The original question was why we don't send our nuclear waste into space. We can't send our nuclear waste into space using a rail gun because we can't currently send anything into space with a rail gun.

Otherwise here's a good discussion on the viability of space guns: https://space.stackexchange.com/questions/2370/what-technolo....

[0] https://en.wikipedia.org/wiki/Project_HARP

[gdpgreg]

Cause someone murdered the leading scientist in the field. Also there's concerns that it'd be too easy to turn it essentially into a very long range, highly effective weapon that could lob nuclear or conventional projectiles at countries on the other side of the planet with little to no warning.

[ben-schaaf]

We already have highly effective weapons that can lob nuclear or conventional projectiles at countries on the other side of the planet with little to no warning: ballistic missile subs.