Hey everyone!
I'm writing a science fiction novel set in the far, far, future and I was wondering about some of the things I came up with- specifically some ship-borne weapons. The vessel around which the story takes place is the ICV (imperial combat vessel) Winter, a ~550 meter long corvette built by the evil-ish empire but requisitioned by a very high level intelligence organization to track down and destroy a terrorist group scouring ancient space battle sites, looking for space-time destabilization bombs. I know those are way out of conventional science, but I am actually here because I would like your opinion on some of the 'common' armaments I plan to put into the novel.
The Empire has major enemies, including an insurrection turned empire, and so major space battles are still common, usually over populated planets. Since there is only a limited amount of planets suitable for habitation, teraformed or underground, in in the various galaxies, neither side really wants to annihilate planets, even though they are easily capable of doing this. Planets are usually not heavily bombarded, so the weapons in question are mostly reserved to space battles.
The battles happen in three stages: At distances of about 7.5 billion kilometers, close to the distance between habitable planets and the outer edges of a solar system, ships are arranged in a very loose formation (out of visual range of one another) and bombard the enemy with extremely destructive weapons. The ships are equipped with extremely effective countermeasures, capable of jamming almost all incoming missiles and given the proper distance, diverting solid projectiles. They are also equipped with shields powerful enough to allow them to fly through the outer layers of a Sun like star. The weapons imperial ships mount include 500 tera-ton nuclear missiles and EMACs (ElectroMagnetic Accelerator Cannons). The smallest EMACs fire 30x10 meter cylindrical projectiles of solid depleted Uranium at just over the speed of light, resulting in about 8 x 10^27 joules kinetic energy (if I did my physics right). The idea of an EMAC on a corvette capable of negating the recoil shooting up to light speed seemed reasonable until I ran that through a calculator. Though the cannon can only fire about every hour due to the time necessary to recharge the capacitors and to cool down the coils (it is a coilgun based system) this still seems unreasonably powerful for a corvette to have. This thing makes the 500 teraton nuclear missiles (capable of easily rendering a planet uninhabitable) seem like childs play: it generates nearly 2 million teratons... probably enough to turn a planet into a fine mist of magma spread evenly throughout a solar system.
Anyways, this is the sort of weapon, were I doing a nations roleplay, I would categorically forbid anybody from using. I am definitely rethinking and redesigning the power of this weapon, and I need your input. What do you think is reasonable for an ultra futuristic empire which spans several galaxies to put as the main armament on corvettes? Are even the 500 teraton bombs still over powered?