I have seen in different science fiction use Cosmic Strings (1-dimensional defects in spacetime) as weaponry, and it made me interested to make the most feasible way to weaponise them. Of course, I understand that Cosmic Strings are extremely dense, with a few inches being able to weigh as much as a mountain. So, it is unlikely that they can be used as a cutting weapon.
So instead, I had another idea to weaponise them, that sounds more feasible. I imagined a satellite inbuilt with multiple high-power particle accelerators that can accelerate and collide particles to the point that the surrounding space becomes as energetic as it was during the electroweak (or even GUT) epoch, and through spontaneous symmetry breaking, creates the cosmic string. The cosmic string is (roughly) 1 cm long, and immediately as it is created, it descends down to Earth like a meteor or a rocket going through re-entry.
Surely such a cosmic string would bear insane amounts of kinetic energy. But what would be the specific effects upon collision with the Earth? Just what happens?
PS: Do not ask too much about the accelerators. Just assume they have enough energy to even emulate the electroweak or GUT epoch. Oh, and I heard about the accelerator problem, so I use some unobtainium to make these accelerators handheld, alright?