Parallel Cannons were powerful weapons of war developed by the Time Lords. They were used in the War against the Enemy. These weapons fired a point hole towards another part of the universe into the nova of an anti-sun. This allowed the neutrinos from that dimension to pass into the normal one. The tear opened like a deluge. Physics worked differently there and the neutrinos destroyed anything they encountered. Normal matter simply fell apart under the principle of quantum shattering. Organic matter lasted a fraction of a second longer before disintegrating. If a parallel beam was left on long enough, it could eat through a world in three hours and destroy its atmosphere in nine.