We now think that pulsars are rapidly spinning neutron stars. Over the years, scientists have come to appreciate that neutron stars are true oddballs. At their center, they are 100 trillion times as dense as water. Their magnetic fields are one billion times as intense as the sun's. The gravitational pressure in the little stars is so intense that electrons and protons fuse to become neutrons, which are packed together at incredible density.
Many neutron stars spin a dozen or more times per second, emitting jets of X-rays.
Our bibliography oozes gravitational forces . .