A Sense of Scale At roughly minus 460 F, absolute zero is abysmally cold, yet at least we can imagine it. Being only a few hundred degrees below zero, it's in the realm of something we can put our minds around. This is not true of the opposite of absolute zero, the theoretical highest possible temperature. In conventional physics, this is approximately 100,000,000,000,000,000,000,000,000,000,000 degrees. In this interactive, get a taste of temperatures from absolute zero to absolute hot, and see why, for instance, even the core of the sun is relatively "chilly" compared to what many physicists believe the temperature of the universe was an instant after the Big Bang.—Glenn Elert Launch interactive