Absolute zero is measured at 0 degrees Kelvin, which equals -273.15 degrees Celsius or -459.67 degrees Fahrenheit. It is the coldest temperature possible on the Kelvin scale. For the sake of comparison, the average temperature of the universe is approximately 2.7 degrees Kelvin.
At absolute zero, atoms would occupy the lowest energy state, essentially ceasing any movement. Absolute zero is deemed theoretical and impossible to reach, though researchers at the Massachusetts Institute of Technology came close in 2003, as have other scientists. Even at temperatures close to absolute zero, matter exhibits quantum effects such as superconductivity and superfluidity. While no one person discovered absolute zero, the concept of an absolute minimal temperature was introduced by physicist Robert Boyle in 1665.