Absolute zero registers at how many degrees Celsius?

The coldest possible temperature, a point where all atomic motion theoretically ceases, registers at approximately -273 degrees Celsius. More precisely, scientists define this ultimate chill, known as absolute zero, as -273.15 degrees Celsius. At this incredibly low temperature, the particles that make up matter would possess the absolute minimum amount of kinetic energy, meaning they would essentially stop vibrating and moving. This represents the lowest limit on the thermodynamic temperature scale, a fundamental concept in physics.

This concept is the foundation for the Kelvin temperature scale, an absolute scale where 0 Kelvin is set at absolute zero. The Kelvin scale was developed by the British scientist William Thomson, also known as Lord Kelvin, in the 19th century. Each unit on the Kelvin scale is equivalent in magnitude to one degree Celsius, meaning a change of one Kelvin is the same as a change of one degree Celsius. To convert from Celsius to Kelvin, you simply add 273.15, highlighting their direct relationship.

While absolute zero is a crucial theoretical benchmark, it remains an elusive target in practice. Scientists can get incredibly close to this temperature, within millionths of a degree, but reaching it fully is deemed impossible according to the third law of thermodynamics. Nevertheless, the pursuit of temperatures ever closer to absolute zero continues to be a fascinating area of scientific research, leading to discoveries of unusual quantum mechanical phenomena such as superconductivity and superfluidity.