Science & TechFact
Colder than minus 273.15 degrees is impossible.
Temperature measures how much particles move. At −273.15 °C, which is 0 kelvin, thermal motion is at its minimum; physics allows nothing lower. The point can never be reached exactly, but labs get within billionths of a kelvin. For comparison, deep space sits at about 2.7 kelvin thanks to the cosmic background radiation.
Useful: Kelvin has no negative values, which is why physicists almost always calculate in kelvin.
Source: en.wikipedia.org