That’s a great question! Zero degrees Kelvin (or Absolute Zero) is physically impossible to reach because a (literally) infinite amount of work would be required to cool something that cold. We can get a few billionths of a degree away from it, but we can’t reach it. We have been able to measure temperatures down to −240°C in craters on the moon (❄brrrr❄).
answered on 8 Nov 2018:
last edited 8 Nov 2018 8:58 am
Very low temperatures can be measured using specialised thermometers.I am not sure if it possible to obtain absolute zero.
Absolute zero doesn’t really exist. A particle at absolute zero would have no energy. According to quantum mechanics – all particles have a things called “zero-point energy”. At those scales – the concept of temperature the way we think of it becomes meaningless.