zero kelvin

Nice you must ask kelvin this question mate

But one thing for sure he predicted that the molecular activity was decreasing exponentially with decrease in temperature

He formed an equation governing the timely action

The equation when sold for no motion at all was assumed to be 0K

But it's equivalent to Celcius scale was calculated using 0deg C as a reference and never -273.15C as you have asked

When the molecular activity was found to be about 273.15 times higher than the zero level Scientist fixed Zero Kelvin nearly around -273 C

But till date there has not been any setup to achieve this in laboratories