eli5: If absolute 0 is only theoretical, how do we know what it is in Celsius and fereignheit

Question

eli5: If absolute 0 is only theoretical, how do we know what it is in Celsius and fereignheit

In: 0

Answer 1

Why is it theoretical? Something that cannot be achieved does not make it theoretical. We’ve never seen the core of the sun – but we don’t think it is “theoretical” – we’re pretty sure it exists.