You are mixing up the mathematical universe with the physical (also known as real) universe.<p>For a mathematican 42 or -42 makes sense - there are no units necessary. The mathematical intepretation of a negative number is just being element of a set.<p>For a physicist 42 or -42 are pointless, because a unit is missing. The physical intepretation of a negative number is the quantified absence of a unit.<p>- by the way: <a href="https:&#x2F;&#x2F;xkcd.com&#x2F;435&#x2F;" rel="nofollow">https:&#x2F;&#x2F;xkcd.com&#x2F;435&#x2F;</a>