What’s in a Unit Anyway? Part 2: When is a Kilogram Not a Kilogram?

Weights & Measures Office

In my last post, I told you about how scientists measure amazingly cool things that can be vastly different in size, like elementary particles or very distant dwarf planets and their moons. Thinking about all the units to describe length got me thinking again (uh oh)... How do scientists know that the nanometer they measure …

What’s in a Unit Anyway? Part 1: From Protons to Galaxies

question

If you’re like me, you often find yourself thinking about random things. For example, just the other day I was thinking to myself, “what’s the diameter of a gold nanoparticle* in light years**?” Unit conversions have been a thorn in my side for as long as I can remember, so I was pleased to discover …