In case you missed it, Elon Musk called BS on the field of nanotechnology last week. The ensuing Twitter spat was admittedly rather small on the grand scale of things.

But it did throw up an important question: just what is nanotech, and where does the BS end and the science begin?

I have a sneaky suspicion that Musk was trolling with his initial nano-comment. After all, much of the tech in his cars, solar cells and rockets relies on nanoscale science and engineering.