Well... at least to me, one of those is a large amount of a mass that I have some understanding of. The other is lalaland non-sense. I'd have even preferred "

Well... at least to me, one of those is a large amount of a mass that I have some understanding of. The other is lalaland non-sense. I'd have even preferred "Billion grams" over gigagram. Although a gram is really hard to intuit about, since it's basically just too small. I can probably reliably tell you if an object I pick up weighs 1kg or 2kg, I probably can't reliably tell you if it weighs 1g or 2g.