epostma

*Walri.

^{I'm not claiming this is more correct, just that it's funnier.}

The words in Clockwork Orange can only barely be said to be made up - they're almost the literal transliteration of the corresponding Russian words.

Nitpick, sorry. The mass increases cubically with the diameter, which is a form of polynomial, not exponential, growth.

Depending on how you do your calculations, it comes second after "don't have any children". But of course, for many of us, it's probably easier to reduce our meat consumption by 90% than to reduce the number of children we're planning to have by 90% -- so in terms of changes people are actually willing to commit to, your option is the better one.

This may be well known, but I love the criterion you appear to use for distinguishing between SF and fantasy: whether the in-world characters can explain how stuff works.