Today is the autumn equinox in the northern hemisphere, so here's a look at the chemical cause of the yellows, oranges and reds in the fall foliage we'll be seeing shortly! https://wp.me/p4aPLT-sn
@alex It is the equinox everywhere on Earth today, but it's only the *autumn* equinox if you're in the northern hemisphere, where we're moving from summer to autumn. By contrast, people in the southern hemisphere are moving from winter into spring. @compoundchem