White snails clustered on a gum bumelia tree

Steve Schwartzman

Sep 7

While photographing the great dried-out colony of basket-flowers along N. Heatherwilde Blvd. in Pflugerville on August 27th, I noticed a bunch of white snails clustered on a young gum bumelia tree (Sideroxylon lanuginosum. subsp. oblongifolium). It's the Austin area's only member of the sapodilla family (Sapotaceae). Check the Wikipedia article about this tree and you'll learn that people use more common names for it than there were snails on this one.

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Last month I linked to a video with Robert Bryce, whose book from 2020 I'm now reading: A Question of Power: Electricity and the Wealth of Nations. You can find a good summary of it in a 2021 Cato Institute article. Early on, Bryce notes that people often confuse energy and power, which are related but not synonymous. As he explains:

Energy is the ability to do work.* It is measured in joules (J), watt-hours, or British thermal units (Btu). Power is the rate at which work gets done. It is measured in watts ( W ) or horsepower. The equation for power is simple: 1 joule per second equals one watt. Which looks like this:

1 J/s = 1 W

Another way to think of these terms is to remember that energy is a quantity, such as a liter of oil or a ton of coal. Power is a rate—that is, it's a measure of energy flow over a given period of time.

If you've been away from science class for a long time, that's a handy reminder. If your education never included that information, now you know. If you're curious, you might ask a few people at random if they know the difference between energy and power. My guess is that you'll find few (if any) people who do.

* And speaking of the fact that energy is the ability to do work, a linguist will point out that those two italicized words are etymologically related. Energy comes from ancient Greek, and the -erg- in it is historically the same word as native English work. Ancient Greek had lost a w sound at the beginning of a word. If you put it back in, you'll hear how similar werg is to work.