Why does a nuclear explosion form a mushroom-shaped cloud? If you would tell me why frantic and furious fusion and fission have a fondness for the fungus form, I would certainly appreciate it.

–Paul Smith, Tampa, Florida

Shame on you, Paul. You know I cringe at F-words. You don’t need an atom bomb to make a mushroom cloud, just convection. Mushroom clouds typically occur when an explosion produces a massive fireball. Since the fireball is very hot and thus less dense than the surrounding air, it rises rapidly, forming the cap of the mushroom cloud. In its wake the fireball leaves a column of heated air that acts as a chimney, drawing in smoke and hot gases from ground fires to create the stalk of the mushroom. Since the center is the hottest part of the mushroom cloud, it rises faster than the outer edges, giving the impression that the cap is curling down around the stalk. Thus the familiar fungal form.

Hydrogen bomb explosions are so huge that the cloud may reach the tropopause, the boundary in the atmosphere where the temperature begins to rise sharply. The cloud generally can’t break through this, and the top flattens out, producing an especially pronounced mushroom shape. (The tropopause also forms a ceiling for thunderheads, producing their anvil shape.)

Mushroom clouds aren’t necessarily big. One of the Teeming Millions tells me he once set off a carbide noisemaker-type cannon with the igniter mechanism removed. Out of the hole where the igniter was supposed to go there issued a ten-inch mushroom cloud with a stem of fire and a cap of black smoke. And, we must suppose, a fabulously fierce foomp.

Why is it that a young, struggling writer can pay to have his or her work printed–and it’s called “vanity” publishing. But a young film grad can write, produce, direct, and star in his or her own movie and it’s called “independent filmmaking”? Where, in art, do we cross the line from independent to vain?

–Marc Mitchell, via the Internet

No question, sometimes it’s a pretty fine line. To put it strictly in print terms, self-publishing–the equivalent of independent filmmaking–is what you do when you can’t find a regular publisher but nonetheless have some reasonable expectation of being able to sell what you wrote. Vanity publishing is when you’ve abandoned all hope.

Vanity publishers (the ones who run those Authors Wanted ads) will take a manuscript and, for a stiff fee, turn it into a book. You wind up with a garage full of printed copies, but that’s about it–promotion of vanity books is usually minimal. Vanity publishing tends to attract people with delusions of grandeur who just want to see their prose in print. (To be fair, vanity presses also print a lot of family histories and such, where making money is not the object.)

Self-publishing no doubt attracts its share of deluded souls, but it requires you to have a little more on the ball. Typically the author of a self-published book not only writes the thing but also arranges for its design, printing, marketing, and distribution. Most self-published authors are lucky to break even, but a few hit it big. Some books that were initially self-published:

The Joy of Cooking

by Irma S. Rombauer, self-published in 1931. Rombauer had a firm produce the book, but she did all the promotion. It was picked up by a trade publisher and to date has sold more than 15 million copies.

What Color Is Your Parachute? by Richard Nelson Bolles. Sold five million copies.

The Celestine Prophecy by James Redfield. Initially sold out of his car, it went to Warner Books for $800,000.

The One Minute Manager by Kenneth Blanchard and Spencer Johnson. Sold 20,000 copies before being picked up.

50 Simple Things You Can Do to Save the Earth by the Earthworks Group. Sold 3.5 million copies.

Leadership Secrets of Attila the Hun by Wess Roberts. Sold 486,000 copies.

Of course, you need some entrepreneurial hustle even if your book is published conventionally. Many a novice author has figured his work was done once he delivered the manuscript, only to have his publisher inform him (usually not in so many words), “What? You expect us to promote this?” Understandably some writers think, if I’m going to do all the work, I’m going to keep all the cash.

Art accompanying story in printed newspaper (not available in this archive): illustration by Slug Signorino.