Bad Astronomy. Misconceptions and Misuses Revealed, from Astrology to the Moon Landing 'Hoax'

the most popular sites on the planet. When the Sojourner Mars probe landed on the Red Planet in 1997, their web site scored millions of hits, more than any other event in the history of the then-young web. Since then, the site has had almost a billion hits. When the Space Shuttle serviced the Hubble Space Telescope late in 1999, the NASA web site got a million hits in a single day. When the comet Shoemaker-Levy 9 smashed into Jupiter in 1994, the web nearly screeched to a halt due to the overwhelming amount of traffic as people tried to find pictures of the event from different observatories. Other science-based web sites report traffic similar to these examples as well.

The public not only likes science, it wants more. A survey of the reading public was made by newspapers, and they found that more people would read about science news, if it were offered, than about sports, finance, or the comics. When I give public lectures about results from Hubble, people barrage me with questions, and I usually wind up staying late answering more questions from people curious about the universe around them.

Despite their desire, a lot of people harbor some odd notions about astronomy. Come to think of it, it’s probably because of that desire. If you want something enough, you’ll take anything to fill that void. People have an innate curiosity about the universe; this is almost certainly a simple outcome of evolution. People who are curious are likely to explore, to learn, to discover. That’s a pretty good survival trait.

But if they cannot get to a reliable source of information, they’ll accept something less than reliable. People like the world to be mysterious, magical. It’s more fun to believe that UFOs are aliens watching us than it is to find out that the overwhelming number of ET sightings are due to misinterpretations of common things in the sky.

The truth can be hard, and so sometimes it really is easier to believe in fiction. Other times, the tale has just enough of the ring of truth that you might not question it. Do we have seasons because Earth moves closer and then farther away from the Sun? Can you really see stars during the day from the bottom of a well?

Over the years I have found that people tend to have a lot of odd ideas about astronomy. Those ones I just mentioned are just a few examples of the host of misconceptions floating around in people’s brains. Did I say “floating”? I mean entrenched. Like the movie scenes that ensconce themselves in our memories, misconceptions about astronomy — about any topic — take root in our minds and can be very difficult to weed out. As Cardinal Woosley said, quoted by Alistair Fraser on his Bad Science web site, “Be very, very careful what you put into that head, because you will never, ever get it out.” Far be it for me to disagree with His Eminence, but I think he’s wrong. It is possible to yank that idea out and plant a healthier one. As a matter of fact, I think sometimes it’s easier to do it that way. I have taught astronomy, and found that even an interested student can be easily overwhelmed in a classroom by a fire-hose emission of facts, numbers, dates, and even pictures relating to astronomy. There’s so much to learn, and it can be hard to find a toehold.

However, if you start with something students already know, or think they know, that toehold is already there. Do you think we have seasons because the Earth’s orbit is an ellipse, and so sometimes we’re closer to the Sun than others? Okay, fine. Can you think of something else that might cause it? Well, what else do you know about the seasons? They’re opposite in opposite hemispheres, right? Southern winter is northern summer, and vice versa. So what does that imply about our theory of what causes the seasons?

I won’t give away the answer here; you’ll find a whole chapter about it later in this book. But I hope you see my point. If you start with something already there in people’s heads, you can work with it, play with it, make them think about it. Starting with a known misconception is a wonderful hook that captures people’s thinking, and it can be fun and highly rewarding to think critically about these ideas. What do you know that you know wrong?

Some ideas are better than others. People remember movies, right? Then why not start there? In Star Wars, Han Solo dodges asteroids in the Millennium Falcon to escape Imperial fighters. In Armageddon, the Earth prepares for the impact of an asteroid a thousand miles across. In Deep Impact, a giant comet explodes over the Earth, causing nothing more than a beautiful fireworks display.

If you’ve seen these movies, these are scenes you’ll remember. That makes them a great place to discuss real astronomy, and not the fantasy represented by the movies. You can find out what asteroids really are like; how easy it is to spot a big one and how hard it is to move one; and just why they’re extraordinarily dangerous, even after you blow one up.

My parents may have thought I was wasting my time as a kid watching those bad science fiction movies. It turns out I was simply laying the groundwork for my life’s work.

You can turn Bad Science into Good Science if you start in the right place.

This book is my way of starting in that place. We’ll take a look at a whole lot of bad astronomy. Some of the examples will sound familiar, others likely won’t. But they’re all misconceptions I’ve run across, and they’re all fun to talk about and even more fun to think about.

We’ll uproot those brain weeds and plant healthy greenery yet.

Part I Bad Astronomy Begins at Home

There’s an old joke about a family packing up to move. When their neighbors ask them why they are moving, they reply, “We heard that most fatal accidents happen within ten miles of home, so we’re moving twenty miles away.” Sometimes I wish it were that easy. As a relatively new parent, I hear a lot about how much education my daughter gets at home.

We teach her how to talk, read, do math, socialize, watch TV, argue with us, get her way, be petulant if she doesn’t, and so forth. But often it’s the things we don’t mean to teach that stick. Kids are natural scientists. They watch, absorb information, repeat experiments, and their laboratory is their immediate neighborhood: home, parents, friends, television.

Unsurprisingly, not all the information they gather is accurate.

Astronomy may be the study of everything outside the Earth — that’s not a bad definition — but bad astronomy starts at home.

Why travel to some distant galaxy halfway across the observable universe when you can find examples of errant science right in your own fridge, or even in the bathroom? Science is a way of describing the universe, and the universe surely includes egg cartons and your toilet.

In the next few chapters we’ll see how, like charity, bad astronomy begins in the home. Unfortunately, it doesn’t stay there. You may try standing an egg on its end on the first day of spring at home, but classrooms and television reinforce this experiment as some sort of higher truth. You may not wonder where stuff goes when you flush it down the toilet, but which way that stuff spins as it drains becomes the topic of conversation at water coolers and bars everywhere. Even our very language is sprinkled with bad astronomy, from phrases like “meteoric rise” to “light years ahead.” With luck, though, and a sprinkle of critical thinking, we can plug up the drain of knowledge and topple the egg of ignorance.

1. The Yolk’s on You: Egg Balancing and the Equinox

Consider the humble chicken egg.

Outside, its hard white calcium shell is mostly round and smooth. It might have small bumps on it, or even tiny ridges and waves, but its overall geometry is so well defined that we use the term “egg-shaped” when we see something similarly crafted. The very word “ovoid” comes from the Latin for “egg.” Inside, we have the white part of the egg — the technical term is albumen — and the yellow yolk. This goo is what is destined to become a chicken, if we let it. Usually we don’t. Humans have all sorts of dastardly schemes planned for chicken eggs, from the simple act of cooking them to such bizarre practices as frying them on sidewalks to show how hot it is and using them to “decorate” houses on Halloween night.

But there is an even weirder ritual performed with the ovum of the gallus domesticus. Every year, all across the United States and around the world, this ritual is performed at the beginning