The Dipper is of the few constellations that actually looks like its name. This raises a question that you’ve probably asked yourself: What were our ancient ancestors thinking when they connected the stars into constellations? Many constellations do not even remotely resemble their names. So, what were our ancestors thinking—or smoking?
I’ve been teaching astronomy since 1980, so I’ve spent a lot of time trying to justify the constellations’ names to people. Finally, I got so tired of being in this awkward position, that I did something about it. I put my feet into the shoes of our ancient, sky-watching ancestors. And I hope you’ll join me there, back in the days before electricity, cars, planes, oil tankers and supermarkets.
Or maybe you and I should put ourselves in the future, after the time when oil spills have made it impossible to ship our food halfway around the planet. So, we are growing, gathering and hunting our protein. And it isn’t available 24/7 and it isn’t available 365 days of the year. It grows only in certain seasons. It migrates through our territory only in certain seasons. It flies over our territory only in certain seasons. It swims close enough to be caught only in certain seasons. If we don’t know its natural rhythms, we don’t get to pass on our genes to future generations.
The particular stars we see tonight are the same stars we saw on this date every year in the past and they are same stars we will see on this date every year in the future.
Fortunately for you and me, our ancestors passed on their genes. They tracked the annual life cycles of plants and animals and they devised ways to make the most of these cyclical opportunities. During the seasons when they didn’t need their garden tools or their fishing or hunting gear, they repaired and upgraded this equipment.
They also kept their eye on the sky. They saw that the visibility of certain stars is how we can know what time of year it is. (The visibility of certain stars is how we can know where we are in our yearly orbit.) The particular stars we see tonight are the same stars we saw on this date every year in the past and they are same stars we will see on this date every year in the future.
Yes, the sky was our ancestors’ calendar, and it was the only calendar on Earth for 99.99 percent of human existence. If you want to use the sky as a calendar, you have to divide it into sections. Everybody using this calendar has to agree on what to call the sections. Some sections look like their names, and some don’t. But so long as everybody agrees on the names, everybody can use the calendar; and everybody can eat protein.
Last night as I gazed at the Big Dipper, I made a wish on its stars.
My wish is that your next meal will be more tasty and more nutritious, because while you'’re eating it, you’re thanking our ancient ancestors for figuring out how to pass on their genes to you by inventing constellations.