Astronomers have used all sorts of tricks over the years to try to convey the mind-boggling scale of the universe to us ordinary folks. If you could drive your car from here to the nearest star at 60 m.p.h., they've told us, it would take 11 million years. If the sun were a beach ball sitting on a football field's goal line, Earth would be a pea on the 50-yard line. And so on.
Things got a little more sophisticated with the extraordinary 1968 film Powers of Ten, which zooms out from a bucolic scene in a Chicago park to encompass ever wider panoramas until it captures an artist's rendering of the entire visible universe, then zooms back down into the hand of a sunbather lying on the grass, probing the ever tinier world of the microscopic, atomic and subatomic.
But now comes the latest attempt to put the cosmos in perspective, and it may be the most effective yet even though it takes the retro form of a physical book. Most coffee-table astronomy books are simply collections of gorgeous images, and Sizing Up the Universe (National Geographic; 248 pages) is certainly that. But it's more too: it also conveys the relative sizes and distances of cosmic objects in so many different and ingenious ways that it becomes a little dizzying in the best possible sense.
In the first chapter, for example, titled "The Shape of the Sky," co-authors J. Richard Gott and Robert Vanderbei, two Princeton University professors, show how large celestial objects actually look to us or would, if some of them weren't too faint to see. Because the moon is so close, it appears relatively huge in the sky, while the giant star Antares, many times bigger than our sun but hundreds of light-years away, looks to us like a pinpoint. Gott and Vanderbei put the two side by side on a page to show that the way our eyes see things, you could place Antares on the surface of the moon and it would barely cover the Apollo 11 landing site which itself was smaller than a baseball field. One page later, they use the moon again to show that if you put the silhouette of the nearest star, Proxima Centauri (much smaller but much closer than Antares), on our satellite's surface, it would cover not the entire landing site but just Buzz Aldrin's footprint.
In another section, the authors compare the actual sizes of planetary features Lake Michigan vs. the hydrocarbon lakes on Saturn's moon Titan, with real images at comparable scales (Lake Michigan is a lot bigger); or the giant Olympus Mons volcano on Mars set against the comparatively puny Mauna Kea, in Hawaii; or Hurricane Katrina against Jupiter's Great Red Spot in that contest, the mighty Katrina looks positively puny or the embarrassingly minuscule Grand Canyon superimposed on Mars' gaping Valles Marinaris. And then, just for the heck of it, they throw in side-by-side images of a sunset on Earth and a sunset on Mars. No particular science lesson there; it's just exceedingly cool.
The genius of Sizing Up the Universe comes directly from the co-authors' fertile brains. Gott is an eminent astrophysicist, an expert on general relativity who wrote the popular book Time Travel in Einstein's Universe in 2001. He's long been fascinated with trying to visualize cosmic concepts so much so that he created a richly illustrated timeline of the universe, from modern Earth all the way back to the Big Bang, on a logarithmic scale that allows the whole thing to fit into the fold-out centerpiece of the book. His Princeton colleagues were impressed enough to have it woven into carpeting that runs down the hallway of the astronomy department.
"Rich," one of them once said, with deep admiration, "is perhaps the most genuinely eccentric person I know."
Vanderbei, meanwhile, comes from the esoteric computer-science discipline known as operations research; he got into astronomy the old-fashioned way, as an amateur. They both have an equally powerful passion, though, for trying to bring the cosmos to the masses preferably in ways nobody else has thought of. "My interest in astronomy started when I was 8," says Gott, "and I think of all the objects we couldn't have put in this book at that time because we didn't know they existed black holes, neutron stars, quasars, extrasolar planets and more. It really strikes me how far we've come."
It may strike readers, meanwhile, that the authors must have conjured up some sort of Einsteinian space warp to get so much information, in such a variety of vivid, gorgeous and conceptually brilliant forms, into a single book. You can pretty much open it to any page and have an "aha!" moment that will embed itself in your brain.
And over time, without even noticing, you may even begin to grasp the true immensity of the universe.