SciencePunk has a nice post on “Five iconic science images, and why they’re wrong.” The visual clichés in question include the Atom With Hula Hoops, the Monkey Turning Into a Guy with a Spear, and the Pocket-Sized Solar System.
The last of these reminded me of a passage in Bill Bryson’s A Short History of Nearly Everything, one of the best popular science books ever:
Most schoolroom charts show the planets coming one after the other at neighborly intervals—the outer giants actually cast shadows over each other in many illustrations—but this is a necessary deceit to get them all on the same piece of paper. Neptune in reality isn’t just a little bit beyond Jupiter, it’s way beyond Jupiter—five times farther from Jupiter than Jupiter is from us, so far out that it receives only 3 percent as much sunlight as Jupiter.
Such are the distances, in fact, that it isn’t possible, in any practical terms, to draw the solar system to scale. Even if you added lots of fold-out pages to your textbooks or used a really long sheet of poster paper, you wouldn’t come close. On a diagram of the solar system to scale, with Earth reduced to about the diameter of a pea, Jupiter would be over a thousand feet away and Pluto would be a mile and a half distant (and about the size of a bacterium, so you wouldn’t be able to see it anyway).
You can see why it’s never drawn to scale: the web page is apparently about half a mile wide, on a typical computer screen. Happy scrolling.