Messiahs false and true

This infrared image from NASA Spitzer Space Telescope shows the Helix nebula, a cosmic starlet often photographed by amateur astronomers for its vivid colors and eerie resemblance to a giant eye.

Decades ago as a young person, I liked to visit the National Air and Space Museum in Washington, D.C., where one exhibit featured a nine-minute film that played continuously in a loop. I would stand there, in awe, watching it over and over again.

It was called “Powers of Ten: A Film Dealing with the Relative Size of Things in the Universe ...