but when I formally studied astronomy, the Big Bang wasn't yet agreed upon by all astronomers, and some older textbooks still claimed the solar system was a freak caused by a "just right" tidal encounter with another star. People were still hoping there were fields of vegetation on Mars and that Venus was a jungle planet, a water world, or alternatively, covered with an ocean of petroleum.

Since then, I've done little to keep up with astrophysics and cosmology other than read Sky and Telescope, and I let my subscription expire a couple of years ago.

The only specialty I've stayed pretty current with is positional astronomy (because of my interest in navigation and cartography). I studied that under two of the acknowledged masters in the field, George Gatewood and Heinrich Eichorn.

The field is changing fast as it is impacted by all this new data coming in from the space program, and it is pretty much in disarray. But that's a good thing. A very good thing.

One advantage of being old is you develop a feeling for how things are progressing in a rapidly evolving field. We know a great deal more now than we did in the 60s, but we're a lot less sure we know what it all means than we were then. Its a cliche, but it is also undeniable, the more you learn, the more you realize how little you know.

The swamp looks very different when you're deep inside it than it did when you walked up to the edge of it.