Words on worlds

“I’ve been around the world,” some wit said, “and it hates each other.” That’s a good chunk of world history summed up in one brief sentence, so what more can be said about worldly concerns?
Well, here’s something we can say: There are a whole lot of other worlds out there. So if you get tired of thinking about ours, you can direct your attention to a growing list of interesting alternatives.

In fact, the tally of “exoplanets” detected, which are planets outside of our solar system, is in the thousands now. The count exceeds 1,700 but the list of good prospects is around 3,000 and this is sure to grow.

For sake of perspective, I’ll note that when I was in college the tally of exoplanets was a big fat zero.

Back then, if you told me that I’d live to see the day when astronomy magazines would in matter-of-fact terms mention some of the latest exoplanets discovered, much like the financial press reports the latest bank merger, I would have dismissed the notion as science fiction. After all, even the nearest star (not including the sun, of course) is about 25 trillion miles away. To my mind, finding planets that far away seemed like an impossible idea.

Of course, the notion of exoplanets isn’t all that new. The theories about how stars and their accompanying solar systems form were plainly spelled out in school texts. The ideas were right, at least insofar that they assumed that many other stars had planets, but the observations to prove that those planets existed had not yet taken off.

Well, that sure changed. Technology has zoomed ahead.

As far as the observations go, only a handful of exoplanets have been directly observed. The vast majority are detected by clever analysis of precision measurements, such as noting how a star gets dimmer and brighter on a regular basis. This can happen for a number of reasons, but one reason is that the star is being “eclipsed” by an orbiting planet. In this case, when the planet is transiting in front of the star (from our observer’s perspective), the star appears a little bit dimmer because the planet is blocking some of its light, and then when the planet is in back of the star and not in the way anymore, the star appears a little bit brighter.

Well, that’s pretty freaky science, measuring things in such teeny-tiny detail. But freakier still is that entire systems of exoplanets are being discovered.

In fact, to me, the “how” is more interesting than the “what.” I like hearing about how the astronomers and physicists figure this stuff out.

As for the “what,” which is to say, the exact composition and nature of the various exoplanets, well, that’s fueling an increasingly large body of news these days.

As you might imagine, one lively topic in the exoplanet realm concerns how many of these planets are candidates to harbor life. It’s a bit of a Goldilocks game where, for example, the planet should be not too hot, or not too cold, but just right. I don’t really follow this end of the gig, though, so if some remote colony of space creatures ever sends us a selfie I’ll be the last to know.

But there is a standing vigil for such things, at least to the extent that selfies can come via radio waves. For example, the search for extraterrestrial intelligence (SETI) program keeps an analytical watch on various frequencies in hopes of detecting the electronic emissions of cosmic creatures.

I’ll emit a couple of intriguing things that I like to ponder.

Last year, an exoplanet expert told me he estimates that, on average, there’s about one planet for every star out there. That’s a very rough estimate, of course, but even if it’s off by a factor of 10 in either direction it provides some perspective. I’m sure that in a few years more refined estimates will come our way. But for now, I’ll just take this at face value.

A second notion in general circulation runs like so: It’s said that the universe has more stars than the planet Earth has grains of sand in all of its beaches and all of its deserts. No, I have not audited the math, but even if it’s nearly true it’s mighty interesting.

If we want to just dovetail the two notions in a neat, one-for-one substitution, we could guesstimate that every earthly grain of sand represents another planet in the universe. That’s food for thought the next time you’re walking down Saipan’s Micro Beach, eh? How many worlds are stuck to the bottom of your zoris?

Of course, the only world you really have to deal with is the biggest one stuck to the bottom of your zoris: this world, and all that goes with it, including the fact that Earthlings sure do seem to hate each other sometimes. Welcome home!

Visit Ed Stephens Jr. at EdStephensJr.com. His column runs every Friday.