We talked about the Fermi Paradox: “Where are they?” Enrico Fermi at Los Alamos in 1950 posed the question over lunch, reasoning that aliens should have long ago showed up to visit if, in fact, they are out there. The UFO mythology is unpersuasive, leaving us with this cosmic mystery. Maybe they are just not there. Shostak is among those who thinks that they are surely there and that we just need to keep listening. SETI, named for the search for extraterrestrial intelligence, goes back to 1960, when Frank Drake turned a radio telescope at Green Bank, W.Va., toward two nearby sun-like stars. What we heard then, and have heard ever since, is what Paul Davies calls the “eerie silence.” Shostak remains confident we’ll succeed eventually in detecting the presence of ETI. Eight years ago, in a speech, he bet a cup of Starbucks coffee for everyone in the room that it would happen within 25 years.

In our conversation, he reiterated that the silence so far reflects only the feebleness of our detection capabilities. We’d have a hard time, for example, picking up television leakage from the nearest star, never mind the ones on the far side of our galaxy or in other galaxies. The only civilizations we can readily detect are ones relatively nearby in the cosmic scheme of things and which are intentionally sending signals our way.

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Speaking of those other galaxies: The universe is not really designed for communication. It’s too big. The stars are too far apart for large, meat-based creatures to travel around easily. We can’t even exchange messages without a significant time delay. You run into the Einstein speed limit. Information can’t move faster than the speed of light. If there are aliens on Proxima b, the nearest planet beyond our solar system, we would have an eight-year [I originally wrote “eight-minute," which of course is more like communication with Mars!] time lag between our initial message of “How’s it goin’?” and the alien response of “Fine.”

I’m not complaining about the size of the universe. That would be kind of futile. That’s an issue way above my pay grade. As Lawrence Krauss puts it: The universe is what it is.

But golly, it’s ridiculously large. Space strikes me as ostentatiously spacious. If you count the galaxies in the observable universe you wind up with Saganesque numbers.

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Annoyingly, we can’t communicate with civilizations in these other galaxies unless, as Shostak put it, their conception of time is different from ours. It’s hard to have a meaningful conversation with a time lag of millions of years.

One wonders if there could be such a thing as a “small, compact, conveniently laid-out universe.” Someone please run those inflation numbers through the computer a few more times and see if you can get a mini-cosmos.

Or maybe the bigness of the universe has an anthropic-principle implication. Just thinking out loud here: An intelligent observer should potentially expect to find herself in a universe of grand dimensions, because such a universe has abundant terrain for the evolution of intelligent observers.

And maybe the extreme spaciousness has protective factors. Isolated worlds are safe from contamination and invasive species.

Yeah, for now we’re alone in a great big universe — but maybe that’s not so bad.