Maybe We’re Not Alone. But We’re Probably On Our Own.

Last July I wrote a piece called Maybe We Are Not Alone. The basic idea was that the universe is so large, and there are so many stars and planets, that it seems increasingly difficult to assume Earth is the only place where life ever developed.

Neil deGrasse Tyson’s new book, Take Me to Your Leader,–– does not exactly disagree with that. What it does is make the next question much harder.

Even if intelligent life exists somewhere else, what are the chances that we will ever meet it?

That turns out to be a very different question, and Tyson manages to make the answer both funny and fairly sobering.

The Universe Is a Terrible Neighborhood

Science fiction has trained us to think about space travel as if the universe were a larger version of the Pacific Ocean. Far away, certainly. Difficult to cross, maybe. But eventually somebody builds a better ship.

The real universe is less cooperative.

The distances are absurd. Even the nearest stars are light-years away. Once you move beyond our immediate neighborhood, the numbers become almost meaningless in ordinary human terms.

A civilization could be technologically advanced beyond anything we can imagine and still face a basic problem:

Physics.

Unless somebody discovers a way around the speed of light — and at the moment that remains science fiction — interstellar travel takes enormous amounts of time.

That alone changes the alien discussion considerably.

Existing Is Not the Same as Visiting

This may be the most useful idea in the book. There are really two separate questions: Is there intelligent life elsewhere? And can it get here?

Those are not remotely the same problem.

Life may be common. Intelligent life may even be relatively common. But civilizations may be separated by hundreds, thousands or millions of light-years.

And distance is only part of the problem. Time matters too.

A technological civilization may exist for ten thousand years. Another may appear fifty thousand years later. Both could occupy the same galaxy and never overlap.

So the universe could contain many intelligent civilizations and still produce almost no contact between them.

That is a strange idea.

We may not be alone.

But we may be alone at the same time.

Then There Is the UFO Problem

This is where the book becomes particularly useful.

We have had years of UFO stories, UAP hearings, strange videos, military reports and endless speculation about whether unidentified objects are evidence of extraterrestrial visitors.

Some of those stories are genuinely interesting. Unidentified does not mean imaginary. But it also does not mean alien.

That distinction seems to get lost surprisingly often.

Tyson’s approach is refreshingly simple: before deciding that something crossed interstellar space, perhaps we should first ask whether there is a more ordinary explanation.

That does not make the subject boring. It makes it harder.

And probably more useful.

Take Me to Which Leader?

The title itself points to one of the funnier problems.

Suppose aliens actually did arrive and said, “Take me to your leader.”

Which leader?

The president of the United States? The secretary-general of the United Nations? The leader of China? The pope? The head of some scientific organization? Taylor Swift?

Tyson plays with this problem because it exposes one of the assumptions buried in almost every alien movie. We imagine extraterrestrials arriving and instantly understanding how human civilization is organized.

That seems optimistic.

We barely understand how human civilization is organized.

An alien civilization trying to identify who is “in charge” of Earth might conclude that nobody is.

That would not be an unreasonable interpretation.

Communication May Be Harder Than Travel

Even if we somehow overcome the distance problem, another one appears: communication.

Science fiction usually gives aliens a convenient language translator. Real communication would be much more difficult.

Would they use sound? Light? Mathematics? Chemical signals? Something we have not imagined? Would their sense of time resemble ours? Would they even recognize our signals as communication?

We assume mathematics might provide a common language because physical laws should be universal. That seems plausible.

But going from “we both understand prime numbers” to “please stop vaporizing Cleveland” could still require considerable progress.

The Religion Question

Tyson also touches on how religions might respond to evidence of extraterrestrial life.

That is potentially a very large subject.

I am going to leave it alone.

There are enough arguments available on Earth without importing theological questions from another galaxy.

The Most Interesting Part Is the Timing

The more I thought about the book, the less important the question “Are aliens out there?” seemed.

The harder question is whether two civilizations can exist close enough together, at the same time, and remain technologically capable long enough to discover one another.

Think about our own civilization. Radio signals have been escaping Earth for only a little more than a century. That means our detectable technological footprint has traveled only a tiny distance across the galaxy.

If someone is five hundred light-years away, they cannot yet know that radio exists here. They are seeing Earth as it was five hundred years ago.

And if they send a message back the moment they detect us, we wait another five hundred years for the reply.

That makes conversation rather inconvenient.

Maybe We’re Not Alone

None of this proves that extraterrestrial life does not exist. Quite the opposite.

Given the size of the universe, I still find it difficult to believe Earth represents the only successful experiment in life.

But Tyson’s book reinforces something I did not emphasize enough in my earlier article: existence and contact are completely different things.

There may be life everywhere. There may even be intelligent life in many places. But the distances are enormous, the time scales are enormous, the overlap between civilizations may be tiny, and the physical barriers may be greater than our imagination wants them to be.

So maybe we are not alone.

But for all practical purposes, we are on our own.

That may be less exciting than a flying saucer landing on the White House lawn.

It is probably much closer to reality.

And that may be the most interesting thing about the book.