What does quantum theory and SETI have in common?

And no, I’m not looking for the answer: They’re both expensive branches of science.

Here’s the thing. Everyone’s been looking for a way to unify quantum mechanics with gravity, a so called quantum theory of gravity.

There are numerous theories all trying to explain a way to unify them, often involving reasons why we haven’t found a theory yet. For example, the laboratories at Cern is looking for the Higgs boson. To find it, a new super collider is being built, that can accelerate particles to even higher energies than has been achieved before.
And even while this is being built, some theorist are saying that it won’t be able to achieve the energy level required to detect the Higgs boson.

Each experiment to find a new particle, or examine the structure of space-time in greater detail almost always require more powerful or more sensitive experiments. And sometimes it’s not even necessary. A twin satellite system called Gravity Probe B was launched recently to detect the distortion of space-time that occurs near a large, rotating body (like the Earth). And yet, the data to prove their case already existed from the Mars Global Surveyor in polar orbit around Mars.

This is exactly the same argument that has been levied at SETI. The argument goes something like this:

If we spend the next 100 years searching with every radio telescope on Earth, looking for signals from intelligent aliens, we still might not find anything. And yet, there’s always another way to search, different fequencies, different methods, another reason we haven’t found the alien signal, another reason to change the way we’re searching.

Since we don’t know in advance if there are intelligent signals to detect, we can’t be sure that it’s worth searching at all. Compare that with clearing a minefield, for example. You can be certain there are mines there, and you can be certain that you’ve got them all after you’re done.

The search for a unified theory might have the same problem. There’s no proof that such a unification is even possible. In fact, the reason we’re searching in the first place is that we know that both theories are correct (they’ve been obsevered working), except that they contradict each other.

So we have a choice:

• Continue searching for a way to unify the two branches of science or,
• Learn to live with the contradiction.

It’s something of a conundrum for humans. We can’t resist a good mystery.

And so, we search.