Answer, please answer

by Ben Bova

"What?"

"We've observed all sorts of variable stars—Cepheids, RR Lyrae's, T Tauri's. We assume that what we see are stars, pulsating and changing brightness for reasons that are natural, but unexplainable to us. Now, suppose what we are really viewing are laser beams, signalling from planets that circle stars too faint to be seen from Earth?"

In spite of himself, Rizzo looked intrigued.

"It would be fairly simple to examine the spectra of such light sources and determine whether they're natural stars or artificial laser beams."

"Have you tried it?"

I nodded.

"And?"

I hesitated long enough to make him hold his breath, waiting for my answer. "No soap. Every variable star I've examined is a real star."

He let out his breath in a long, disgusted puff. "Ahhh, you were kidding all along. I thought so."

"Yes," I said. "I suppose I was."