Rizzo wasn't discouraged. "Listen, the chances—just on statistical figuring alone—the chances are that there're millions of other solar systems with intelligent life. We've got to try contacting them! They might have knowledge that we don't have ... answers to questions that we can't solve yet...."
"I completely agree," I said. "But listening for radio signals is the wrong way to do it."
"Huh?"
"Radio broadcasting requires too much power to cover interstellar distances efficiently. We should be looking for signals, not listening for them."
"Looking?"
"Lasers," I said, pointing to the low-key lights over the consoles. "Optical lasers. Super-lamps shining out in the darkness of the void. Pump in a modest amount of electrical power, excite a few trillion atoms, and out comes a coherent, pencil-thin beam of light that can be seen for millions of miles."
"Millions of miles aren't lightyears," Rizzo muttered.
"We're rapidly approaching the point where we'll have lasers capable of lightyear ranges. I'm sure that some intelligent race somewhere in this galaxy has achieved the necessary technology to signal from star to star—by light beams."
"Then how come we haven't seen any?" Rizzo demanded.
"Perhaps we already have."