Astronomy
The Search for Technosignatures in the Optical and Infrared Spectrum
Quick fact
The first optical SETI search, conducted in 1998, looked for nanosecond laser pulses from nearby stars, and though no signal was found, it opened a new frontier: using starlight itself as a communication medium, potentially thousands of times more efficient than radio.
Why this is interesting
When we think of alien signals, we usually imagine crackling radio static. But what if the most obvious sign of an advanced civilization is a brief flash of laser light or a planet glowing with wasted heat?