They’ve got your number (Image: Andrzej Krauze)

STEPHEN HAWKING is worried about aliens. The famous physicist recently suggested that we should be wary of contact with extraterrestrials, citing what happened to Native Americans when Europeans landed on their shores. Since any species that could visit us would be far beyond our own technological level, meeting them could be bad news.

Hawking was extrapolating the possible consequences of my day job: a small but durable exercise known as SETI, the Search for Extraterrestrial Intelligence.

Although we have yet to detect an alien ping, improvements in technology have encouraged us to think …