When it comes to physically exploring deep space, pretty much the slowest thing you could ever really do is send a towering hunk of metal weighing about a hundred tonnes into the sky above, thanks to a burning mass of rocket fuel – and yet, that's effectively where today's crewed space travel is at.

But one of the most mind-boggling proposals we've seen to get around these kinds of limitations is the prospect of sending postage stamp-sized spacecraft into space at extremely high speeds via laser propulsion.

And now, one of the researchers behind that project says the same photonics technology could not only transform space exploration as we know it – it could also overhaul the search for extra-terrestrial intelligence.

The idea is that advanced life forms – if they're actually out there and want to be found – could be using the exact same kind of 'directed energy' systems to be broadcasting their presence to us.

Physicist Philip Lubin from the University of California, Santa Barbara, says the type of laser propulsion system backed by Stephen Hawking to send a 'nanocraft' to Alpha Centauri in 20 years could enable us to pick up alien transmissions from anywhere in the Milky Way – and even beyond.

"If even one other civilisation existed in our galaxy and had a similar or more advanced level of directed-energy technology, we could detect 'them' anywhere in our galaxy with a very modest detection approach," said Lubin. "If we scale it up as we're doing with direct energy systems, how far could we detect a civilisation equivalent to ours? The answer becomes that the entire Universe is now open to us."

To read more, click here.