The Silence of the Universe is Significant

Geoff Marcy, the University of California at Berkeley astronomer who has found scores of exoplanets, and who has diligently searched for signs of anything artificial in the data, says the silence is significant: “If our Milky Way Galaxy were teeming with thousands of advanced civilizations, as depicted in science-fiction books and movies, we would already know about them. They would be sending probes to thousands of nearby stars. They would have a galactic Internet composed of laser beams a...

 Type 0 and Type III Civilizations

It's humbling to realise that the developmental gulf between a miniscule ant colony and our modern human civilisation is only a tiny fraction of the distance between a Type 0 and a Type III civilisation – a factor of 100 billion billion, in fact. Yet we have such a highly regarded view of ourselves, we believe a Type III civilisation would find us irresistible and would rush to make contact with us. The truth is, however, they may be as interested in communicating with humans as we are keen...

 Dyson Spheres

The mathematician Freeman Dyson, of the Institute for Advanced Study, offers a scheme in which the planet Jupiter is broken down piece by piece, transported to the distance of the Earth from the Sun, and reconstructed into a spherical shell – a swarm of individual fragments revolving about the Sun. The advantage of Dyson's proposal is that all of the sunlight now wasted by not falling upon an inhabited planet could then be gainfully employed; and a population greatly in excess of that which...

 Homogenization of the Milky Way

It is possible to speculate on the very distant future of advanced civilizations. We can imagine such societies in excellent harmony with their environments, their biology, and the vagaries of their politics, so that they enjoy extraordinarily long lifetimes. Communications would long have been established with many other such civilizations. The diffusion of knowledge, techniques, and points of view would occur at the velocity of light. In time, the diverse cultures of the Galaxy, involving a...