Solution Life Can Have Emerged Only Recently

To everything there is a season, and a time to every purpose under heaven. The astronomer Mario Livio takes issue with the notion that the timescale for the evolution of intelligent life is completely independent of the main sequence lifetime of a star. if the two timescales were related in a particular way if the evolutionary timescale increases as a star's lifetime increases then we would expect to observe the two timescales as roughly equal. Carter's gloomy conclusion about the non-existence...

Solution Jupiters Are Rare

What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent Richard Philips Feynman, The Feynman Lectures on Physics Since the first discovery in 1995 of extrasolar planets, or exoplanets, astronomers have found 60+ more planets beyond our Solar System. Many of these are Jupiter-sized objects orbiting in nearly circular orbits close to the parent star. (Consider the planet orbiting Rho CrB, for example. Of all...

Solution They Have No Desire to Communicate

Speech is great but silence is greater. Thomas Carlyle, Essays Characteristics of Shakespeare So far we have assumed that ETCs want to communicate. Maybe they don't Resolutions of the paradox based on the idea that ETCs will keep themselves to themselves depend on making assumptions about the motives of alien beings. If such beings exist, they will be the product of billions of years of evolution in unearthly environments, with senses, drives and emotions different from our own. Or they may be...

Solution They Are Somewhere But the Universe Is Stranger Than We Imagine

Listen there's a hell of a good universe next door let's go. e. e. cummings, pity this busy monster, manunkind The theories of modern physics are remarkable in their range of applicability. They explain phenomena at scales as small as the electron and as large as super-clusters of galaxies. They explain events that happened a tiny fraction of a second after the Big Bang, and we can use them to determine the fate of the universe. Some might say physicists are arrogant, filled with hubris for...

What Is Intelligence

In terms of SETI activities, we can reasonably define a species as intelligent if it can build a radio telescope. The problem with this definition is that mankind apparently became intelligent only about 50 years ago So although in a practical sense it might be a good definition, it fails on philosophical grounds. There must be a better way of capturing the essence of intelligence. A common approach is to define intelligence in terms of certain mental tasks that we find difficult, such as...

Solution Berserkers

During the 1950s, Cold War strategists toyed with the idea of a Doomsday weapon. Such a weapon was terrible, uncontrollable, capable of destroying all human life on Earth including the owners of the weapon. If your enemy knew you were willing to deploy a Doomsday device then so the Cold War logic went they would not dare attack you. I suspect that Fred Saberhagen had the Doomsday weapon in mind when he wrote his famous berserker stories.138 Berserkers are sentient, self-reproducing machines...

Solution Earths System of Plate Tectonics Is Unique

What we want is a story that starts with an earthquake and builds to a climax. Our planet has been destructive in recent years. Earthquakes in Turkey and India have caused huge loss of life smaller quakes in America and Japan have caused inconvenience and as I write, Mount Etna is spewing forth lava that threatens the livelihood of several hundred villagers.208 It therefore seems strange that some geologists consider the existence of plate tectonics the process that gives rise to earthquakes...

Solution The Planetarium Hypothesis

Stephen Baxter has proposed an interesting variant on the zoo scenario. He calls it the planetarium hypothesis.64 The speculation is far wilder than Ball's idea, but it merits the term hypothesis rather than scenario because it offers testable predictions. Is it possible, Baxter asks, that the world we live in is a simulation a virtual-reality planetarium engineered to present us with the illusion that the Universe is devoid of intelligent life The physics behind such an idea has a modern feel...