“[M]aterials [to reproduce the von Neumann machine] should be available in virtually any stellar system—including systems—in the form of meteors, asteroids, comets, and other debris from the formation of the stellar system. ...[M]aterial in asteroids are highly differentiatied; many... are largely nickel-iron, while others contain large amounts of hydrocarbons.”
Frank J. Tipler
More by Frank J. Tipler

“It is argued that if extraterrestrial intelligent beings exist, then their spaceships must already be present in our solar system.”

Frank J. Tipler

“[A]n intelligent species with the technology for interstellar communication would necessarily develop the technology for interstellar travel, and this would automatically lead to the exploration and/o...”

Frank J. Tipler

“[T]hat any intelligent species which develops... interstellar communication will also have... rocketry... is... a consequence of the principle of mediocrity... (that our own evolution is typical)... [...”

Frank J. Tipler

“[I]t seems likely that a species engaging in interstellar communication would possess a fairly sophisticated computer technology. ...Sagan has asserted that 'Communication with extraterrestrial intell...”

Frank J. Tipler

“I shall assume that such a species will... develop a self-replicating universal constructor with intelligence comparable to the human level—such a machine should be developed within a century, accordi...”

Frank J. Tipler