New Analysis: We Are Alone in the Universe

Astrophysicist David Spiegel and physicist Edwin Turner say that the life here on Earth could be common, or it could be extremely rare—there's no reason to prefer one conclusion over the other. 

What's the Latest Development?


Astrophysicist David Spiegel at Princeton University and physicist Edwin Turner at the University of Tokyo argue, using a statistical method called Bayesian reasoning, that life here on Earth could be common, or it could be extremely rare—there's no reason to prefer one conclusion over the other. "It took at least 3.5 billion years for intelligent life to evolve on Earth, and the only reason we're able to contemplate the likelihood of life today is that its evolution happened to get started early. This requisite good luck is entirely independent of the actual probability of life emerging on a habitable planet."

What's the Big Idea?

While Spiegel and Turner's analysis doesn't disprove the existence of alien life, it does argue that we have no good reason to think there is life beyond our own planet. The likelihood of another planet producing life is independent of the success of ours, say the physicists. "'Although life began on this planet fairly soon after the Earth became habitable, this fact is consistent with ... life being arbitrarily rare in the Universe,' the authors state. In the paper, they prove this statement mathematically."

Related Articles

A controversial theory claims past, present, and future exist at the same time

Our experience of time may be blinding us to its true nature, say scientists.

Back to the Future.
Surprising Science
  • Time may not be passing at all, says the Block Universe Theory.
  • Time travel may be possible.
  • Your perception of time is likely relative to you and limited.
Keep reading Show less

Six disastrous encounters with the world’s most hostile uncontacted tribe

From questionable shipwrecks to outright attacks, they clearly don't want to be bothered.

Culture & Religion
  • Many have tried to contact the Sentinelese, to write about them, or otherwise.
  • But the inhabitants of the 23 square mile island in the Bay of Bengal don't want anything to do with the outside world.
  • Their numbers are unknown, but either 40 or 500 remain.
Keep reading Show less

Found: second draft of Galileo's argument for a heliocentric model

At least he wasn't burned at the stake, right?

The original letter in which Galileo argued against the doctrine of the Roman Catholic Church has been rediscovered in London. Image credit: The Royal Society
Surprising Science
  • The letter suggests Galileo censored himself a bit in order to fly more under the radar. It didn't work, though.
  • The Royal Society Journal will publish the variants of the letters shortly, and scholars will begin to analyze the results.
  • The letter was in obscurity for hundreds of years in Royal Society Library in London.
Keep reading Show less