Astrophysicists apply new logic to downplay the probability of extraterrestrial life

Further to our recent post on the Drake equation, we find that a couple of academics from Princetown think it’s a load of bunkum – Deskarati – 

David Spiegel of Princeton University and Edwin Turner from the University of Tokyo have published a paper on arXiv that turns the Drake equation on its head. Instead of assuming that life would naturally evolve if conditions were similar to that found here on Earth, the two use Bayesian reasoning to show that just because we evolved in such conditions, doesn’t mean that the same occurrence would necessarily happen elsewhere; using evidence of our own existence doesn’t show anything they argue, other than that we are here.

The Drake equation, developed in 1960 by Frank Drake uses probability and statistics to derive the possibility of life existing elsewhere in the universe. The data for it comes from observations of the known universe, i.e. the number of stars and solar systems that can be seen, the number that are thought likely to have conditions similar to our own, etc. It’s this equation and its results that drive much of the belief that there surely must be life out there; hopefully, intelligent life.

The problem with all this though, is that so much of it is based on assumptions that have no real basis in reality. As Spiegel and Turner point out, basing our expectations of life existing on other planets, for no better reason that it exists here, is really only proof that were are more than capable of deceiving ourselves into thinking that things are much more likely than they really are.

The two argue that just because intelligent life occurred rather quickly here on Earth, once conditions were ripe, giving rise to the people we are today, that doesn’t mean it naturally would on another planet just like ours in another place in the universe. There are other factors after all, that could have contributed to us being here that we don’t yet understand. So, they contend, deriving numbers from an equation such as that put forth by Drake, only serves to bump up our belief in the existence of other alien life forms, not the actual chances of it being so.

via Astrophysicists apply new logic to downplay the probability of extraterrestrial life.

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2 Responses to Astrophysicists apply new logic to downplay the probability of extraterrestrial life

  1. alfy says:

    I always like to hear a good pair of sceptics. Spiegel and Turner are doing us all a favour. I watched the Drake equation clip. Isn’t he a personable man with such a nice head of dark hair? (Doesn’t mean he is correct though.)

    My first irritation was with the algebra. All he has is a string of coefficients multiplied together. Why not call them, A,B,C, etc? Drake uses all these un-necessary subscripts, A subscript i, B subscript 1 etc, etc. In a popular clip try to keep the math as direct as possible.

    My other criticism was that the figures substituted for the letters seemed a bit too pat. It was not at all clear as to the evidence base for some of them, hence GIGO.

  2. Saburo says:

    “The two argue that just because intelligent life occurred rather quickly here on Earth, once conditions were ripe, giving rise to the people we are today, that doesn’t mean it naturally would on another planet just like ours in another place in the universe. There are other factors after all, that could have contributed to us being here that we don’t yet understand. ”

    Isn’t the very fact that we exist a good enough probability that life could exist in other places as well? Life forms have been found that can survive in extreme conditions, look at tardigrades as an example. They can survive in conditions so extreme that it seems surreal. So, it’s not that doubtful that similar life can’t form on other planets.

    Besides, have we ever been to any planet to confirm? We can see the distant planets, but we can’t see what’s on them, they could have primitive life forms that we’ll never be able to see in most likely hundreds of years.

    It’s a very common fallacy, actually: just because you’ve never seen something, it doesn’t mean it does not exist.

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