Evidence for ET is mounting daily


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WASHINGTON -- Lately, a handful of new discoveries make it seem more likely that we are not alone — that there is life somewhere else in the universe.

In the past several days, scientists have reported there are three times as many stars as they previously thought. Another group of researchers discovered a microbe can live on arsenic, expanding our understanding of how life can thrive under the harshest environments. And earlier this year, astronomers for the first time said they'd found a potentially habitable planet.

"The evidence is just getting stronger and stronger," said Carl Pilcher, director of NASA's Astrobiology Institute, which studies the origins, evolution and possibilities of life in the universe. "I think anybody looking at this evidence is going to say, 'There's got to be life out there.'"

A caveat: Since much of this research is new, scientists are still debating how solid the conclusions are. Some scientists this week have publicly criticized how NASA's arsenic-using microbe study was conducted, questioning its validity.

Another reason not to get too excited is that the search for life starts small — microscopically small — and then looks to evolution for more. The first signs of life elsewhere are more likely to be closer to slime mold than to ET. It can evolve from there.

Scientists have an equation that calculates the odds of civilized life on another planet. But much of it includes factors that are pure guesswork on less-than-astronomical factors, such as the likelihood of the evolution of intelligence and how long civilizations last. Stripped to its simplistic core — with the requirement for intelligence and civilization removed — the calculations hinge on two basic factors: How many places out there can support life? And how hard is it for life to take root ?

What last week's findings did was both increase the number of potential homes for life and broaden the definition of what life is. That means the probability for alien life is higher than ever before, agree 10 scientists interviewed by The Associated Press.

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  • 2 weeks later...

While the science might be new, the concept of determining the probability of technologically advanced civilizations being within our solar system isn't new. I remembered reading about it in Carl Sagan's The Varieties of Scientific Experience: A Personal View of the Search for God. Sagan introduces the reader to the Drake Equation:

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  • Variables of the Drake Equation
  • N = The number of technical civilizations with the technology to permit interstellar contact (radio astronomy).
  • R = The rate of star formation.
  • fp = The fraction of stars that have planetary systems.
  • np = The number of planets in an average system that are ecologically suitable for the origin of life.
  • fl = The fraction of such worlds in which life actually arises.
  • fi = The fraction of such worlds in which over their lifetime intelligent life evolves.
  • fc = The fraction of such worlds in which the intelligent life develops a technical communicative capability.
  • L = The lifetimes of the technical civilization.

Take note that nobody claims to know these values. Scientists assign informed estimates to these values and these estimates are believed to be fairly accurate. One caveat is that L is the greatest unknown variable in the lot. We have no idea how long the lifespan of a technical civilization is due to the fact that human civilizations is the only technical civilization that we know of and it has yet to end. Carl Sagan demonstrated how this equation worked by assigning values to the equation's variables based on optimistic and pessimistic feelings about the actual variable values. On the optimistic side, the equation delivers an N value of 20,000, meaning that there are potentially 20,000 technical civilizations within the Milky Way galaxy. Of course, if that were true, we may come to the realization that we are still too far from any of them to ever make any attempts to travel to any of those civilizations. Alternatively, pessimism in regards to the actual values of the variables delivers a hard-to-swallow reality that N=1. That states that there is only one technical civilization in the Milky Way galaxy and the unfortunate reality is that the one technical civilization is us.

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