Life in the Universe

Lead: Tavus Begenjova & Ed Bourbeau

4/11/2005

Summary by Kellee Duckworth:

Readings:
"God for the 21st Century" Part 4, by Russell Stannard ed.

“'Fifty Planets’ Could Have Life”, by Helen Briggs

Ed started this topic with three simple facts:

          • There are trillions of stars in the universe.
          • Many of the stars are too hot to support life.
          • Malcolm Jeeves suggests that the body, mind, and the soul are all one package and should not be thought of as separate entities.
          • Many of the planets that have been found are too large and thus too cold to support life.

What made life of earth possible was its perfect placement in the solar system and the possession of a moon.

Ed then led us further into the topic with mentions of recent findings which could lead to the discovery of life on Mars. If life were found it would further the discussion of the questions…Is there other life out here? Is there intelligent life out there? These questions are not new and have been debated for some time. Scientists fall into three main categories when discussing this topic; life isn’t likely, life is likely but not intelligent life, and intelligent life is likely.

In an attempt to answer the questions of whether life and intelligent life are possible in the universe, Frank Drake developed an equation in 1961 named after him. This equation, listed below, solves for a value of N which is the number of detectable civilizations in our galaxy.

N = R * fp * ne * fl * fi * fc * L

R = rate of star formation within the galaxy expressed in stars/year
fp = fraction of stars that form planets
ne = average # of planets each star possesses capable of supporting life
fl = fraction of those planets where life actually occurs
fi = fraction of life-bearing planets where intelligence arises
fc = fraction of life-bearing planets where intelligent beings develop the ability to communicate beyond their own world.
L = length of time (in years) that such communications remain detectable

An in depth look at the findings and theories behind the values sheds more light on the equation.

R: In 1961 it was estimated that the value of R=1. In 2005 that number has increased to 10-20/year. Some of these stars are small and many lack the heat output to support life-bearing planets.

fp: Estimates show that 20%-50% of all stars have planets. Proof for this estimate has been shown through star shift observations.
ne: Of the number of stars that have planets that orbit a star, 1 out ofto 5 is are thought to be capable of supporting life. As life requires liquid water, a planet would need to be located in the “goldilocks” zone for conditions to be just right. The planet Mars and the moons Europa and Titan are being looked at as possible candidates for primitive life in our solar system. While they are outside the “goldilocks” zone, they have all at one time held liquid water on their surfaces. If this is still the case, all three may contain life.

fl: Current estimates of the percentage of planets that are capable of supporting that actually become life bearing ranges from 100%, that is all planets, to close to 0%, that is very few planets.

fi: Of the planets capable of bearing life, it is estimated that less than 1% of those will contain intelligent life. While intelligence is believed to be an end point of evolution, many events could take place to slow the evolution of life or end the life on the planet all together. As it has taken 4.5 billion years to intelligence to evolve on earth, it can be assumed it would take a long time on other planets as well.

fc: Of the planets that contain intelligence, it is believed 10-20% would be able to communicate with others off their planet. The lack of signals does not show a lack of intelligence, only a possible lack of technology to communicate..

L: The length of time the communication would remain detectable is not indefinite. The signal would eventually become undetectable as it spread out through space, and the civilization may disappear after some time.

Pessimistic values for N are 7 detectable civilizations in our galaxy while optimistic values are as high as 10,000.

Tavus then took over and led the discussion into the realm of religion and social issues surrounding life on other planets. Many early cultures showed their gods and goddesses as celestial beings coming from space. These depictions are similar in many different societies across the globe.

The development and use of tools for off world communication requires a certain anatomical shape. While dolphins are highly intelligent, they lack the required anatomy to build and use tools. They are not likely to be communicating with beings from another world.

Communication not only requires the use of tools but the tools themselves. This requires an evolution of society from stone tools to metal tools to electronics. A possible way around this evolution was proposed by using carbon as a semi-conductor for communication. Tools made in such a way could make the beings more advanced than us but it is unlikely that evolution would have taken that turn.

How would we communicate? The leading theory is through math encryption similar to the methods used in the movie and book Contact. Prime numbers are likely to be a universal mathematical fact so they would be a way to encode a message knowing that someone would detect the pattern from the background radio noise.

Could life come in different forms? Some people believe that silicon based life forms could evolve since silicon is very similar to carbon in its molecular bonds. This theory has not been well accepted as the higher electron number of silicon makes it more likely to react than carbon.

Many other questions remain:

• Would finding new civilizations change our perception of ourselves? Would we feel superior or inferior to the civilizations?
• What would we do if we found them? Would things end as they did during the European Colonization?
• Could the limits of physics force us to stay home? Is it were we should stay anyway? Is it a good thing that we stay home?