Possibilities, hundreds of thousands of possibilities! To read and enjoy Life in the Universe: the Abundance of Extraterrestrial Civilizations, one must be prepared to deal in the realm of probability and possibility to an enormous degree. So often the media almost reports as fact, the alleged encounter someone had with an alien-appearing object either in space or on the ground. Movie makers with their bag of computerized tricks have produced films which are extremely convincing. These herald as truth the idea that distant space travel is somehow possible — alien beings exist not only in our own galaxy but in uncountable others — some have visited our earth.
Life in the Universe attempts to show in a logical and realistic fashion what conditions must be necessary for life — as we know it — to exist elsewhere in our galaxy. After a brief explanation of the scientific method, probability and possibility, Pierce’s book describes science’s present understanding of atoms and molecules, and the basic interaction of their chemistry to produce life. If life is to be found on distant planets, then the critical environmental attributes needed to sustain life must be present in those remote places.
Pierce then reviews what those characteristics are, here on our home planet. He describes how interrelating the dating of rocks and fossils has helped science date the origin of life on planet earth. This is necessary to pinpoint rather accurately how long it took the first primitive living creatures to adaptively evolve into thinking man. Knowing this can help science estimate how long it would take intelligent life to develop on other planets once they estimate when those planets came into existence. Obviously, only a technical civilization would be advanced enough to engineer extra terrestrial contact.
Near the middle of Life in the Universe: the Abundance of Extraterrestrial Civilizations, Pierce introduces the Drake Equation, a formula which has been accepted by science as a means of estimating civilizations within our own galaxy. The equation at first looks mean and frightening, but Pierce provides an explanation for each term that any layman could understand, along with an equally simple rationale for the possible value of each term.
N = N. • fs • Np • Fe • Fl • Fi • Fc • L ÷ t
N = number of technical civilizations possibly existing in our Milky WayGalaxy (what we are seeking).
N. = number of stars in the Milky Way = 200 – 400 billion
fs = fraction of stars sufficiently Sun-like to support a civilization = .11 – .25
Np = average number of planets per Sun-like star = 1 – 20
Fe = fraction of Earth-like planets capable of supporting life = .033 – .11
Fl = fraction of Earth-like planets on which life might develop = 0 – 1
Fi = fraction of life-bearing planets that evolve intelligent beings = 0 – 1
Fc = the number of life-bearing planets where intelligent beings develop a technical civilization = .01 – .05
L = the average lifetime of a technical civilization = 500 years – 100,000 years
t = Average time from the formation of the Milky Way before a technical civilization arose (3 billion years)
To prove to myself that solving the formula was not hard, this reviewer selected a middle value for each of the above terms except for L (the average lifetime of a technical civilization). For that term I picked 3000 years because it seemed like a more realistic time span due to present global climate changes and our race's propensity for nuclear warfare. Science continually warns us about irreversible catastrophic damage to our planet, and I believe those warnings are real. Here is my equation filled in:
N = (200,000,000,000)(.18)(10)(.08)(.5)(.5)(.3)(3000) ÷ t (3,000,000,000) = 2,133
Thus, there is the possibility that 2,133 technical civilizations currently exist within the Milky Way. One must be mentally bamboozled when thinking of multiplying this number by the billions of similar galaxies in the entire universe.
The remainder of Life in the Universe deals with the impossibility of space travel even to the closest planets outside of our solar system but still within the Milky Way Galaxy. The distances we’d have to travel, even if speed-of-light travel was possible, are unfathomable.
Pierce spends some time explaining how signals from outer space are collected and interpreted. A variety of methods are used to examine incoming signals to see if there is any decipherable message in them. In all probability, the binary number system would be used because it is the easiest to interpret. An alien only need to recognize that any given bit of information can have only one of two values. Thus, language would not be a problem. The binary system can easily transpose an off or on signal into a pictogram as shown here.
Life in the Universe: the Abundance of Extraterrestrial Civilizations is a fascinating study into the realm of possibility. Based in earth’s reality and our solar system, the book attempts to blast us out along the Milky Way searching for intelligent alien life, even though we have no realistic mode of interstellar travel and probably never will.
If you are interested in the size of the universe and our humble place in it, this book is a must for you. As I’ve shown above, its math concepts require no advanced math degree. As long as you can multiply and divide, you too can crunch your own numbers and then ponder: Are we alone in the universe? I would be interested in your comments about the book and my review. They can be left below where it says: Add Your comments; Speak Your Mind.