February General Meeting
Dr Allie Ford, School of Mathematical Sciences Monash University
Life in the Universe
The question of life, what it is (how to define it), where it comes from (or how it came about) has become very important to us over the last two hundred years. Ever since science detached itself from religion (superstition) the loss of ordained creation and doubts about a benevolent beginning left in us a deep void struggling to be filled: Who are we? For some innate reason we humans have a need to know our parents, our family tree, our importance; it seems to give us “legitimacy” in society and a meaning to our lives. Could life be just an accident? Are we humans a freak of nature? Are we alone in the Universe? Or is there a natural progression, an evolution where, if the conditions are right, life will (in stages) self-assemble itself in all its endless varieties, everywhere. Is what we call “Life” just another stage in the universal balancing act between matter and energy? (see What is Life)
Life in Dr Allie Ford’s talk centred on the conundrums of the Drake equation: The likelihood of seven “Ifs” multiplied together, none of the quotients being better than 50% accurate, providing a sensible answer to the question of its proliferation (see Drake Equation). The Drake equation (sometimes called the "Green Bank Formula") is an attempt to build on the question “where are they?” first raised by Enrico Fermi 60 years ago, and to calculate the potential number of extraterrestrial civilizations in our galaxy. Fermi’s question in 1950 (which became known as the Fermi paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and the lack of evidence for, or contact with, such civilizations. Fermi calculated that any advanced society could easily colonize (have colonized) all habitable planets in our Galaxy within 50 million years (even with the limits of today’s technology). So, where are they?
Dr. Frank Drake devised his equation in 1961 in preparation for a meeting of astronomers, physicists, biologists, social scientists and industry leaders at Green Bank, West Virginia, to establish SETI as a scientific discipline for estimating the number “N” of extraterrestrial civilizations we might sometime come into contact with. The seven variables considered in the equation are:
R* = the average rate of star formation per year in our galaxy
fp = the fraction of those stars that have planets
ne = the average number of planets that can potentially support life per star
fℓ = the fraction of the above that actually go on to develop life at some point
fi = the fraction of the above that actually go on to develop intelligent life
fc = the fraction of civilizations that develop a technology that releases detectable signs
L = the length of time such civilizations release detectable signals into space
Inserting the values for the conditional items above settled on at the time of the Green Bank Meeting in 1961, N works out as 10 × 0.5 × 2 × 1 × 0.01 × 0.01 × 10,000 = 10 civilizations.
The emerging field of astrobiology has brought an interdisciplinary approach to the Fermi paradox and the question of extraterrestrial life. What is it we call Life? Could life exist deep inside the Jovian planets? Within rocks? Why would it be beneficial to find life elsewhere? Is Europa a possible candidate for life? How likely is it, that life elsewhere may evolve as we see in science fiction shows? Why did we evolve the way we have? Why is it useful to know and understand astrobiology? What is Intelligence, is it problem solving, communication, Self Awareness (see image)?
Taking today’s best estimates into consideration, the value of N becomes 7 × 0.5 × 2 × 0.33 × 0.01 × 0.01 × 10,000 = 2.31. Not that much changed over the last 50 years. But if we now go be-yond the Milky Way and consider the estimated 3 x 1011 galaxies in the whole visible Universe, that puts the number of concurrent civilizations “somewhere between the common housefly and the common cold”, succinctly put in a recent debate hosted by Dr Allie Ford between Professor John Lattanzio and Ms Marion Anderson from Monash University on the topic “Intelligent Life is Common in the Universe”. Absence of Evidence is not Evidence of Absence, but...! We look forward to the next chapter in the continuing saga of Life in the Universe.
Some searching questions were put to Dr Allie Ford during question time, before the President, Perry Vlahos gave the vote of appreciation to general acclaim.