Nowadays academia professors tend to be people with limited knowledge concentrated in one particular field. It is a mistake to assume that people who have concentrated their studies in one narrow area are knowledgeable about many related topics. For example, a professor of medieval history may have little knowledge of modern history.
Google Gemini infographic on scientist overspecialization
People often make the mistake of assuming that some very complex question involving many fields of knowledge will be well-handled by some person who specializes in only one of those areas of knowledge. Consider the important question: how high will the temperature grow later in this century because of global warming? It is a mistake to think that someone is well-equipped to answer that question merely because he calls himself a climate scientist. This is because the question involves many questions involving things other than just earth science and the atmosphere, including these:
(1) How high will the human population be later in this century? Fossil fuel use may be proportional to the number of people, but it is hard to predict the future population because of factors such as falling birth rates in many countries.
(2) How much progress will humans make in reducing fossil fuel use, by using alternate technologies such as solar power, wind power and nuclear power?
(3) Will there be some nuclear fusion breakthrough that greatly reduces the amount of fossil fuel use?
(4) Will fossil fuel use tend to dramatically drop off not mainly because of human concerns over global warming, but because of a Peak Oil scenario under which it becomes more and more expensive to extract oil from underground?
(5) Will there be technological breakthroughs that allow geoengineering efforts to roll back the amount of carbon dioxide in the atmosphere?
A climate scientist may have no expertise allowing him to give good answers to these questions very relevant to judging how high the average temperature will be later in the century. Expertise in one narrow subject does not mean you will give a good answer on a question involving very many subjects.
A type of article that pops up in the press every now and then is an article in which some astronomy professor tries to estimate the number of extraterrestrial civilizations in our galaxy or in our universe. The average person probably thinks that an astronomy professor can be trusted to give a reliable answer on that question. But such an opinion may be misguided, because the question involves so much more than just astronomy.
The question of the likelihood of extraterrestrial civilizations appearing involves all of these questions, almost all of which are outside of the domain of astronomy:
(1) How many planets not-too-big and not-too-small exist in the habitable zones of stable long-lived stars?
(2) What is the chance of life accidentally appearing on some suitable planet?
(3) What is the chance of life with simpler cells (prokaryotic cells) ever progressing to become life with far more complex cells (eukaryotic cells)?
(4) What is the chance of one-celled life ever progressing so that there exists on a planet large organisms with limbs and organs?
(5) What is the chance that there ever would appear on some planet with life some species with limbs capable of manipulating tools?
(6) What is the chance that a planet with life would ever produce intelligent creatures smart enough to use language and build a civilization?
(7) What is the chance that a technological civilization would destroy itself before long, so that it would not be available to communicate with other planets?
(8) Is it true that mere brain evolution explains the appearance of intelligence, or are there reasons for thinking that the existence of thinking, reasoning, and instantly recalling conscious creatures such as us cannot be explained by mere brain activity?
(9) Do we have reasons for thinking that we already have evidence of extraterrestrial intelligence, in the form of UFO sightings that cannot be explained without assuming extraterrestrial spacecraft?
(10) Are there reasons for believing that there exists some cosmic designer who might be interested in having intelligent life exist on many planets, so that the chance of extraterrestrial civilizations appearing might be greatly increased?
How many of these questions involve astronomy? Only one. So why do we think that astronomy professors are well-qualified to be addressing such questions?
The record of astronomy professors in estimating the number of extraterrestrial civilizations is a poor record. Moreover, in discussing some of the questions relevant to such an estimate, astronomy professors have long been guilty of misspeaking about some of the relevant factors in making such an estimate.
An example of such an astronomer who made great mistakes at such a task was Carl Sagan. Eager to promote the idea that extraterrestrial cultures were abundant in our galaxy, Sagan again and again misled his readers and those who listened to him in interviews. Making a grotesque misrepresentation of the complexity of the bodies of human beings, Sagan endlessly repeated the slogan "we are all star stuff." Human bodies are enormously organized marvels of fine-tuned functional complexity that are the opposite of "stuff" (a word meaning something disorganized). Sagan also repeatedly misled his readers and listeners by making the false claim that "the stuff of life" is scattered throughout the universe. The truth is that the lowest building components of living things are amino acids, which have been found in only the tiniest trace amounts in outer space, such as 1 part per billion on comets or interstellar molecular clouds.
In his book Intelligent Life in the Universe, Sagan dogmatically proclaimed on page 418 that "The number of extant civilizations substantially in advance of our own in the Galaxy today appears to be perhaps between 50 thousand and one million." The claim was as arbitrary and poorly established as Senator McCarthy's claims about there being 205 registered communists in the US State department. Just as McCarthy kept changing his estimate about the number of communists in the State Department, Sagan kept changing his estimates of the number of civilized planets in our galaxy. He would repeatedly claim that there were a million civilizations in our galaxy, and many of the times he made such estimates, he would try to suggest that whatever estimate he made was the estimate made by most astronomers, although he never gave any evidence to back up such a claim about a majority of astronomers agreeing with him, and never even backed up any claim that a large fraction of astronomers agreed with him.
A Scientific American article appearing a while ago gives us another example of why we should have little confidence in astronomy professors estimating the number of extraterrestrial civilizations. The astronomy professor author starts out by making the fallacious "many chances equals some successes" argument, the reasoning that extraterrestrial life must exist because there are so many chances for it to arise. There are maybe a billion trillion planets in the observable universe, but if the chance of the accidental origin of life on any planet is less than 1 in a billion trillion, it should be unlikely that life would ever accidentally appear elsewhere in the observable universe. And there are strong reasons for thinking that the chance of life accidentally appearing on any particular planet is less than 1 in a billion trillion, because of the very great organization needed for even the simplest self-reproducing cell. It is not generally true that many chances equals some successes or even a single success in any case where the probability of success per trial is very low.
The same astronomer gave no sign at all that he understands the huge levels of functional complexity, component interdependence and information richness in organisms such as humans. It's par for the course. The astronomer seemed to show no grasp of how fine-tuned a hierarchical organization of matter a human body is, but why should we think that he would? Astronomy is not biology.
A thorough study of all of the factors relevant for estimating the chance of extraterrestrial intelligence would include the study of whether brains are a credible explanation for human mental phenomena. Such a study would involve a very thorough study of the human brain and its physical shortfalls suggesting it cannot be the source of the human mind and human memory, and also a very thorough study of the human mind and human mental experiences, both common and extraordinary. That would be a type of study that few astronomers have done.









