Astronomers Keep Using Bad Reasoning About Extraterrestrial Life

 For many decades scientists have been asked about the possibility of extraterrestrial life.  Again and again they have been posed these questions:

• Are we alone in the universe?
• Is there life on other planets?
• Is there intelligent life on other planets?
• Do extraterrestrial civilizations exist?

It seems that a large fraction of the time that scientists are asked these questions,  they reply by giving a fallacious argument. One such argument may be called the "many chances equals many successes" argument. The argument may be stated like this:

"There are billions of planets in our galaxy, so there must be many planets on which life exists."

"There are billions of planets in our galaxy, so there must be many planets with extraterrestrial civilizations."

"There are a vast number of planets in our universe, so life must have arisen many times."

"There are a vast number of planets in our universe, so there must be very many civilizations on other planets."

"There are a huge number of planets in our universe, so there must be many other extraterrestrial civilizations."

A very similar  argument may be called the "many chances equals some successes" argument. The argument may be stated like this:

"There are billions of planets in our galaxy, so there must be some  planets on which life exists."

"There are billions of planets in our galaxy, so there must be some planets with extraterrestrial civilizations."

"There are a vast number of planets in our universe, so life must have arisen on some other planets."

"There are a vast number of planets in our universe, so there must be some other civilizations on other planets."

"There are a huge number of planets in our universe, so there must be some other extraterrestrial civilizations."

We have an example of such a fallacious argument right at the beginning of the Netflix TV show "The Hunt for Planet B." We hear MIT scientist named Sara Seager say this:

"Well let me just say that in our own Milky Way galaxy there are a hundred billion stars and we now believe in our universe we have more than a hundred billion galaxies. So if you just do the math, the chance that there's a planet like earth out there with life on it is very high."

This is fallacious reasoning. You do not "do the math" by merely computing the total number of chances for an unlikely event to occur.  That's not "doing the math," but doing only half of the math.  Unless you have also estimated the chance of success on any one trial, you have only done half the math.  Seager follows her junk reasoning with the extremely false claim that "scientists never like to speculate." 

We also had an example of such a fallacious argument, stated by some British astronomer (Dame Maggie Aderin–Pocock). In the Daily Mail we read this:

"'In the whole of the universe there are approximately 200 billion galaxies,' Dame Maggie told the Daily Mail. 'And so although certain conditions were in place for life to start here on Earth, and this is the only example we have of life, I'm absolutely convinced that there's life out there, because with so many stars, so many planets, why would it just occur here?'

Such reasoning is completely fallacious. It is not at all true in general that "many chances equals many successes." It is also not at all true in general that "many chances equals some successes" or even that "many chances equals at least one success." If the probability of something happening is sufficiently low, then we should expect many chances to yield zero successes.  So "many chances" does not necessarily equal "many successes," and "many chances" does not necessarily equal "some successes" or even one success. For example:

• If everyone in the world threw a deck of cards into the air 1000 times, that would be almost 10 trillion chances for such flying cards to form into a house of cards. But we should not expect that in even one case would the flying deck of cards accidentally form into a triangular house of cards. 
• If a billion computers around the world each made a thousand attempts to write an intelligible book by randomly generating 100,000 characters, that would be a total of a trillion chances for an  intelligible book to be accidentally generated. But we should not expect that even one of these attempts would result in the creation of an intelligible book. And we should not even expect that even one of these attempts would result in the creation of a single well-spelled paragraph of more than 200 words. 
• If you buy a million tickets in a winner-take-all lottery in which the chance of winning is only 1 in 100 million, you should not expect that any one of those tickets will succeed in winning such a lottery. 

Below are some very general observations about probability:

• It is not necessarily true that many chances (also called trials) will yield many successes. 
• It is not necessarily true that many chances (also called trials) will yield some successes or even one success. 
• If the chance of success on any one trial multiplied by the number of trials gives a number less than 1, we should not expect that even one of the trials will produce a success.
• If the chance of success on any one trial multiplied by the number of trials gives a number greater than 1, we should  expect that at least one of the trials will produce a success.

Aderin–Pocock's language quoted above is very unwise. She has used a fallacious "many chances equals some successes" argument, and told us that because of this kind of reasoning she is not merely persuaded of a likelihood of extraterrestrial life but "absolutely convinced."

The origin of life from unguided processes is exactly the type of very-low-probability event that we should never expect to occur accidentally, even given a universe of 200 billion galaxies, each stacked with billions of planets. Below are some quotes from scientists and a doctor. 

• "The transformation of an ensemble of appropriately chosen biological monomers (e.g. amino acids, nucleotides) into a primitive living cell capable of further evolution appears to require overcoming an information hurdle of superastronomical proportions (Appendix A), an event that could not have happened within the time frame of the Earth except, we believe, as a miracle (Hoyle and Wickramasinghe, 1981, 1982, 2000). All laboratory experiments attempting to simulate such an event have so far led to dismal failure (Deamer, 2011; Walker and Wickramasinghe, 2015)." -- "Cause of Cambrian Explosion - Terrestrial or Cosmic?," a paper by 21 scientists,  2018. 
• "Biochemistry's orthodox account of how life emerged from a primordial soup of such chemicals lacks experimental support and is invalid because, among other reasons, there is an overwhelming statistical improbability that random reactions in an aqueous solution could have produced self-replicating RNA molecules."  John Hands MD, "Cosmo Sapiens: Human Evolution From the Origin of the Universe," page 411. 
• "The ongoing insistence on defending scientific orthodoxies on these matters, even against a formidable tide of contrary evidence, has turned out to be no less repressive than the discarded superstitions in earlier times. For instance, although all attempts to demonstrate spontaneous generation in the laboratory have led to failure for over half a century, strident assertions of its necessary operation against the most incredible odds continue to dominate the literature." -- 3 scientists (link).
• "The interconnected nature of DNA, RNA, and proteins means that it could not have sprung up ab initio from the primordial ooze, because if only one component is missing then the whole system falls apart – a three-legged table with one missing cannot stand." -- "The Improbable Origins of Life on Earth" by astronomer Paul Sutter. 
• "Even the simplest of these substances [proteins} represent extremely complex compounds, containing many thousands of atoms of carbon, hydrogen, oxygen, and nitrogen arranged in absolutely definite patterns, which are specific for each separate substance. To the student of protein structure the spontaneous formation of such an atomic arrangement in the protein molecule would seem as improbable as would the accidental origin of the text of Virgil's 'Aeneid'  from scattered letter type." -- Chemist A. I. Oparin, "The Origin of Life," pages 132-133.
• "The expected number of abiogenesis events is much smaller than unity when we observe a star, a galaxy, or even the whole observable universe." -- Scientist Tomonori Totani, "Emergence of life in an inflationary universe," a paper confessing we would not expect one natural origin of life (abiogenesis) even in the entire observable universe (link).
• "The advent of life from prebiotic origins remains a deep and possibly inexplicable scientific mystery." -- Scientist Stephen Mann (link). 
• "The origin of cells is shrouded in near-total mystery." -- A recent biology textbook written by scientists (link). 
• "We now know not only of the existence of a break between the living and non-living world, but also that it represents the most dramatic and fundamental of all the discontinuities of nature. Between a living cell and the most highly ordered non-biological system, such as a crystal or a snowflake, there is a chasm as vast and absolute as it is possible to conceive." --  -- Michael Denton, MD and biochemistry PhD, "Evolution: A Theory in Crisis," page 250.
• "Thus, the chances of getting the right sequence of amino acids in a protein of 100 amino acids in length by random chance is 1 in 60¹⁰⁰ or 1 in 6.53 × 10¹⁷⁷. In the vernacular, that would be considerably less than 'slim to none.'  But that is just the odds of selecting the amino acids in the correct order; we still have some chemistry to do to combine them in the proper way via peptide bonds. Making proteins via undirected chemical reactions is beyond hard. Based upon these odds, it is impossible." -- Chemist Ed Peltzer, discussing the luck required to get only one of the many proteins needed for an accidental origin of life (link). 
• "Now people will argue that given the tremendous size of the ocean and the time involved, there is a tremendous resource for the many possibilities. I would argue that it does us no good to have the essential proteins scattered about the ocean and millions of years apart. We need all of them simultaneously and in the same spot. And that spot is tiny. A typical bacterial cell is very small. They range in size from 0.2 to 2.0 μm in diameter and 2 to 8 μm in length or 63 atto-L to 25 femto-L (63 × 10-18 L to 25 × 10-15 L) in volume.  So, time and chance are of no help here....Abiogenesis needs an external source of information that random undirected chemical reactions can never provide." -- Chemist Ed Peltzer,  (link).
• "Over the past few decades biologists have further unravelled the mind-blowing complexity of life at the molecular level and consequently laid bare its super-astronomical information content. Such a complexity is manifest for instance in the arrangements of amino acids in crucial enzymes, or nucleobases in DNA. The precise 'information' contained in enzymes— the arrangements of amino acids into folded chains—is transmitted by way of the coded ordering of the four nucleotide bases (A,T,G,C) in DNA. In a hypothetical RNA world, that some biologists think may have predated the DNA-protein world, RNA is posited to serve a dual role as both enzyme and transmitter of genetic information. If a few such ribozymes are regarded as precursors to all life, one could attempt to make an estimate of the probability of the assembly of a simple ribozyme composed of 300 bases. This probability turns out to be 1 in 4³⁰⁰, which is equivalent to 1 in 10¹⁸⁰, which can hardly be supposed to happen even once in the entire 13.9-billion-year history of the canonical Big Bang universe. And this is just for a single enzyme. In the simplest known bacterium M. genitalium with some 500 genes coding for enzymes the improbability escalates to a super-astronomical scale." -- 3 scientists (link).  
• "There is absolutely no evidence that life began on Earth. The problems with an Earth-centered abiogenesis can be summed up as follows: A) Complex life was present on Earth almost from the beginning. B) ...There was not enough time to create a complex self-replicating organism. C) DNA and complex organic molecules would have been destroyed by the environment of the early Earth. D) All the essential ingredients for creating life were missing on the new Earth. E) There is no evidence that life has been or can be produced from non-life on this planet." -- 2 scientists (link). 
• "The mathematical likelihood of finding RNA elsewhere in the universe is basically zero,” -- Lee Cronin, an expert in prebiotic chemistry (link). 

Below is a screen shot from a page showing the curriculum requirements to get a Master's Degree in astronomy at the University of California at San Diego. There is no course in probability mathematics. There is no course in biology. There is no course in chemistry. So why would anyone think that an astronomer is qualified to competently estimate the likelihood of life arising by unguided processes on other planets, by accidental chemical events?

It is possible that there is life on many other planets, but only if some purposeful agency is involved, some transcendent causal factor that overcomes the otherwise insurmountable odds of the accidental origin of life. 

The latest example of zany talk by astrobiologists is discussed in a recent post by Harvard astronomer Avi Loeb promoting a nutty-sounding proposal for looking for signs of extraterrestrial life:

"A detailed preprint, posted recently here, suggests a new path in the search for technological signatures of extraterrestrial civilizations. The idea is to analyze a cubic meter of lunar regolith and look for sub-micron dust particles that might be relics from long gone technological structures of past civilizations in the Milky-Way galaxy. Such particles may survive over billions of years in their journey through interstellar space and eventually land on the lunar surface."

Science at its wackiest