Physicists have a reputation for being very good at math. But when they discuss two different topics, physicists often sound like they are bad at math. The first topic I refer to is the topic of cosmic fine-tuning, the many ways in which our universe seems to have defied the odds so dramatically it is like someone firing ten arrows that each hit the center of ten bullseye targets 200 meters away. When discussing this topic, physicists sound as if they cannot put two and two together, as I discuss in my post here.
There is one other topic that makes physicists sound like they are bad at math as soon as they begin discussing it: the topic of the probability of extraterrestrial civilizations arising by blind accidental causes. An example of their clumsy utterances on such a topic is found in the 2025 article "The existence of intelligent aliens is 'highly likely' — and they could await in our own galaxy" by biophysicist Maikel Rheinstadter. Rheinstadter goes wrong in quite a few places.
He starts out with six paragraphs of triumphalist boasting that has nothing to do with the topic of his post. Then he asks: what is life? He offers a very bad definition of life: "A more comprehensive definition considers life as a self-sustaining chemical system capable of processing information and maintaining a state of low entropy, with little disorder or randomness." That sounds like a definition of life that only a physicist would give.
A decent definition of a living thing is: a very information-rich state of extremely high organization, requiring many types of protein molecules that each require a very special arrangement of thousands of atoms to achieve a functional end, with the information-rich state of organization being capable of reproducing itself or participating in its reproduction, either sexually or asexually. That definition applies to everything from single-celled organisms to fish to mammals.
Rheinstadter then proceeds to make the very serious error of stating the Great DNA Myth, the untrue claim that organisms have within their DNA instructions for building themselves. He erroneously states, "DNA serves as the blueprint of life, containing the genetic instructions necessary for an organism's development, survival and reproduction." No, DNA does not contain any instructions telling how to build a human or any of its organ systems or any of its organs or any of its cells, and DNA does not even have instructions on how to build any of the organelles that are the building components of cells.
Rheinstadter then wastes paragraphs speculating about the possibility of silicon life, which has nothing to do with estimating the likelihood of chance processes producing intelligent extraterrestrials. He then makes a statement sounding like he has no idea about the astronomical odds against any accidental origin of life from non-life. He states this: "On the other hand, geochemical processes on early Earth, such as those occurring in warm little ponds or in hydrothermal vents deep in the ocean, could have also provided the necessary conditions and ingredients for life to emerge." Talking about "the necessary conditions and ingredients for life to emerge" is an extremely misleading way to talk. Even the simplest living thing is a state of physical organization as great as the state of physical organization in a book. You don't get life by just having some suitable conditions and ingredients, just as you don't get books spontaneously arising from ingredients of paper and ink.
Rheinstadter then discusses homochirality, but in a very misleading way that is a kind of "censor the improbability" affair. Homochirality is the fact that the amino acids in the proteins used in living things are all left-handed, even though naturally produced amino acids are left-handed and right-handed in equal numbers. Homochirality is one of several gigantic reasons for believing in the impossibility of natural abiogenesis. There naturally would never occur a situation in which you got some very large pool of amino acids that were only left-handed.
Failing to explain the homochirality issue, Rheinstadter inaccurately claims that "recent analyses of meteorites have revealed a slight asymmetry, favouring the left-handed form by as much as 60 per cent." No, reliable analytics have not revealed such a thing, and all analytics of amino acids in meteorites are extremely unreliable because of the very high chance of earthly contamination.
Referring to the Drake Equation, Rheinstadter claims. "An optimistic estimate using this formula suggests that 12,500 intelligent alien civilizations might exist in the Milky Way alone" He has a link to a Popular Mechanics page that has only a headline and not a story.
Rheinstadter concludes with the statements below, which are all examples of a physicist sounding like he is bad at math:
"The primary argument for extraterrestrial life remains probabilistic: considering the sheer number of stars and planets, it seems highly improbable that life wouldn't have arisen elsewhere.
The probability of humanity being the sole technological civilization in the observable universe is considered to be less than one in 10 billion trillion. Additionally, the chance of a civilization developing on any single habitable planet is better than one in 60 billion.
With an estimated 200 billion trillion stars in the observable universe, the existence of other technological species is highly likely, potentially even within our Milky Way galaxy."
The first of these statements is a statement guilty of the "many chances equals some successes" fallacy, a fallacy that might also be stated as "many chances equals at least one success." It simply is not generally true that many chances will result in some successes, or that many chances will result in at least one success. If the chance of something is sufficiently low, it will not happen even if there are a huge number of chances of it happening.
The correct way to calculate the chance of something happening by chance is to multiply two numbers:
(1) The chance of success on any one random trial.
(2) The number of random trials that occurred.
If the resulting number is greater than 1, then at least one success is likely. If the resulting number is less than 1, then at least one success is unlikely.
For example, the probability of throwing ten dice and having them all end up sixes is 1 in six to the tenth power, or 1 in 60,466,176. If you put ten dice in a cup, shake the cup, and throw the dice on the ground a million times, you should not expect to ever see all ten dice landing as sixes. If you try such a thing 100 million times, you should expect to see at least one such try produce ten sixes. The example illustrates the simple fact: many chances may not mean a likelihood of even one success.
To sound like someone who was good at math, what Rheinstadter should have done is to have first made an estimate of the likelihood of life and a civilization appearing on a planet, and then referred us to the number of planets in the observable universe, telling us perhaps that given such an estimate of the chance of life and a civilization appearing, we should expect at least one extraterrestrial civilization to exist. But he did not do that. Instead he acted as if he believed in the erroneous "many chances equals some successes" idea, by saying, "The primary argument for extraterrestrial life remains probabilistic: considering the sheer number of stars and planets, it seems highly improbable that life wouldn't have arisen elsewhere."
But where Rheinstadter really fails to sound like someone good at math is in his statement, "The probability of humanity being the sole technological civilization in the observable universe is considered to be less than one in 10 billion trillion." Here he is completely misstating what was said by the article he refers to. The source he is referring to is one that merely said that if the likelihood of a technological civilization appearing on a planet is greater than 1 in 10 billion trillion, then we should expect that there exists at least one technological civilization in the universe. It is gigantically inaccurate to cite that source and say that it claimed that "the probability of humanity being the sole technological civilization in the observable universe is ... less than one in 10 billion trillion." In fact, the source refers to a paper whose co-author says, "We have no idea how likely it is that an intelligent technological species will evolve on a given habitable planet."
Rheinstadter has mangled his math. He has referred to a study that did nothing to claim any likelihood, and he has incorrectly claimed that this is a study claiming near-certainty. The mistake that Rheinstadter made here is as clumsy as hearing David merely say, "If I get a 99 on the test, it will be probably the best score in the class," and then claiming, "David says there is a 99 percent chance that he got the best test score in his class."
Nowhere in his article does Rheinstadter sound like someone who is good at probability math. In one of the sources that Rheinstadter cites, we hear another physicist (astrophysicist Adam Frank) who stops sounding like he's good at math as soon as he discusses extraterrestrials. On the page cited, we have this quote:
"By applying the new exoplanet data to the universe’s 2 x 10 to the 22nd power stars, Frank and Sullivan find that human civilization is likely to be unique in the cosmos only if the odds of a civilization developing on a habitable planet are less than about one in 10 billion trillion, or one part in 10 to the 22nd power. 'One in 10 billion trillion is incredibly small,' says Frank. 'To me, this implies that other intelligent, technology producing species very likely have evolved before us.' "
How very silly, to reason that we should be suspicious of a probability because it is "incredibly small." There are more than 1,000,000,000,000,000,000,000 probabilities that you could correctly calculate as being "incredibly small" and having a likelihood as very much smaller than 1 chance in 10 the 22nd power. There is no rule in the universe that probabilities cannot be incredibly small, or that most probabilities are more than incredibly small.
How could a physicist sound like he is good at probability math when calculating the chance of extraterrestrial life? It would go something like this:
(1) First, he would study the likelihood of a random set of amino acids resulting in a functional protein, keeping in mind that proteins are very sensitive to small changes, and that the average protein requires hundreds of specially arranged amino acids. A key part of the calculation is that there are twenty possible amino acids used by living things.
(2) Under a reasonable assumption that at least half of a functional protein's amino acid sequence is necessary for it to have any function, he would make a rough calculation that the probability of getting a functional protein by chance combinations of amino acids is roughly 1 in 10 to the hundredth power.
(3) He would consider the minimum number of functional proteins in a self-reproducing cell, which is at least 100.
(4) Using the rule that you get the probability of independent events all occurring by multiplying their individual probabilities, he would calculate that the chance of amino acids accidentally forming into a collection of all the proteins needed for a self-reproducing cell is roughly 1 in 10 to the ten-thousandth power, or roughly 1 in 1010000.
(5) He would calculate the total number of chemical combinations that might occur on all of the planets in the observable universe, assuming a generous figure of maybe 10 to the seventieth power per planet, and an estimate of ten to the 23rd power planets in the universe.
(6) Taking into account the numbers the numbers above, the result would be a likelihood of less than 1 in 10 to the hundredth power of the necessary combinations ever occurring anywhere in the observable universe, because of mere chance processes.
(7) He would note that there are many other requirements for the origin of even the simplest life, such as homochirality requirements making the probability gigantically smaller, and also the requirement for the origin of a genetic code, also making the probability gigantically smaller.
(8) He would end up by concluding that there is a negligible likelihood of chance processes ever producing a self-reproducing cell anywhere in the observable universe.
Some physicists or astrophysicists sounded like they did make the appropriate calculations. They are quoted below:
- "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.
- "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 situation in regard to extraterrestrial life is this: the universe may contain gigantic numbers of inhabited planets, but only if there is some causal reality increasing the odds (as there might well be). If only blind chance is at work, we should conclude that Earth is the only planet in the observable universe with living things. But since there are the strongest reasons for believing that something much more than blind chance is at work, we cannot draw any such conclusion about a likely nonexistence of extraterrestrials.
The question of teleology and cosmic purpose is all-important in considering extraterrestrial life. But senselessly physicists and astronomers ignore such a question.
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