Fred Hoyle’s Junkyard Fallacy

| July 22, 2012

Panspermia (attrib: Wikipedia)

The eminent astronomer and cosmologist Sir Fred Hoyle was a proponent of a theory called Panspermia, where his belief was that life on earth was deliberately seeded by organic molecules by an alien intelligence.    It is an interesting theory, and since we have already seen the absorption spectra of organic molecules in outer space, some kind of seeding, intentional or not is not out of the question.

The problem is that we have no way of testing that explanation at the moment, so we keep it on the shelf labeled, Very Fascinating Speculation.    As  a proponent of his theory, however, Hoyle commits what I have labeled The Junkyard Fallacy, which is a collection of formal fallacies and faulty logic.

In his article in Nature1 in 1981, Hoyle calculates the probability that  the 2000 enzymes that make up the proteins and amino acids necessary for modern organic life form themselves out of sheer random chance.   He comes up with the astronomically low probability of  1/10^{4000}.   This would be one chance in 10 followed by 4000 zeroes.   Naturally, these kinds of numbers are the closest to impossible that we can get.     Most people who have analyzed Hoyle’s calculation since that time have not disputed it in any serious way, so we can certainly go with that as a working number of “impossible”.

Hoyle then illuminates the situation with a colorful analogy as follows:

(attrib: LA Times)

A junkyard contains all the bits and pieces of a Boeing-747, dismembered and in disarray. A whirlwind happens to blow through the yard. What is the chance that after its passage a fully assembled 747, ready to fly, will be found standing there? – Fred Hoyle (Nature294, (1983), p.10)

And there is no reason to dispute Hoyle’s implication that after the whirlwind is done there will be no 747 standing there.

There is a problem with these scenarios, though, that is very misleading.   It is like a magician’s trick where your eyes are distracted by the activity of one hand, while the other hand performs the mechanics of the trick.   Buried in both the enzyme probability calculation and the junkyard analogy is the implicit assumption that only random chance can produce enzymes or 747s.   To illustrate this, let’s back up and consider the whirlwind itself for a moment, because it is a simpler analogy.   I would like to demonstrate that tornadoes are formed by alien intervention. so let me make my own probability proclamation:

A body of  calm air in our atmosphere contains all the molecules necessary to produce a tornado with enough force to destroy parts of a city.  What is the probability of all those molecules coming together by random chance and forming a tornado? – Dudley Chapman

Suppose we could do that probability calculation.   Would we have just demonstrated that tornadoes are formed by alien intervention?  I really don’t think this would stand up in the court of scientific inquiry.   One thing that we do know is that enzymes, tornadoes, and 747s actually exist, so their probability of coming about by some process or other is 100%.   So there must be something wrong with our analogy.

Tornado Formation
(attrib: Encyclopedia Brittanica)

Looking at the tornado example, the problem is obvious.   An assumption was made in the last sentence that the process for which tornadoes are formed is random chance.    With what we know about weather system formation these days, we are quite knowledgeable about the process of tornado formation, and random chance is certainly not a big player in that process.  So the first flaw in my alien tornado maker scenario is that I have unwittingly or deliberately chosen a bad process as a suggestion for how tornadoes are formed without alien intervention.

In logic and debate terminology, I have erected a Straw Man Fallacy, which means I have attempted to refute someone’s argument by creating my own false version of it and refuted that instead.      In that my tornado analogy is attempting to refute the notion that tornadoes can form from purely unguided natural process, I have erected a Straw Man process of pure random chance in place of the real process.

The next fallacy that is implicit in my alien tornado maker argument is another well-known fallacy called Appeal To Ignorance.   In this case the term “ignorance” does not mean stupidity, but rather a simple lack of knowledge about something.  It might be easier if the logic steps are laid out step by step:

Proof of Hypothesis –   Tornadoes are caused by alien intervention:

  1. Tornadoes exist.
  2. Tornadoes cannot form by random chance.
  3. Therefore, tornadoes must be caused by aliens.

Laid out this way, you can see that #2 is the first part of a straw man fallacy, where random chance is suggested as the only way that tornadoes could form without alien intervention.    The idea of the straw man is to get you to concede that there is no way that tornadoes can form by a natural process.   My hope is that the random chance reference will jangle your intuition strongly enough for you to say, “Of course, that would be ridiculous”.  This forms a vacuum of natural explanations for a moment (hopefully you are not a meteorologist), that I can fill with my alien tornado maker explanation.

This vacuum of alternative explanations represents an ignorance of other explanations.  In some cases the ignorance comes from simply not knowing the actual explanation, and in other cases it comes from the fact that we have no other explanation as of yet.  (Suppose we were having this discussion in the year 1300 AD where we had no other explanation for how tornadoes are formed).    So the leap from step #2 to step $3 appeals to our ignorance of some other explanation.    That is why it is called an Appeal To Ignorance, or more formally, Argument From Ignorance.     One can state it formally this way, “X is true, because we have no evidence that it is not true.”  Or, “X is the explanation, because we have no other explanations.”

So for the 1300 AD version, spelled out with all the logic steps:

Proof of Hypothesis – Tornadoes are created by sorcerers:

  1. Tornadoes exist.
  2. Tornadoes cannot form by random chance.  (true enough)
  3. We have no other explanation for tornadoes.  (its the year 1300 so we are ignorant of the actual process).
  4. Therefore, tornadoes are created by sorcerers.  (from 2 and 3, by Appeal To Ignorance).

(attrib: Magic: The Gathering)

Notice that my tornado proof might work in the year 1300 because my “random chance” straw man process would be the only thing we would be able to think of for how tornadoes might form naturally.  So we might conclude that tornadoes must be caused by sorcerers, wizards, or demons.   But that line of reasoning (as fallacious as it might be) would only last until we actually discovered a real natural process for how tornadoes can form.   And it would be obvious that my hypothesis does not detect aliens, but rather it detects ignorance.   In real science, the right answer would be (with what we knew in 1300 AD):

  1. Therefore, we have no testable hypothesis as of yet for how tornadoes are formed.

So getting back to Hoyle’s junkyard analogy, we can see that Hoyle has chosen a Straw Man process of random chance for how 747s might be formed, and he cast it in the form of a tornado (or whirlwind).    Hoyle knows how a 747 is really made and he assumes that we do too.   So he is not trying to demonstrate that aliens make 747s.   What he is hoping is that the junkyard analogy will be vivid enough to distract you from the real task at hand.

And his real task at hand is for you to overlay the Straw Man and Appeal to Ignorance fallacies onto the creation of life problem and conclude that life on earth must have been seeded by aliens.   Laying out the logic as we did with tornadoes:

  1. Organic life requires 4000 enzymes.   (true enough)
  2. It is impossible for 4000 enzymes to form by random chance.  (Straw Man process of random chance)
  3. Therefore, life on earth was seeded by aliens.  (Appeal to Ignorance).

No scientist expects that enzymes, proteins, and amino acids formed by random chance.    We expect that there are other mechanisms that formed  the precursors for these things.  And that those mechanisms became as self-replicating as the ones we see all around us today in the vast and rich diversity of life on earth.    It certainly does appear that the conditions under which those kinds of processes got jump-started are very special and rare indeed.   But appealing to logical fallacies to exploit someone’s intuition whether deliberately or unwittingly is not a good way for investigating the natural world.

The right answer at the moment is that we have no comprehensive testable hypothesis for how the first life was formed.

I do want to acknowledge that Sir Fred Hoyle was a preeminent scientist who made valuable contributions to astrophysics and cosmology.  But often when a scientists waxes philosophical on the big questions of life that lie outside their field, they can sometimes let their emotions run away with them.   The question of the origin of life is one of those questions that make all of us weak in the knees no matter what we believe brought it about.   This one particular junkyard fallacy seems to pop up in many different forms in the musing of scientists on origins questions who are working outside their field.    It doesn’t make it anymore valid, though, for the obvious reasons.

We do have to also admit that the question of the origin of life is one of the most fascinating questions facing us scientifically, emotionally, philosophically, and theologically.   And we also have to admit that the processes that underlay biology in general is probably more complex and challenging than any of our most difficult physics or chemistry challenges.   And we also have to admit that with no fully comprehensive explanation for the origin of life on Earth, Hoyle’s Panspermia speculation is not out of the question.   It doesn’t solve  the basic question, though, but rather simply outsources the question to some other location off of the Earth.

From a Theistic Evolutionist Perspective

One might also ask why a site such as this one would spend so much time exposing an argument form that is often used to justify Intelligent Design hypotheses with the aim of demonstrating the need for God’s providence on the creation of the universe, of life, and the ongoing creative force in the evolution of life.   The answer to that question is the same as most of the Christian denominations would tell you.  And that is that God’s divine providence is not contingent on our understanding what natural processes with which God used to create something or to sustain something with.   God doesn’t have to lurk only in the shadows of our ignorance of natural process.   He is not the God of ignorance, rather he is the God of truth, whether we know the truth or not.

The processes that may have brought about the origin of life are no different in that respect than simple processes like forces accelerating masses.    We Christians do not think that God had to get out of the “moving of objects” business the moment Newton characterized all known properties of motion.   Similarly, we don’t think that God will have to get out of the “life creation” business when we discover the processes that God used to do that creating. This is why the denominations that represent most of the world’s  Christians accept scientific explanations for such things as the origin of the universe or the evolution of life on the same basis that science does.

And naturally, what we don’t want is that our Christian testimony to have to rely on logic tricks, fallacies, and misdirection.   That has no place under the banner of Jesus.

All truth is God’s truth, including scientific truth. Let’s stop manipulating the naive intuition of people of tender and sincere faith with logic trickery and go out and really find the mechanisms behind God’s creative action in the world.


  1. Fred Hoyle(1983): “The Intelligent Universe”, page 19. The Boeing 747 metaphor is reported in Nature294 (1981), p.10

Tags: , , , , , , ,

Category: How Did Life Originate, Logical Fallacies, Science and Evidence

About the Author ()

Comments are closed.