Although I have observed or participated in a great many creationism/evolution debates, there are two questions I have never seen honestly and clearly answered by any creationist. And small wonder, because these two questions cut straight to the heart of the debate; it is my belief that they cannot be answered by one who is immovably biased. I have asked these questions many times, and while creationists have avoided them, disparaged them, ignored them, or responded to them with meaningless statements cloaked in confusing language, I have never seen any creationist answer them in an honest and forthright manner. I do not think any creationist can truly answer them. Still, I’m always willing to be proven wrong. If you are a creationist and feel you can answer these, e-mail me using the feedback link at the bottom of the page, and we will see what comes of it.
Question #1: What evidence would falsify your chosen variety of creationism?
Falsifiability is a necessary (though not a sufficient) condition for any explanation that would call itself scientific. If there is no possible way a hypothesis could be proven wrong, not even in principle, then it is not science.
There is more than one way to falsify a hypothesis. A hypothesis may make statements that do not fit with evidence already known. Or a hypothesis may make statements about evidence that will be discovered, and this prediction turns out to be incorrect. Finally, we may find evidence that should not exist if the hypothesis is true. Any of these criteria will suffice to make a scientific theory falsifiable, but it should be vulnerable to falsification – as virtually all theories are – on all three grounds.
Unfalsifiability occurs when a hypothesis is so nebulous or has so many qualifications tacked on that it can accommodate any imaginable evidence; it can also occur when a hypothesis makes no predictions whatsoever, or makes predictions that cannot be tested even in principle. An example of an unfalsifiable hypothesis is “Last Thursdayism” – the belief that an all-powerful, deceitful god created this universe only last Thursday but placed in it misleading evidence of older history, including putting the exploded remnants of stars that never existed in the sky, burying the fossilized remains of animals that never lived in the ground, setting all radiometric decay “clocks” to read the same false age, creating trees full-grown with rings recording growth patterns of years that never happened, and implanting humans with false memories to make them believe they have had a longer history. This hypothesis makes no predictions – it simply states that things should be just the way they are. Nor could anything disprove it – no matter what evidence we produce for the antiquity of the universe, the Last Thursdayist would simply reply that it is a trick, purposely designed to look old even though it actually is not. Since we are unable to put this idea to the test or disprove it with evidence, it is not falsifiable, and therefore it is not science.
Creationists of all varieties insist that their ideas are scientific and therefore deserving of being taught in public schools. To those creationists, I put this challenge: If your beliefs are scientific, how might they be falsified? What evidence, what discovery would convince you that your chosen brand of creationism (young-earth, old-earth, intelligent design, other) is incorrect and cause you to abandon it?
Clear, specific and detailed answers are required. Don’t say “evidence that the Earth is old”; describe exactly what evidence you would accept as demonstrating this. Don’t say “evidence that the global flood never happened”; describe clearly and specifically what geological evidence you would accept as demonstration that there was no global flood. Anything will do as long as it is evidence that could, at least in principle, exist, and as long as it is not a plainly useless, evasive or overbroad answer such as “I would accept that my brand of creationism is wrong if life did not exist”. If the universe, the Earth, life or humanity did not exist, obviously there would be no one around to verify that fact, and thus such an answer would fall into the category of evidence that could not even hypothetically exist. Any proffered answer must consist of evidence that could conceivably be found at some point in the future. Likewise, your answer must consist of evidence that is not at odds with already-known facts. The suggestion that your brand of creationism would be falsified if life did not exist falls into this category, as does, for example, a suggestion that your brand of creationism would only be falsified if life did not contain information, and since it clearly does your brand of creationism has passed all possible tests for falsification. No scientific theory, no matter how well-supported, ever reaches a point where it becomes immune to any further possibility of contradiction.
If you cannot provide an answer to this question, if your answer consists of some sort of evidence that could not exist, even hypothetically, or if your answer is so vague or so laden with qualifications that you have an escape hatch out of anything that is offered as satisfying it – in these cases, you have done nothing but further demonstrate that creationism is not falsifiable, and thus is not science.
If you are a creationist and feel you can answer this challenge, e-mail me and I will reply to your answer and post it on a webpage linked to this one. If you are a creationist and feel you cannot answer this challenge, I invite you to consider the implications of that fact.
Question #2: What evidence would you accept as provisional proof of evolution?
To explain the relevance of this question, it is necessary to state a simple fact: Science is not a game of musical chairs.
In other words, the objective in science is not simply to be the last person left standing. The situation frequently arises that there are multiple hypotheses offered to explain a given phenomenon. But to prove any one hypothesis correct, it is not enough just to falsify all its competitors. After all, even if all the other explanations are wrong, that explanation might be wrong as well, and the true answer might be something no one has thought of yet. Any scientist seeking to prevail in this competition must establish that their own hypothesis can accommodate the existing evidence and does not have any serious unresolved problems or contradictions of its own.
Creationists frequently dispute this principle, asserting that if evolution is disproven, creationism wins by default. But this is not so. It is true that life either evolved or did not. This does not mean that the only options are naturalistic neo-Darwinian evolution or supernatural six-day creation by the Christian God six thousand years ago. Phrased in such a manner, this dilemma is plainly a false one. There are countless other options, for example, non-Darwinian evolutionary theories, or the creation stories of other religions of the world, yet creationists sometimes ignore these other options and insist that there are only two choices in the debate over origins.
But since this is not the case, this second question is not redundant. It would be fallacious to claim that evolution must be true simply because creationism is false; like any other scientific theory, evolution must be able to stand on its own merits before we are justified in accepting it as true.
With that in mind, I offer this second challenge. As part of their bid to get their beliefs taught as science, creationists frequently assert that their rejection of evolution does not arise from religious bias, but because they feel the evidence does not support it.
And so I ask creationists of all varieties, what evidence would you accept as supporting evolution? What evidence would be sufficiently persuasive to overcome your doubts and convince you to accept it?
By “evolution”, I mean the modern neo-Darwinian synthesis currently held by mainstream biology as the unifying theory best able to explain the diversity of life: the theory that life undergoes large-scale change over time as the result of random mutations filtered by natural selection, with subsidiary mechanisms such as genetic drift and symbiosis also playing a role, resulting in the appearance of new genes, new adaptations and new species.
Again, any offered answer to this question must be evidence that could hypothetically be discovered in the future, and your answer must be clear, detailed and specific. Do not say “a transitional series”; give a hypothetical example of a series of fossils that you would accept as transitional, clearly and in detail describing the qualities and features they would possess. Do not say “a mutation that produces new genetic information”; give an objective way to measure information and then describe in as much detail as possible a hypothetical mutation that would increase it according to your metric.
Also note that your answer must consist of evidence that is actually predicted by evolution to exist. Evolution does not predict, for example, that dogs will give birth to cats, bananas will grow from apple seeds, or that any such single-step saltational leaps will occur. Since evolution is not concerned with the origin of the cosmos, the origin of the Earth or the origin of life, but only the subsequent diversification of life once it already existed, any answer relating to the former three categories would also be irrelevant.
If you are a creationist and feel you can answer this challenge, e-mail me and I will reply to your answer and post it on a webpage linked to this one. If you are a creationist and feel you cannot answer this challenge, again, I invite you to consider why not.
There are some creationists, I am aware, whose belief in creation is a matter of faith not dependent on empirical evidence. With those, I have no quarrel. But the creationists who insist that their belief system is scientific, is supported by the evidence, is deserving of being taught in public schools – such people have no excuse if they cannot answer these questions in an honest and straightforward manner. Being able to answer questions like these is a minimal qualification for any hypothesis that would claim the mantle of science. I have found that, for all their rhetoric, creationists simply cannot answer these simple, fundamental questions, and this is just one further proof that creationism, while it may be acceptable as religion, is not and can never be science.
 To use a hypothesis to derive statements about reality and see if those statements correspond to already known facts is frequently called retrodiction. For example, for a long time it was known that there was a slight deviation in the orbit of Mercury that could not be explained by standard Newtonian gravitational physics. After Albert Einstein wrote down his equations of general relativity, which were slightly different from Newton’s, he used them to retrodict what the deviation in Mercury’s orbit should be. The result, by his own admission, gave him heart palpitations – the deviation that his equations predicted was identical to the deviation observed to exist. Had the two not matched, general relativity would have been falsified.
 Again, general relativity provides an example. After Einstein’s successful retrodiction of the deviation in Mercury’s orbit, he used his equations to predict that light from distant stars should be bent slightly by the gravity of our sun or other massive objects, causing the apparent position of those distant stars to change slightly. No such phenomenon was known at the time, but subsequent searches discovered that it did occur. Had this phenomenon not been observed to occur where general relativity predicted it would occur, general relativity would have been falsified.
 Continuing the example, if Einstein was correct, we would never expect to observe an object with positive rest mass traveling at a velocity greater than the vacuum speed of light. Special relativity predicts that this is impossible, and if such an object is ever discovered, we will be forced to discard that theory.