Tuesday, December 7, 2010

Questions for Young-Earth Creationists

Last Wednesday, Kentucky Governor Steven Beshear announced that millions of dollars in taxpayer funds will be going to Ark Encounter, a planned Christian creationist attraction similar in theme to the infamous Creation Museum (also in Kentucky).  Both attractions are sponsored by Answers in Genesis, a particularly zealous creationist group that adheres to a Young-Earth cosmology as part of their belief in a literal interpretation of the Bible.  According to their beliefs, the Earth and the heavens are somewhere in the vicinity of 6,000 years old.

As you would imagine, this has sparked the usual debate over separation of church and state, and of course I'm inclined to agree with those who really don't want their money going towards such things.  But the Governor seems to have mostly diffused the controversy on economic grounds, noting that the attraction will generate millions in tax revenue and create hundreds of jobs.

In light of this rejuvenated debate, I thought it might be a great time to present my Questions for Young-Earth Creationists, which I promised several months ago.  Here goes:

1. Do you believe that the speed of light is approximately 300,000 kilometers per second?  If you don't, how fast is it?  And how do you know that?
The actual speed of light is 299,792,458 meters per second, we just round it off to make basic calculations easier.  But we need to know exactly how fast it is for a variety of reasons.  For instance, our GPS systems wouldn't work if we didn't know precisely how fast light travels, since the technology requires very exact calculations of signal transmission times to determine your position.  Our understanding of light is essential to our use of radios, computers, and communications satellites (to name just a few).  The speed of light was first measured in the 1600s, and by the 20th century we were able to measure it with astonishing accuracy.  Meanwhile, independent evidence supporting our calculation of light speed is abundant.  The communications delay with the Apollo astronauts, and our robotic interplanetary spacecraft, is consistent with our understanding of the speed of light, and we have even used it to measure the precise distance to the Moon using a laser and a mirror left on the surface in 1969.

2. If you believe in the speed of light, then, do you believe that the stars and galaxies are very far away, or are they much closer than scientists maintain?
Measuring the distances to the stars is a complicated problem, but astronomers have come up with a number of clever ways to do it.  The stars have been found to be many light years away, and observations have demonstrated that our Milky Way Galaxy is about 100,000 light years in diameter.  But if we are to believe in the Young-Earth cosmology, we would only be able to see a small number of nearby stars.  For anything farther than 6,000 light years, there would not have been enough time in the age of the Universe for the light to reach us.  We would not be able to see even a single galaxy outside of our own (the closest of which is 25,000 light years away).  As it turns out, though, we can see very many galaxies.  Most of them are millions or even billions of light years away.

3. If you believe the stars and galaxies are much closer, do you believe in gravity?
Let's imagine for a moment our calculations of the distances to the stars are way off, so that they are much closer than typical estimates.  What are the implications?  Well, the Universe would be a much more crowded place.  Let's say the Milky Way galaxy is a mere 5,000 light years across, instead of 100,000 light years as we have said.  Astronomers have calculated the number of stars in the Milky Way to be in the hundreds of billions.  With a hypothetical Milky Way 1/20th the size, the volume is only about 0.0124% that of the original, meaning the stars would have to be a whole lot closer together.  And such a crowded galaxy would certainly complicate things as the mutual gravity of the stars would be much stronger.  In this model, using the current star count, stars are on average only 0.2 light years apart, so we could say that Alpha Centauri, the closest star system to the Sun at 4.37 light years away, might now only be about 1/5th of a light year away, much closer to the Sun than the theoretical Oort Cloud of Comets.*  It's easy to see how such a situation would radically alter the dynamics of our otherwise peaceful solar system.  But it could not be reconciled with observation.  Parallax would show that Alpha Centauri is clearly not this close, and the same would go for all of the other nearby stars, so we would have to say that the stars in our immediate vicinity are far apart as we have observed, but they are incredibly bunched up everywhere else.  Of course, there is no good reason why this should be the case.  The observed stellar motions about the galactic center just cannot be squared with this cosmology.  Our current star count would have to be wildly inaccurate, or our measurement of stellar masses would have to be way off.  But based on what we know about stellar mechanics, we cannot just reduce the masses of the stars without noticeable consequences, so this doesn't explain it. Otherwise, we would have to be living in an incredibly dense little galaxy.  But this just does not match observations. In addition, this sort of hypothesis cannot come close to accounting for the enormous number of galaxies we have observed, which would all have to be within our 6,000 year light horizon if we are to see them.  If everything we see beyond the Milky Way is within 6,000 light years, the galaxies would have to be incredibly small (much too small to be considered galaxies), dangerously close together, and their measured redshift could not be explained.++

4. Do you believe in radioactive decay?  If not, why not? 
One key way scientists have been able to determine the age of the Earth is through the use of radiometric dating.  Remarkably, every elemental isotope has a predictable rate of radioactive decay, which means we can look at any material and determine its age based on the decay of its constituent nuclides.  Using this method, scientists have found the oldest rocks on Earth to be over 4 billion years old.  Radiometric dating has also been used on rocks from the Moon, and meteorites recovered on Earth, and the results have consistently pointed to a Solar System in the vicinity of 4.5 billion years old.  Studies of orbital mechanics and the evolution of our Sun also corroborate this estimate.  Meanwhile, our understanding of radioactivity is central to modern chemistry and critical to the production of nuclear weapons and nuclear energy, so it's unlikely that we would be able to pull off such complex feats without a clear sense of radioactivity's basic mechanism. 

5. In short, do you believe in science?
After just a brief exploration of some of the problems with a Young-Earth cosmology, it's easy to see just how many backflips are required to square such assertions with the facts.  In order to prove a Young-Earth hypothesis, we couldn't just disprove one of the aforementioned scientific findings; we'd really have to disprove them all.  And unfortunately for the creationists, this is really a tall order (you'll notice, I haven't even addressed perhaps the most elegant evidence of Earth's ancient history -- evolution -- which they dismiss out of hand).  What science deniers don't seem to understand is that every single assertion in science has to be tested if it is to be counted as fact.  We didn't simply take Newton's word on it that gravity works the way he said it does.  It was tested, and it has been demonstrated to be correct.  The same is true of Einstein's mind-boggling prediction that time dilates at relativistic speeds: it's been demonstrated.  And down the line we go... every minor scientific detail, down to the most esoteric and obscure, has been worked out -- proposed, tested, and critiqued.  And there is extra scrutiny reserved for the explanations of phenomena that we cannot actually see with our own eyes, whether we're talking about quantum mechanics, astronomy, cosmology or geology.  Creationists like to insinuate that scientists are just making up their facts as they go along, but that accusation really betrays them; they are the ones with the unsubstantiated claims, and they are clearly unaware of the rigor with which ideas must be tested before they become mainstream theory.  Scientists don't have the luxury of simply inventing their own version of history, so it has taken centuries, and the life's work of countless scientists, to reach our present understanding of the world. 

In watching Richard Dawkins' fascinating interview with creationist Wendy Wright, one gets the sense that perhaps creationists may really just lack a clear notion of what "scientific evidence" means.  They are apparently unconvinced by the massive amount of empirical evidence to support our modern understanding of the Universe, but they are perfectly willing to take a single text written thousands of years ago as an infallible history of the world, and manipulate their science to match a predetermined cosmology.  Unfortunately, it seems clear that there is a major misinformation campaign underway, whereby legitimate science education is stifled or questioned, and a nonsensical alternative is presented as fact.  The Creation Museum and now Ark Encounter are tools in this vein, and insomuch as they undermine science education and poison the minds of the next generation, they are undeserving of public funding.
*Let's use this math as a jumping off point...  Using a crude calculation (volume of a cylinder = Pi * r^2 * h), we estimate the volume of the real Milky Way to be about 23.6 trillion cubic light years (radius is 50,000 light years, average height is 3000 light years).  Estimates place the number of stars in the Milky Way somewhere between 200 and 400 billion, so taking the average (300 billion), we divide that into the total volume and get the average volume surrounding each individual star, equaling 78.7 cubic light years.  Taking the cube root, we get 4.3 light years as our average distance between the stars (remarkably close to the actual distance from our Sun to Alpha Centauri).  But now we calculate the volume of our hypothetical Milky Way galaxy with a diameter of 5,000 light years and an average height of 150 light years (1/20th the size of the real thing).  With these values, the volume comes out to be 2.95 x 10^9 cubic light years (0.0124% of the real thing).  Dividing this by 300 billion, we get a average volume surrounding each star of only 0.0098 cubic light years, and the cube root of that is about 0.2 light years. 

++ Note: This hypothetically miniature Milky Way is not part of creationist doctrine, so far as I know.  I’ve just discussed it here as a thought experiment, to explore how the galaxy might have to appear to us if we are to take some ideas to their logical, if absurd, conclusions.  A number of alternative theories have been put forth by Young-Earth creationists, however: They have placed the Milky Way at the center of the Universe, to explain the apparent redshift of distant galaxies; they have proposed that our section of the Universe is under the influence of a white hole, so that time has been distorted in such a way that what has been experienced as 6,000 years here on Earth has been equivalent to billions of years elsewhere in the Universe; and they have suggested that perhaps the starlight we see in the sky was actually already in motion when the Universe was created, so even phenomena we witness in our own time, like a supernova we saw last week that is estimated by astronomers to have exploded 100,000 years ago, were actually set in motion by God 6,000 years ago, and they have just been designed to seem like ancient events (this last one is a particularly troubling and altogether ironic theory, since it means that God is deliberately deceiving us here on Earth to make us think that the Universe is old, when really it’s young.  What a trickster!).  These theories are put together by fringe scientists, in the employ of creationist organizations, and clearly they are designed to support a particular ideological conclusion.  But they are a clever bunch; by talking about white holes, redshifts, and the speed of light, their arguments sound very scientific, and to a casual or pious audience, that’s good enough.


  1. Why not build the "Ark Encounter" theme park. After all Disney's been peddling fantasy for 60 odd years and no one's grumbled.

    However, I do fear for the USA. If its debt doesn't sink it its gullibility will.

  2. The difference is that Disney doesn't portray Mickey Mouse or Captain Hook as representing literal truth. Walt created nothing more than a storybook while "Ark Encounter" is trying to make a statement of fact. And I don't think Disney is looking for taxpayer support either.

    Interesting post.

  3. American religiosity has to be one of the most fascinating mysteries of the world. With advanced societies getting ever more secular, why does the US get ever more religious?

  4. A very interesting post (I'm happy I live in Europe and not have to put up with creacionism), though I'm an evangelic christian.

    Merry Christmas

  5. I find that it's hard to engage a creationist in scientific debate. Their mind's are so firmly closed that there is no room for proper consideration of the facts!
    Bazza’s Blog ‘To Discover Ice’