5 -- The Age of Our World Made Easy

In the 17th century, a theologian called James Ussher worked out the age of the universe based on the chronology of the Bible. It was created, he concluded, in a week in October 4004 B.C. Even today, millions of people still believe that this 17th century calculation is about right, and that the overwhelming evidence of geology, cosmology, paleontology, chemistry, astrophysics, geophysics, stratigraphy, and biology is wrong.

So lets take a look at what that evidence is, starting with a principle that even creationists don't dispute. The golden rule is that newer sedimentary deposits are always laid on top of older ones, so accept that where rocks have been folded, this orange bed would be older than the green one, and the green one is older than the blue one. Geologists can then follow a single bed to make similar deductions in a different locality. The dark grey bed may be at the surface, or even at a higher point than the others, but its older than all of them, and the light grey bed is older still. What we end up with is what's called The Geological Column. To get the absolute dates of these rocks, scientists use a variety of different methods. I'll start with one of the easiest and most recent.

We all know trees have rings, because in summer they grow faster than in winter, but seasonal growing conditions vary according to the weather, so the bands will vary in size. Each time period in each geographical location has its own distinctive patter of tree rings--like a fingerprint. So if we take wood of a known age, we can match the oldest part of it with the youngest part of another piece of wood, and so on back through time. Back 10,000 years, in fact, and already way beyond the biblical chronology.

Okay, Ill spend a bit of time on this one, because creationist preachers seem to be obsessed with it. Our upper atmosphere is constantly being bombarded by radiation from the Sun. When a stray neutron hits a nitrogen atom, it changes it into carbon, but this is a heavy and unstable form of carbon called carbon 14, or C14. The normal form of carbon is C12. In the atmosphere, C14 combines with oxygen to make carbon dioxide, which is then absorbed by plants and into the bodies of animals that eat the plants. The ratio of these two isotopes in animals and plants is roughly the same as the atmosphere around them, but when the animal or plant dies, C14 decays over time, and reverts back to nitrogen. So compared to C12, which doesnt change, the amount of C14 falls at a constant, measurable rate. By measuring this ratio inside the dead animal or plant, scientists can find out when it died.

Before I look at other dating techniques, I'll bat a few hoary ole myths about carbon 14 out of the ballpark.

(Text on screen: Carbon dating is inaccurate)

No, it's not. But sometime, rarely, a sample is wrongly dated, because it's contaminated. Bacteria, dead skin, fungus—if care isn't taken, it's the carbon in these contaminants that gets dated rather than the sample itself. That's why samples from different parts of the same plant or animal have been known to give different results. But a similar thing can happen with any kind of sampling. Contaminated samples don't invalidate the principle of DNA analysis or chromatography or spectroscopy. We know they work, and we know carbon dating works. Firstly, carbon dating can be checked against artifacts of known age. Secondly, it can be checked by sending the same artifact to different labs for analysis. Thirdly, let's take a sample of organic material from each of these layers. If carbon dating were random nonsense, you'd expect that the chronological order of these samples to be all over the place, but that doesn't happen.

The results show each of these samples in its correct chronological order. The ones from the upper beds are younger, and the ones from the lower beds are older. Is it magic, or is it because carbon dating works, and that's why it's used?

To quote Kent Hovind, Samples don't come with labels attached telling the lab their age. Testing is always blind. If its not blind, it's not science, and if creationists don't trust the carbon dating method, they're perfectly welcome to conduct their own blind test to prove it wrong.

But carbon dating isn't used on diamonds and coal, and for very good reason. As I explained, C14 is formed when neutrons collide with nitrogen atoms. The C14 used in carbon dating originated in the atmosphere, but you can also get it deep underground in places where decaying uranium is giving off neutrons. Coal and diamonds are made of carbon, so you'd expect to find higher levels of C14 in coal and diamonds close to rocks that contain uranium, and much lower levels away from those rocks. That's exactly what we do find. Carbon dating is only used and only useful for dating organic material in the topmost sedimentary layers.

Now that weve got carbon dating out of the way, let's quickly run through a few more absolute dating methods.
Biologists know that human DNA mutates at a fairly regular rate, and they can trace these mutations back. Like following the branches of a tree back to the trunk, it's not a greatly accurate method, but it does give a rough idea of when humans migrated and a very definite idea of where. It doesn't lead back to Mt. Ararat 4000 years ago, but to Africa around 50,000 years ago, just as other dating methods suggested it should.

Every 250 thousand years or-so, the Earths magnetic fields flip over, and the South Pole becomes the North Pole. Magnetized minerals within rocks show the polarity of the Earth when the rocks were laid down, so throughout the geological column, rocks show a regular magnetic banding depending on the polarity of the Earth, and that can be dated.

Potassium-argon dating works on the same principle as carbon dating, but instead of carbon decaying to nitrogen, we have potassium decaying to argon, and instead of a half-life of 5500 years, we have a half-life of 1.3 billion years. That means the method can be used for dating rocks and fossils hundreds of millions of years old. The technique is largely being replaced with the far more accurate argon-argon method, and there are other decay processes that can be measured, each with different half-lives, such as uranium-thorium and rubidium-strontium. Radiometric dating takes us back to the oldest rocks we found on Earth, 3.8 billions years old. If you want to go back even further, you have to look into space.

My video, The History of the Universe Made Easy, explains how we can calculate the age of stars and galaxies, so I won't repeat that here. Just take a look at the video. What's important is that the results fit perfectly with the chronology we find on Earth. The Sun, for example, doesn't turn out to be younger than the Earth or older than the universe. Its age, based on the amount of hydrogen fused into helium, is exactly what youd expect. As with dating methods devised for rocks on Earth, the method for measuring the age of stars and galaxies is devised first and tested afterwards. There's no way of knowing in advance what age these tests will show, but every time, the age confirms the known chronology of our world.

As technology expands, new dating techniques are constantly being developed. If the world really was around 6000 years old, you'd expect them to show it, or at least disprove the established chronology. But they don't. Every new technique confirms what we know.

There's thermoluminescence that can measure the number of trapped electrons on the surface of volcanic rock. The speed that continents are drifting can be measured today, so their position millions of years ago can be calculated. It matches perfectly with the geological chronology we've already worked out. Climatic banding in sedimentary rocks can be measured, caused by a wobble in the Earths motion every 12,000 years. I could go on, but there's no time here to list every dating method, let alone spell out the details of how they work. But if creationist preachers are so convinced every single dating method is wrong, and that the single story they tell is the result of either a huge coincidence or a giant conspiracy, it's very easy for them to prove it.

After all, a few creationists have university degrees in biology and geology. Okay, then, devise a dating technique of your own choosing. Explain publicly how it works. Have it tested against samples whose age we all agree on, so we know it works. Then go out and take samples of sedimentary rocks throughout the geological column, and have them tested by the method you devised.

Not surprisingly, not one of the so-called creation science organizations has bothered to do this. Why not? If the Bible is right, then all the samples would date to around 4000 years ago and provide strong evidence that the biblical flood was real. But if the Bible is wrong, then the dates will be much older, and more importantly, the chronological order of the samples will be in perfect accord with the comparative ages of the geological column.

For some reason, so-called creation scientists, despite their professed faith that the Bible is right, don't think that's a risk worth taking.