Some Christians believe the world is about 6,000 years old, in accordance with the creation doctrine outlined in the Bible.These people are wrong.
The world is actually about four and a half billion years old.
Why do I believe this?
Well, I'm not scientist - but if I go to a museum, I can see rocks that are 3.9 billion years old. Some of these rocks contain minerals that are up to 4.2 billion years old.
If the Earth consists of rocks that are over four billion years old, the Earth itself must be at least that old.
But how do we know how old these rocks are?
Through a system called 'radiometric dating.'
Although the science of radiometric dating is very complicated, the concept of it isn't. It's based around measuring how much the radioactive isotopes in the object being dated have decayed.
The principle's much like a candle: Take a ten inch high candle made of wax. If you light that candle and leave it for an hour, it will burn one inch of wax in that time.
Therefore, if you opened a door and found and same type of candle burning, but seven inches of it were melted, you'd know that it had been burning for seven hours.
With radiometric dating, you take a rock and measure how much of the radioactive isotope within it has decayed. Based on the rate that type of radioactive isotope normally decays, you can work out the approximate age of the rock based on the result.
Scientists have found minerals on the Earth that they can prove, conclusively, are 4.2 billion years old. Therefore, the world is at least that old.
B-b-but....?
Some Christians argue that the world is not four and a half billion years old. It's actually six thousand years old, like the Bible said.
They have two common theories to 'support' this:
1: Radiometric dating is inaccurate. Since the science doesn't support their belief, the science must be wrong. This is a fine theory, except it's not true and isn't based on any factual evidence whatsoever. Just because you don't like something doesn't mean you can make it 'not true' by refusing to accept it.
Radiometric dating is just as real and observable as the wax candle I mentioned. We know that this hypothetical candle burns down one inch in one hour. Therefore, if it had burnt down seven inches, it must have been lit seven hours earlier. If you can explain how that candle could have burnt any faster (yet keep your answer within the boundaries of scripture) you might have a shot at convincing me about radiometric dating.
2: God created the Earth 'as is.' Some Christians argue that God did create the world six thousand years ago - except he created it to appear as if it was four and a half billion years old. That's a fine theory too, except it trips up.
First off, if God exists, WHY did he make the world appear older than it was?
Secondly, if God had the power to create an 'already old' world six thousand years ago, how do we know he didn't create the world (and all our memories) five seconds ago? Like the best irrational theories, this one can be neither proven nor disproved - but ultimately belongs more in the realms of philosophy than science.
Conclusion
The only rational conclusion, based on the evidence, is that the world has to be at least over four billion years old.
