|MadSci Network: Evolution|
What a neat thing to ask about. I was much older than you when I even first heard of carbon dating, so I think your curiousity is wonderful. You have two questions, one about your discovery of bones, and the other is about carbon dating. Let's talk about the carbon first. Carbon dating, as you seem to know, is a way we can get a rough estimate of how old something is that was once alive. Most of the carbon around us, (And in us) is regular, ordinary carbon, but a small percentage is exactly what you mentioned, carbon 14. Carbon 14 is formed in the atmosphere at a very constant rate over time, and like regular carbon it gets put into growing things, such as trees, animals, and people. When they die, they stop growing and so, no more carbon 14 gets into them. Carbon 14 is different than regular carbon because it is radioactive. And radioactive things have half-lives, which means that after 1 half life, you will only have half of what you started with. For example, carbon 14 has a half life of about 5730 years, so after this much time, there is half as much carbon 14 as you started with. In carbon dating, we can count how much carbon is left in an old bone, and count the number of half-lives it took and we can get an idea of how old it was when it died. If a mummy is found that had one half life of carbon 14 gone, we would know that they died about 5730 years ago. This only works on stuff less than about 50,000 years old because after that there isn't enough carbon 14 to count anymore. So, this does not work very well for dinosaur bones, for example because they are millions of years old. As for your bones, I think they are probably not too old, because you are right, the ocean does make things look old, and this means that water also makes things rot and break down quickly too, unless the bones were washed from rock by the ocean and then they came to your shore. I think a good place to try and find out what they are would be to look at books that have lots of pictures of animal bones in them, you might find something that matches. If you still cannot figure it out, I would go to a school and ask a biology teacher, or to a University and ask a zoology or biology professor if they can take a look. What a great find, I think they could be anything, a fish, maybe a cow, a dolphin, or monkey... Or who knows, maybe even a dinosaur. Happy hunting.
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