Hair Detectives

The article talks about a new method to know where people have been because of their hair.
Our body is full of hydrogen and oxygen, and this elements end up in our tissues, and hair.
But as not all atoms are the same, they vary in how much they weigh. Different forms of a single element are called isotopes. And depending on where you live, tap water contains unique proportions of the heavier and lighter isotopes of hydrogen and oxygen.
Scientists made tests, they went to a barbe shop and collect hair from different people, they check it and realized that they all lived in the same area, so this metod works, not every time because water in different places can be the same, but this might help a lot in the future to know about crimes, and different types of stuff.

What I think about this article is that it's such a good way to find out where people have been and figure out about crimes, maybe not to find out who was the person that did the crime, but to be close, to know where he or she was and it might help a lot.
Or maybe it can't work all the time because the water, as they say can be the same in many different places or maybe the people just drink imported water, but who knows.
But it is really impresive to know that science is so advance and that by looking at your hair scientists can know where have you been and where are you from and maybe in some day in the near future they can know who were your great great great great great grandparents.
I would like to know more about this kind of stuff.