When life on Earth began 6000 years ago humans lived for 800 years and stood 600 feet tall, but why?

Well the answer is simple, people lived longer because the air was much better back then and because they lived longer they had more time to grow. It was also important that humans were this size because of the dinosaurs. Dinosaurs were just really big birds and in scale with the humans of the time. The skeleton of a T Rex is exactly the same as a chicken only a lot bigger, an Apatosaurus was simply a big dog. So, you see...there were no dinosaurs just really big animals that were in scale with the humans of the time.

These facts have been proven by great professors such as Kent Hovind and Ken Ham.