Originally posted by Dr.Fox
There are 6 billion humans, More animals , More gases etc I think its heavier !
Thats completely irrelevant. Humans, animals, and anything else that grows start from nutrients. We use nutrients to grow. Thing such as proteins and calories in the foods we eat. The gases do not just magically appear. Everything goes through a cycle. One way we get more gases is by drilling for fossil fuels and then processing them. Another example of more gases being released would be a volcano erupting. Life on the planet has absolutely no influence on the planet's weight or mass. Anyone who believes that needs to pick a up a book and learn a little
As far as the original question goes, I believe its much heavier than 4 billion years ago. There is actually an active study on how much meteoric dust settles on earth every year. They estimate that the planet collects over 30,000 tons of meteoric dust annually!
Some people said that is lighter because of the satelites we send into space. Thats like saying if you remove an ant from your house you made it light, when in reality, you probably tracked enough dirt inside in the process to double the ant's weight.
If any of you are interested in physics and cosmic studies i would suggest reading Stephen Hawking's books. They're really in debt on this subject matter.