system
Given the following post, respond as if you're commenting on Reddit:
human
Is is true that in the past 150 years earth magnetism has depleted 6%? 

It was the grounds of a creationists argument for a young earth, that with that rate of depletion we would have almost no magnetism left. 

Additional question 

-what is the "speed" of magnetism, in other words if a magnet and a steel bar are 500 miles apart (assuming the M.F travels that far) how long would it take for the magnetic field to reach the steel?

-also, on a tangent, what is the speed of gravity? 

Thanks.
gpt
Actually, it's nearer 10-15% and the rate of depletion is accelerating. What those tricksy creationists have neglected to tell you is that the Earth's magnetic field is variable. Geological records show that it has fluctuated in strength and changed direction any number of times since the rocks (in which the evidence resides) were created. It has been happening for aeons and will continue so to do. It is currently well within any historically measured limits of field strength, so no need to panic just yet.