The great breadths of time.

There's also just about no "assumption" left in the universe being very, very old. Distances to even nearby galaxies are huge - so far that their light takes millions of years to reach us. The actual distances have been measured, in some cases, by methods that depend only on geometry and on the Doppler Effect - the same one the traffic cop uses to give speeding tickets.And then there are distant galaxies that look just like nearby galaxies, but small and dim. Similar to how the cows over past that second fence look like these twelve feet away, but small (all cows seem pretty dim to me). Measurements of objects in these distant galaxies pretty much makes it 100% certain that they are billions of light years away, and that we're seeing them as they were billions of years ago.And welcome to the zoo, Gigahound!

Woohoo! I can now bore you all to tears with chemistry!Al₂(SO₄)₃!!!!!!

And a large rock does follow the same rules - a favorite of young-earth creationists is Lord Kelvin, who calculated cooling of the whole Earth using this sort of math back in the late 1800's. YEC's typically don't quote his minimum age of 20,000,000 years, though, for some reason.And, of course, radioactivity wasn't known of until 1896, so Kelvin couldn't have known that Earth has an internal heat source that slows his cooloff rates tremendously.

This heat difference is very well known in the oil industry - here in West Texas a 10,000 foot well will be about 160 Fahrenheit at the bottom; southeast of Dallas it would be nearly 300 degrees at that depth. The difference is largely due to different minerals below there and, I presume, to differing thickness of the crust. At Brawley, California it's more like 700 degrees at that depth, because the crust is thin over the rift that formed the Sea of Cortez - you're nearly drilling into a pluton, or the mantle.Edited by Coragyps, : add comment