Stromatolites grow at a maximum rate of 5cm every 100 years and a stromatolite 1.5 meters in diameter was found in Virginia and a 500cm high stromatolite was found at the foot of Wutai Mountain in China.
Take a quantity of uranium-238 and in 4.5 billion years half of it will have turned into lead-206.When molten rock hardens into a solid, the uranium-238 within it begins to decay.When a species gets split into two groups by a river, mountain range, island, lake, or ocean via earthquakes, floods, droughts, climate change, or continental drift, the two populations will begin to drift genetically.Mutations that reduce an organism’s ability to survive and reproduce will be less likely to end up in offspring.By comparing the ratio of uranium-238 to lead-206, we can estimate how old the rock is.
The same thing can be done with Samarium-neodymium, Potassium-argon, Rubidium-strontium, and Uranium-thorium transitions. There is a semi-constant ratio of carbon-14 in the air and ocean as it is constantly being created by cosmic rays.
Please feel free to refine this list and repost it, just please preserve the photo credits and links to photographers.
Also, suggestions for improvement on any items is welcome as this is a lot of material over a wide range of scientific fields, so I have certainly bungled some things here.
I’ve used links to articles in Wikipedia as much as possible because Wiki articles are refined over time with our understanding of the subjectmatter and are less subject to link-rot.
This post is licensed Creative Commons and all photos listed here are available under some form of free-to-use licensing.
because science is about refining our understanding of the truth.