Hi! did you get your answer or no if not I have it if you are interested. Have a nice day! ;)
Are you looking for projects like experiments?
Answer:
Index Fossils
Explanation:
Index fossils are used by scientists to help them figure out the dating of discovered fossils or the correlation. They are also very known to appear in a (very) certain/specific age range.
Hope this Helps!
No they cant be mechanical because then something would have to generate their rays through the inventing of a machine.
