Read some articles about the evidence for life on mars from the martian meteorite.

Notice that the investigators say only that their claim is not obviously wrong and challenge others to prove them wrong. Others rose to the challenge and it is now generally believed that the claim was indeed wrong.

DNA evidence, for example, compares a suspect's DNA to that found at a crime scene. However, the lab can only perform a small number of comparisons, which cannot prove that the DNA is identical. Thus, it is difficult to get a conviction based on DNA evidence.

Scientific evidence is always circumstantial.


In this class, you will be learning some laws that have stood up to every test for over 400 years.

Are we positive that these laws are correct? --- No.

Would you bet that they are wrong? --- Only if you like losing bets.

When a well-tested scientific theory is proven "wrong" it usually does not just go away. All of its correct predictions remain and we usually go right on using it, but with an understanding of when it does and does not work.