- Wonder about something in the world.
- Make a guess about what you think it is.
- Test the guess.
- Make conclusions based on the outcome of the test.
- Wonder about something that happened in the past.
- Make a guess about what you think happened.
- Collect evidence.
- Make conclusions about the evidence.
Do you see the differences? In observational science we do tests here in the present that can be repeated and verified. These tests lead to cures to diseases, computers, vehicles, and men on the moon. In historical science we can only collect evidence left over from the past and make conclusions. These conclusions are essentially unverifiable.
Real world example: observational science gives us natural selection within species. We see it all the time. We can repeat it and test it. Historical science then takes that evidence and makes an unverifiable conclusion about the past that this process has led to changes from species to species.
The study of creation and evolution both fall under historical science. Neither of the conclusions surrounding those can be verified. Creationists feel they have the upper hand because they are including information revealed by the only one who was there through all of history that never lies.
Historical scientists will always make their conclusions about the evidence based on their starting condition: either the supernatural exists and God intervenes in the world OR only the natural world exists. So the debate does not come down to evidence. It comes down to interpretation, and if the supernatural exists or not.
If the supernatural exists, the creationist’s conclusions are just as valid. A Christian has no reason to accept a natural-only interpretation of our origins. No natural-only explanation can EVER disprove a supernatural one. Since historical science is all unverifiable assumptions, I see it best to trust the explanation of one who was there who never lies.
Check out this video for more info on the differences between observational and historical science: