Well obviously things that have occurred in the deep past cannot be empirically observed. So there are certain assumptions that have to be made. You have to assume that the conditions that we see in the present were still working in the deep past in order to make a rational extrapolation backwards into the past. But obviously that is not always the case.
As to conditions in the past working the same as we observe them now, the fine tuning argument for God states that if the fundamental forces such as gravity were different by even a small amount, then life would not have been able to develop and persist, and the universe would not exist as we see it today. It's these fundamental forces that dictate how things work. Everyone agrees with the premise, but disagree as to why. So we have good reasons to think the universe in the past had the same strength of laws therefore behaviour as we have today.
The theory of evolution is a good example of the above situation.
As to looking back into the past, there are again very good reasons as to why we can do this. Every time you look at a star you are looking back into the past. In the case of the nearest, the sun, we are looking eight minutes into the past, in the case of the furthest observable stars, that's looking back 12.9 billion years ago. Spectroscopy can tell us about the elements within a star …
From spectral astronomers can determine not only the element, but the temperature and density of that element in the star. The spectral line also can tell us about any magnetic of the star. The width of the line can tell us how fast the material is moving. We can learn about winds in stars from this. If the lines shift back and forth we can learn that the star may be orbiting another star. We can estimate the mass and size of the star from this. If the lines grow and fade in strength we can learn about the physical changes in the star. Spectral information can also tell us about material around stars. This material may be falling onto the star from a doughnut-shaped disk around the star called an accretion disk. These disks often form around a neutron star or black hole. The light from the stuff between the stars allows astronomers to study the interstellar medium. This tells us what type of stuff fills the space between the stars. Space is not empty! There is lots of gas and dust between the stars. Spectroscopy is one of the fundamental tools which scientists use to study the Universe.
Found
here. So yes, we can look back into the past and glean information.
We do the same sort of thing with evolution. The following is a list of things that give us information about species from the past and therefore evolution …
Anatomy, molecular biology (DNA), biogeography, fossils, embryology, carbon dating etc etc, the list just goes on and on and the information from all of these diverse areas of study all point to the same conclusion, that evolution is real.
I was referring to theoretical science. In theoretical science most scientists think they should remain open to other possible conclusions. The earth orbiting the sun is empirical science.
There is no direct observation of the Earth orbiting the Sun. It had to be figured out theoretically from amongst other things, indirect observation.
No, you missed my point. In both cases neither one was seen empirically being created, so how do experts tell the difference between a rock shaped like a spearhead and an actual spearhead?
Rocks fashioned like spearheads don't occur in nature. What is your point?