I was trying to convey a message to him that nothing is final in the world of science the earth was considered flat once now we know its not we cant just ditch scientific process cuz of this
Actually, the earth being flat was not a conclusion that was arrived at through the scientific process. It was a dogmatic belief of Europeans in the dark ages.
(By the way, people millenia before knew that the earth was round. Eratosthenes even measured the radius of curvature with a painstaking experiment, sometime in the 3rd century BC. Anybody who observes a ship sailing into the distance can understand that the earth is curved. And there was plenty of intercontinental sea trade millenia ago.)
Also, your statement that since science may have been wrong, it will keep changing is really a misunderstanding on your part about "wrong" and "right". True, Science keeps discovering more, and maybe even revising previously held beliefs. But that doesn't mean that the previous beliefs were WRONG, just that our understanding is getting more refined.
For example, Newton's laws of motion are right (more or less). But Einstein showed that it is right mostly in our experience, and that in different conditions, those laws would have to be modified. Scientists didn't replace the old theory with a new one, it just meant that a deeper understanding was arrived at.
You could say that "Einstein proved Newton wrong". But Newton's laws of motion are still used for most everyday phenomena. It is not wrong becoming right, but us getting a more refined understanding. As I mentioned before, once scientists thought that electricity and magnetism are different phenomena; by the 19th century, they were shown to be the same thing. That doesn't mean they were wrong per se, but just that they refined their knowledge of electromagnetism. The electrical and magnetic devices they invented previously, still functioned.
It is VERY RARE in the sciences, that something that was thought to be true through the scientific method is then shown to be WRONG. I can't think of any such instances. But theories do get refined and sharpened.
Maybe there are a few examples of scientifically determined knowledge being proved completely wrong. I can't think of any.
This is an essay by Asimov that should explain what I'm trying to say:
Asimov - The Relativity of Wrong