One thing that scientists of today and Calvinists seem to have in common is an antagonism towards philosophy.
Scientists believe that philosophy at best is a way station on the way towards a more complete knowledge of our universe which can only be achieved through the scientific method.
Calvinists believe that philosophy is sheer hubris on the part of finite humans to attempt to understand the workings of the mind of an infinite God.
Attempting to get a scientist or Calvinist to engage in a philosophical discussion with you on free will is pointless.
Scientists will refer you to the latest texts on neuroscience, expect you to read them thoroughly, and then limit your discussion to purely materialistic speculations.
Calvinists will expect you to limit your reading to the Bible and those approved interpreters thereof.
If you are truly interested in a more philosophical approach to this question then I think you should start here:
This particular entry was written by a Christian philosopher . I don't know if she personally is a Calvinist or an Arminian or a Molinist, but she makes a good, though not compelling, philosophical case for the Calvinist position.
I think you will find a lot of other articles of interest at this site that discuss Free Will, Predestination, Materialism, etc. Very few entries claim to have solved any of these philosophical problems. However, they do help you to understand the terminology, the issues, the possible answers, and the overall complexity of the issues involved and why there haven't been any simple answers so far.
My own belief is that philosophy is still a very useful endeavor. I don't think that philosophy will ever be replaced by science. I don't think that it is a form of hubris for humans to use their God-given talents to try and better understand the human condition.
Daniel Dennett has written extensively on the concept of Free Will. He believes that there is still room in a purely materialistic universe for humans to have free will. His arguments have not been particularly convincing to either philosophers or scientists. He claims to be a philosopher, but I believe that like Patricia Churchland he is someone who started out as a philosopher, but now believes that science holds all the answers and that philosophy is just bunkum. Still, he might also be a good person to read to get an idea of the mind of the modern scientist.
If a scientist is being honest, he will have to tell you that he can't be absolutely certain of anything. Since the scientific method begins with empirical evidence, and all empirical evidence is limited, no absolute statements can be made. The best they can argue is that there is a really, really good chance that the models they've come up with can predict some very well-defined future events if every one of the important starting conditions is well-understood and controlled for.
Good luck with the Calvinists. There are certain things they know for sure, and other things they know are beyond all human understanding. And they also somehow know which things fall into which category.
It would seem foolish of us to assume that the Lord does not have access to more facets of the creation than we do.
Problems with sovereignty statements about God occur when we insist that we know that God’s sovereignty is wooden, that it even forces His own hand in all circumstances and leaves no room for any meaningful love or heart. I.e. when they state that God has no choice but to make us puppets in every manner.
That is not how love works, however. There is always an element of respect in love.