Our modern "science" is adept at dealing with the physical world, but no so good at dealing with spiritual matters. Quantum physics is making some inroads, however.

In a court of law the jury is not presented with "proof" of a crime, but rather "evidence". If the evidence is compelling it is accepted as "fact" and a verdict is rendered accordingly. This isn't "science" but it is logical.

There really is a great deal of research taking place, done by respected and reputable people. I encourage you to read a book by Dr Michael Newton, PhD entitled "Journey of Souls". You can get it at Barnes & Noble bookstore and is available in eBook format if you have a Nook. This single book will address all your questions and more.