We have mapped some of the brain but nobody knows where consciousness comes from. The bit that makes "us". We have absolutely no idea. There are different theories swimming round but consciousness is still one of the great mysteries.
If you don't believe me, type into google "where does consciousness come from?"
Scientists suspect it does come from the brain although they don't know which part, it's hard to move on to prove this because no one knows how to define consciousness from an objective, third person perspective. We only have access to one consciousness and that is our own.
Hawking refers to humans as computers quite a fair bit but I don't think it's a good analogy. I know my iPhone doesn't have feelings or a personality. If we are nothing but computers, surely we would come across people in our lives with identical personalities to our own? How can it be that we are all so different. Why do I hate bananas but my daughter loves them? Why does she hate mushrooms?
I guess the way I see it is metaphysical, maybe if we swap the word "spirit" for "conscience" and pose the question "does our conscience live on after we die?". If we remove the idea of faith and spirits, does the question sound less absurd?
I personally don't believe in God but I believe in some kind of energy moving onwards. As a pp said above energy can't be destroyed only transferred.
We know so little about the Universe and have only touched the tip of the iceberg when it comes to physics, maybe we do live on but there is a scientific explanation for it?
Who decides our science and laws of physics are correct? There is a whole world of shit that we don't know and who wants to understand everything? I love pondering questions such as this. Gives life a little mystery.
If we had categorical proof of an afterlife and Heaven (or whatever) wouldn't people be killing themselves? What would be the motivation to overcome life's more troubling times?
Disclaimer: ^^ these are MY beliefs. I am not trying to force them on anybody and if you believe in nothing-ness after death then that is up to
. It's only natural Laws of Opposites that people believe in different things.