Q: Is there any scientific proof that after life, there is no heaven or hell?
A: There is and cannot possibly be any scientific proof that there is or is not a heaven or hell, or even that there is or is not an afterlife.
Science is empirical. All scientific knowledge relies on/derives from physical observations. The afterlife is presumably nonphysical, since it s where whatever s left of you goes after the physical body dies. And it s a personal and therefore subjective experience, as it s only the individual that goes into the afterlife, and personal and subjective experiences don t count as proof in science.
You could argue that the afterlife is more than just personal and subjective since it s supposedly a single reality shared by many souls interacting with each other (or maybe many such realities), but still, what re you gonna do, send a machine/probe with scientific instruments into the afterlife? That would seem clearly impossible.
A lot of people believe that the afterlife is impossible because science shows us that cognitive abilities, emotions, memories, and other aspects of mind, as well as the presence or lack of consciousness (at least as far as it can be indirectly observed), can all be manipulated in detail by physically affecting the brain, and therefore consciousness and mind must be products or processes of brain processes. I saw one person claim that in the answers to this question.
But it doesn t really prove that consciousness and mind are dependent on brain processes. There s no way to prove that, since consciousness and mind aren t directly, physically observable you can only measure them by observing the outward behavior of the subject. That s not to say that it s not likely an accurate indication of what s going on in the subject s mind, but that you can t show that their consciousness or mind is wholly made up of material processes.
The possibility remains that the consciousness and mind are somehow fused with the brain and body while incarnated, then are again decoupled upon death. And there s good reason to make such an assumption, if you take into account myriad near-death experiences. I recommend, for example, watching the documentary After Death .
People assume that near-death experiences are merely wish fulfillment and hallucinations brought on by DMT released in the brain and oxygen deprivation, but that doesn t make a lot of sense because near-death experiences aren t like typical experiences on psychoactive drugs including DMT, and it would be very coincidental that the particular wish fulfillments (like seeing and hearing your loved ones who have passed on reaching out to you while you re dying, or rising up from your body and seeing yourself and your surroundings from above) are exactly what would make sense if there were an afterlife. And there are many common elements to NDEs that there s no apparent reason for if it s merely wish fulfillment and hallucinations, such as the life review and going toward a bright light at the end of a tunnel, just to name two. And the afterlife is always experienced as being even more real than real, while you d expect them to seem less real and coherent than normal life if they were merely hallucinations. And there have been some documented NDEs that were impossible under physicalist assumptions, such as people having had experiences in the hospital while the necessary brain processes were offline, including having heard and seen things that happened on the operating table that they couldn t have known. One such case is explored in After Death .
And another good reason to make the aforementioned assumption is cases of people remembering past-life situations and events that were later verified that they had no way of knowing. There are a few such strong cases, one of them being the case of James Leinenger. There s a video about it here
which doesn t even cover all of the evidence.
There are also tons of stories of kids talking to and knowing details about deceased people, such as relatives and past inhabitants of the house, that they couldn t have known. Skeptics out-of-hand dismiss all such stories as anecdotal evidence, but that s too easy, dismissive and self-insulating.
I also have some arguments as to why it s unlikely or impossible that consciousness or mind could arise from brain processes here: