There is no real science in this. I don’t discount people’s accounts but we know so little about how consciousness works that it is crazy to say any of that is proof. Kind of feels like it was paid for by some religious organization. My dad died unexpectedly and quickly just two years ago. It would be really easy to believe this stuff to talk to him again but that feels selfish to me. I can only hope that whatever happens after you die, you are at rest and not meandering around your loved ones watching them suffer with their grief and not being able to help.