Thank you "punos" for your thoughtful reply. I am not a physicist, so please excuse my ignorance. Why would a proton be affected by other particles in a 5 light seconds radius? Surely, the zone of being affected would be mere millimetres or even less?

Thank you for your thoughtful reply. I find uncertainty difficult but I have no way to be certain of anything except for one fact: I am conscious. I am 99.99% certain that I will die but I can't be 100% certain of it until I have died. If it was up to me, all living things would be forever happy and there would not be any suffering, inequality, injustice, and deaths. Sadly, it is not up to me.

Thank you for watching the video and for sharing your thought about it. You can watch the full video here if you want to https://www.youtube.com/watch?v=nhvAAvwS-UA&t=135s

You are most welcome "Corvus." If souls exist, it is possible that souls reincarnate or resurrect after death of the body. I don't know if souls exist or not.

Thank you "Corvus" for your reply. I am 99.99% certain that I will die but I can't be 100% certain of it until I have died. If it was up to me, all living things would be forever happy and there would not be any suffering, inequality, injustice, and deaths. Sadly, it is not up to me. How would I know if others really exist? How would I know if others are really conscious or are actually philosophical zombies?

Thank you for your reply "Art48." I am 100% certain that I am conscious. No infinite regress is involved with this. Did you watch the Robert Sapolsky video excerpt? If so, what do you think?

Thank you "Tom Storm" and "Philosophism" for your replies. You have given me much to think about. So, is my perceived reality actually real or not? Do I have free will or not? Am I right to be a vegan or not? Am I right to be an agnostic or not? How would I know? This video: https://www.youtube.com/watch?v=uaxHTYtSavc is fascinating. Is Robert Sapolsky right?

Thank you for your reply "Outlander." It is more accurate to say, "Like minds think alike." It is the fact that they think alike that makes their minds alike.

Thank you for your reply "flannel jesus." How would I calculate what percentage of certainty I assign to things such as the objective existence of my body, other humans, non-human organisms, the Earth and the rest of the universe?