Take two people for example, lets say Admiral Nelson, and the other, a man called William who never became famous or had so much as a word written about him, but lived in the same time period.

Now we remember Nelson because of history being written down, so we affirm a man called Nelson existed, and did this, this and this while he was alive, his existence is affirmed by our brains, so does that mean he is still a part of reality in some way? or not?

William on the other hand has never been heard of, yet he lived, was physical as Nelson was, had thoughts and memories, yet no-one remembers him, does that mean his existence is entirely erased from reality in a way that Nelson's is not? or does he too remain just as much a part of reality?

Once i die and i'm gone, is there any way other sentient beings could ever find out i had existed, if i left no trace of my existence? do you leave a trace in time just by existing, or are you erased completely, as if you had never been?

I guess the questions seem very confusing because they are entwined with each other, does being remembered mean you are still a part of reality? does being forgotten mean you never existed? can there ever be a way of finding out who or what lived when and where, if they are swallowed by the destruction of their own bodies, lost in time, when you stop living, do you stop being a part of reality completely and absolutely?

If you were to drop a key into the deepest, darkest ocean, there would still be the smallest of chances that it would one day be found, is proof of our existence like that key once we are gone, or are we erased utterly? If erased, it seems incredibly cruel, because proof of existence, even if we are long gone, would be a small triumph, a small consolation, that we were once here.

Look up the brain in a vat, or solipsism.

Like what if everything you were writing was just in my mind. Your ideas and your reality only existed because I do. Everything else is just a figment of my imagination.

Both of them are just as much part of reality as anyone else. Just by existing, even if it's as short as never making out of your mother's womb, you're effecting all kinds of things. Already, your existence has changed the reality of everyone you've ever interacted with had you not been there, and that can never be taken away. Just because some people die without ever being remembered by history in any way, shape, or form does not mean they did not have a substantial amount of contribution to reality as we know it.

If a tree falls in the forest, and no one is around to hear it, does it make a sound?

Does anything exist outside of our ability to perceive it?

Just because something is written down, does that mean it really happened? In five thousand years will a civilization pick up a Harry Potter book and learn of a whole society of witches and wizards who lived in secret alongside of us?

Hard to say because it's hard to verify.

A good addition to this point, take spies.

The ones you hear about are the ones who have FAILED. Without them, however, we wouldn't have retrieved vital intel in wars that could have changed the course of history.

Unless you subscribe to the idea that you're the only thing that's "real" in reality. In that case... the whole thing goes kaput when your brain finally switches off for the final time.

Is there something in the universe that can be read to discover it's history, as forensic scientists might read finger-prints? something that can be followed like a trail in time leading back to each and every last living organism? If not, and we are utterly swallowed into non-existence, does that mean the past and the future are not real?

Both Nelly and Will were a part of reality. That is IF Will existed as Will and not as "Bob" which he may also have been called; we can't know this. However we DO know that people existed during the life of the good old Admiral thus they are an anonymous part of reality as a whole. As for you, your existence is confirmed by the fact that you started this thread. All things considered this seems like a complicated reworking of the "if a tree falls in the forest..." schtick. What's with all the existentialist questions guys? Are you all depressed or something?

I want to know if one day we'l be able to deduce the past existence of individuals and even events, is there anything in the universe that might be able to be read? like some kind of super-advanced molecule reading to see where they've been, what objects they were once a part of, and paint a picture of the past by reading something like them? or is everything all hopelessy jumbled up in such a way to never be read again? and if so, does that mean the people of the past never actually existed? how can we prove they were there if we live reality in the present and nowhere else?

There is a void between us and the past if we cannot grope backwards in the dark, a true void, and the future is not yet made, so where are we? on this line of time, where the feck are we existing?

Yes.
No.

Oh well that's more of a scientific question than a philosophical one. Who knows? I doubt it will be possible in our life time.

I feel that even if there is no afterlife, to be able to prove that we were once there, to know that the universe kept some kind of a record of us, would be a great consolation to me.

This thread my head hurt. If something happened it happened. If it didn't it didn't. Too much spacey wacey stuff.... I prefer dealing with solid stuff.
Well in the long term you'll be nothing, or atoms. Depends how you view that kind of thing. Think of the human body as a PC. Just one that lasts nearly a century!

I imagine our DNA would be the perfect place to look for something like that.

However, it's absurd to think we're "swallowed into non-existence" just if history doesn't remember you. Your legacy lives on in everything you've ever done and in every way you've ever effected the people or the world around you--which is inevitably an enormous amount. If people don't remember you when you're long gone, then who cares? Get over it. You're a living being and you're changing the universe by participating in existence, and that can never be undone.

Oh i'm not wishing for a claim to fame, not at all, it is the vast universe itself that i want to remember not just me, but all of us, i don't know why, i feel like it would mean something important, like all things, suffering and no hope of an afterlife could be coped with, if i just knew it were not all completely for nothing, and to be imprinted into the timeline of the universe itself would be like a gift from the universe saying, "you see, you aren't worthless to me, i don't let you get swallowed up completely, proof you were there will always be in me".

The universe will end you know?

The story of the universe finally comes to an end. For the first time in its life, the universe will be permanent and unchanging. Entropy finally stops increasing because the cosmos cannot get any more disordered. Nothing happens, and it keeps not happening, forever. It’s what’s known as the heat-death of the universe. An era when the cosmos will remain vast and cold and desolate for the rest of time … the arrow of time has simply ceased to exist. It’s an inescapable fact of the universe written into the fundamental laws of physics, the entire cosmos will die.- Brian Cox

In the vastness of the universe the human species is as irrelivant as a single grain of sand in an infinite beach.

Well, even if there was something like that, the universe will end eventually too. Nothing lasts forever. In the end, what's it all for anyway?

Besides, maybe humanity will go out into the universe and inhabit far more of it than just one little planet. Maybe we'll still be around in some way, shape, or form when the universe itself ends.

Nothing is reality. You all just exist in my imagination and dissappear when I instead think about pies.

Well to be fair, we don't know if our universe is part of many others, they may well be intertwined, different dimensions, more than one big bang perhaps, and then there is the question of infinity, those i suppose are also things that need to be considered, might all be part and parcel of the same reality.

Well, there's that... then there's the "Big Rip" and the "Big Crunch" ideas of the universe's death. THe Big Rip occurs if expansion is too fast, causing atoms, quarks, etc. to literally tear apart. The Big Crunch occurs if the universe is actually closed, and basically the whole thing collapses in on itself.

Fixed.

It makes me think. I had this thought as a kid. If I don't see something and don't hear it, does that make it not real? It's so freakin complex.

Does anyone else find it funny that the some of the names we give to possible end-of-the-universe scenarios sound like names for candy?

sound
¹ ? ?[sound] Show IPA
noun
1.
the sensation produced by stimulation of the organs of hearing by vibrations transmitted through the air or other medium.

So, no.

@ OP - Don't worry, you have a birth certificate and you'll have a death certificate. It'll be proven that you existed, and therefore you have existed.