We as individuals are not going to live forever, at least in our present bodily form, but we might leave a legacy that would potentially last as long as the Earth, and in some ways as long as the Universe. You could be as available at that distant time as you are right now on the internet as an upgraded avatar. It would need some things to happen within the next ten years, but they are technologically doable.
Your dead body if very carefully preserved in the Precambrian bedrock in the Australian west might be findable and identifiable in a billion years, but it would be difficult to put something there that would enable a sentient being such as another human to be interactive with a presently simulated you. You could put some pictures engraved in stone that could survive, or sculptures of you made of stone that all of your current friends would probably recognize. However, that doesn’t seem very appealing and I suspect that even people who live in Australia don’t bother with that kind of permanent burial. A picture of you isn’t much of a legacy except to your children and they will be gone too in a million years.
I met a traveller from an antique land
Who said: Two vast and trunkless legs of stone
Stand in the desert. Near them on the sand,
Half sunk, a shatter’d visage lies, whose frown
And wrinkled lip and sneer of cold command
Tell that its sculptor well those passions read
Which yet survive, stamp’d on these lifeless things,
The hand that mock’d them and the heart that fed.
And on the pedestal these words appear:
“My name is Ozymandias, king of kings:
Look on my works, ye Mighty, and despair!”
Nothing beside remains: round the decay
Of that colossal wreck, boundless and bare,
The lone and level sands stretch far away.
Percy Bysshe Shelley – January 1818.
Some people leave a monetary legacy to their children and some leave money to foundations for some public good. A park bench with your name on it might be appealing and not cost much money. There are a few of those here in Bend, Oregon, with family names that I recognize although I didn’t know the people they memorialize. In a billion years those kinds of physical legacy items will be long gone.
None of those things mentioned will have a billion-year legacy, most won’t even have a hundred-year legacy and you and I will be totally gone! But the collective we, as a technologically advanced society, as a currently living species, can leave a meaningful legacy that can persist for a billion years. It would be a legacy that could be revered by sentient species at that distant time, and it could be designed in such a way that you as an individual could be experienced by those distant beings. Those beings would revere us as gods because we would be the very ones who made their being possible. They would be our children and we would be theirs.
It would even be possible at that distant time to create an identical physical twin of you or me, and to raise us with human experiences like we have had, and thus to be humans so near to you and me that our current friends would easily recognize us and become our personal friends again. It would be like meeting old friends whom we haven’t seen for ten years.
Hi, George. How’s your farm doing this year? Mine has produced far too many squashes; can you use a few?