It really depends on how you define "meaning". Is there meaning to treating a dog with love and respect even though it has no eternal future? How about the kindnesses we do for others - even though they may not notice and they certainly won't recognize us for doing them?
I think we make our own meaning in our every actions - regardless of whether or not those effects last for an eternity... which even with belief in a creator of the universe, there's no reason to believe that physics doesn't rule the universe and that it's not headed for heat death.
One way that I like to think of my permanence in the universe is that there's no reason to believe that every thing we do isn't recorded in time. Sure, our consciousness seems to exist only in the present - but perhaps the existence of our lives isn't totally lost in some form. Perhaps this moment of my typing these thoughts will exist as long as our universe does. Could they be accessed at least in read-only form one day by a future civilization? Maybe.
So that definition of "meaning" would be purely subjective meaning. It's meaning that is self-determined.
In your example, maybe an extra-universal future being might be able to read an echo of our impression on the timeline.
That's dreaming of an idea that might make a hint at a sense of purpose.
But that is what I don't find that fulfilling at all.
What I deeply desire is evidence-based objective meaning, and knowing that you and I and everyone else is truly important and valuable and that the choices we make shape eternal reality.
So that is what I see as the qualititative difference between subjective meaning (meaning purely determined by the subject) and existential meaning (one's existence having an eternal value).
Also, yes the dog would have existential value because it would contribute to the eternal effect. In fact, if there is an Eternal One then love and respect for everything he has designed becomes very important and things made from atoms would carry existential value beyond the physics alone.
As a side note, if there is an Eternal One who cares to be known, then he would have to communicate himself and provide evidence for his existence. (And Yes, I do believe that evidence actually exists and I believe it is very good: it fills my heart with hope and deep meaning as I face the problems of this temporary life.)
Anyway, I appreciate the dialog and I hope it is somehow useful for you.
Thank you for taking the time to think through it with me.
I think we make our own meaning in our every actions - regardless of whether or not those effects last for an eternity... which even with belief in a creator of the universe, there's no reason to believe that physics doesn't rule the universe and that it's not headed for heat death.
One way that I like to think of my permanence in the universe is that there's no reason to believe that every thing we do isn't recorded in time. Sure, our consciousness seems to exist only in the present - but perhaps the existence of our lives isn't totally lost in some form. Perhaps this moment of my typing these thoughts will exist as long as our universe does. Could they be accessed at least in read-only form one day by a future civilization? Maybe.