Borrowing Adam Smith from Robin Hanson:
Let us suppose that the great empire of China, with all its myriads of inhabitants, was suddenly swallowed up by an earthquake, and let us consider how a man of humanity in Europe, who had no sort of connection with that part of the world, would be affected upon receiving intelligence of this dreadful calamity. He would, I imagine, first of all, express very strongly his sorrow for the misfortune of that unhappy people, he would make many melancholy reflections upon the precariousness of human life, and the vanity of all the labours of man, which could thus be annihilated in a moment. He would too, perhaps, if he was a man of speculation, enter into many reasonings concerning the effects which this disaster might produce upon the commerce of Europe, and the trade and business of the world in general. And when all this fine philosophy was over, when all these humane sentiments had been once fairly expressed, he would pursue his business or his pleasure, take his repose or his diversion, with the same ease and tranquillity, as if no such accident had happened. The most frivolous disaster which could befall himself would occasion a more real disturbance. If he was to lose his little finger to-morrow, he would not sleep to-night; but, provided he never saw them, he will snore with the most profound security over the ruin of a hundred millions of his brethren, and the destruction of that immense multitude seems plainly an object less interesting to him, than this paltry misfortune of his own.
Smith has made a keen observation of human behavior. This observation I think can be extended temporally to our future and past selves and similarly to others. We rarely behave as though our future self has importance for us and connection to our past self is largely a fiction. If that is correct, it follows that extending it to others would be even more limited.
If we are largely geographically and temporally limited:
How big is the bubble we live in normally? (A few days and a few miles?)
Does it vary much by person?
What causes it to expand or contract?
When it does expand or contract, for how long does that last?
How often does it expand or contract?
Are there rules that guide this?
Can the interaction of all these bubbles be modeled and if so, what would that look like?
PS The bubble could be thought of as spacetime coordinates.