That's my exact same thoughts - that the universe is "pulsating"
Starting (or always happening
) with big bang/s .... then gravity eventually pulling it all back together again, to a singularity.. ..starting the process all over again...
I know the universe is expanding (and at an increasing pace). This
may eventually slow down if gravity gets stronger as all the super black holes swallow their galaxies up.. who knows... I'm not that clued into cosmology to be honest, though black holes and photons have always intrigued me more than anything about the cosmos.
No doubt we will understand this better when we unlock the mysteries of dark matter, dark energy, black holes, and all the crazy stuff that happens in the quantum domain. It's fascinating all the progress that are scientific experts are making in each relevant field, thats telling us the true nature of the universe.
Throughout recorded time and long before, trees have stood as sentinels, wise yet silent, patiently accumulating their rings while the storms of history have raged around them --The living wisdom of trees, Fred Hageneder