Thanks for your time and attention.
We have never observed anything in the universe just popping into existence from nothing (...)
if we did, that would be a major shift in physics. in this regards I heard of (or read of) two candidates :
.1 if universe's expansion continues to accelerate, (it would mean) dark energy is increassing.
.2 an excess of hydrogen (clouds) outside of galaxies was observed that is difficult to explain with current cosmology.
I know these are not direct observation of something popping up, ...but still.