I was ignoring him, but now he's saying things like, "our galaxy alone is at least 250 000 000 000 000 earth years old", that gigayears is not enough time for it to evolve, "that there are fully formed galaxies visible from earth that are well over 10 000 000 000 lightyears distant", etc.

My response is, why are all the quasars, which exist in young galaxies, only found far away? That the most distant galaxies are less evolved. That the oldest stars dated in our own galaxy are about the same age as the oldest, most distant galaxies and just under the date determined for the BB.

Also, he claims that "as photons propagate through the vast distances of space
they encounter vast amounts of matter along the way - matter which absorbs photons and creates gravity induced drag on photons which are not absorbed" and "to clarify.. visible light is only capable of travelling a finite distance approximately 1.3 x 10¹⁰ lightyears on average before all source photons are lost". If this were true, then there would a very gradual dimming with distance, not a sharp cut-off near the limit predicted by BBT, and some photons would actually travel much further, especially those coming from quasars, which emit massive numbers of photons. Also, we would be able to measure such a decrease in photons over distance, which I'm sure we don't. Furthermore, all these observations are converging on the same pattern, which was predicted by BBT.

This notion that redshift is caused by gravitational drag from matter, rather than cosmological expansion, I don't quite understand. Wouldn't photons passing close to matter first experience a blueshift, then a redshift that would cancel it out, resulting in no net shift? And any photons actually hitting a particle of matter would be reflected or absorbed, which would cause dimming, as he said, but not redshift.