[antognini]

(Chiming in as someone else with a PhD in astronomy.)

Eh... It's true that strictly following the rules of logic you can't disprove these ideas with an ad hominem. But as a researcher you only have so much time, and oftentimes the errors can be subtle. If a researcher has gotten a reputation for publishing a string of outlandish papers that fall apart under scrutiny, it's just not worth the time to go into them and figure out why exactly they're wrong.

One of the reasons this guy has gotten a reputation for himself is because he keeps publishing sensational results, uses his credentials to gin up media interest, the press picks it up, and then the rest of the community is forced to engage with the ideas to the outside world. The way it would ordinarily work is that he would submit his ideas to a journal, a few reviewers would spend the time finding all the holes in the ideas and either the paper would be published with the sensational claims toned down, or it would be rejected. In my view, the main point of peer review is to make sure that all the obvious problems in a paper have been fixed before it gets published so that most researchers don't waste their time trying to understand garbage. But he engages in a sort of end-run around the peer review process.