I've liked the series up to this season. I don't really dislike it now but I think that there has been a noticeable drop in quality this season. The series still has its moments but I dunno. It is starting to feel like the writers are running out of ideas and are just coasting.

"Coasting" is exactly the word I was going to use. The show is so successful that it doesn't really have to strain itself anymore, and certainly doesn't feel the need to shake things up. I keep watching it because I have fun with it as comfort food, and I still laugh at some gags, but the show hasn't fired on all cylinders for a while now. It still fun though. I suppose I'm pretentious and depressing often enough they I'm occasionally entitled to a little comfort food .

The show used to be funny because of the situations the characters were in. Now it's just predictable character moments. Penny has to show her rack, Sheldon has to say something cruel, Raj has to say something incredibly gay, Bernadette has to go from sweet to mean.

This episode was okay, but it was a very poor way to introduce Raj's father. Having him show up in the flesh is a strong enough idea to be the "A" story for an episode. Having him at the party was an afterthought. Did he even get up from his chair? Why did he even get divorced int he first place?

I agree with a lot of what you say here. At least up to this season that was how I felt about the series. Predictable but good "comfort food" or "junk food" tv. This season to me has just seemed to be a string of weak to average episodes. I still enjoy it to an extent but I've mostly been watching it out of habit and the fact that there isn't a lot else on that I want to watch.

Why would a clean room have a loading door?

You gotta get that equipment in somehow.

Actually any building like that would have been designed with a loading dock out back long before a clean room was put in. The problem comes from the plastic curtain. It will keep the dust down but it wont seal the floor. A real clean room would have an actual door that seals.

For that matter, wouldn't a clean room require face masks?