This is just a series of unconnected thoughts about the mirror universe that I've been pondering lately. They're not really directly connected to Discovery, but I wanted to write them down somewhere!
Why haven't the terrans crossed over to our universe and just conquered everything?
They obviously know about our universe at a high level and are possibly even more technically advanced than us, given all the fancy killing devices they've come up with. (Not to mention that little star they carry around in the imperial flagship!) So you'd think they'd be able to figure out a way to cross over and make a go at taking over the Federation.
Arguments against my fantasy include: 1. since the Federation is cooperative, it probably has a much larger number of ships and personnel to throw at a war; and 2. When the Federation goes to war, it really goes to war, and all this love-everybody talk goes out the window. I could see the show-writers going somewhere interesting with this given how they opened the series with the Klingon mocking of "we come in peace". Season 2: the mirror universe invades ours, and in the course of fighting them, the Federation starts acting even more evil than the Terrans in order to win. (I really hope they don't actually do this, because Season 1 has been dark enough, I would really prefer a slightly lighter-weight next season.)
General implausibility of the mirror universe concept as presented
I feel silly even writing this down, because I usually try not to devote a lot of time and energy to nitpicking the real-physics plausibility of sci-fi shows. But I really liked this observation that I read online a few years ago, by my friend Joe Sondow (who runs a bunch of popular Trek-themed Twitter accounts like RikerGoogling, PicardTips, etc).
His observation is that there's no way a universe with such radically different social dynamics could result in this long sustained history of the same people hooking up and having the same kids over generations to produce genetically identical doppelgangers to people in our universe.
And the more I think about it, it doesn't make much sense for there to be a half-Vulcan Spock on the ISS Enterprise in the original Mirror, Mirror. One would think that Terrans would frown on interspecies relationships, "half-breeds" and non-humans serving on ISS starships!
Speaking of sex…
It occurs to me that the reason they need all the sexiness in the mirror universe is, at the rate people get killed off, you'd need a tremendous birth rate just to keep the population from collapsing!
Okay I'm done.