Partly because Challenger was the first time something quite like that had happened in the American space program. The Apollo fire was on the ground during a training session, not even an actual launch, and by the time Columbia happened it was just a part of history that a space shuttle had already lown up once.

Then there's also the fact that the shuttles were still relatively new at the time of the Challenger disaster, and kids across the country were watching the launch live, partly due to a teacher being one of the astronauts, so it was kind of a publicity thing.

Columbia was still a tragedy and impacted many people greatly, but it just wasn't quite as unique a situation.

Really doesn't seem that far fetched to me. You've probably never been in NYC. The Jewish population is pretty damn big, and it is one of the places where a hell of a lot of survivors settled, since it's where a lot of them would have entered the US.

The first few are quite slowly paced, but build a whole lot of necessary character and background that leads to very important stuff later on.

I'd definitely reccomend trying again, as a whole it really is one of the best shows in a long while.

You're thinking in terms of traditional computing. What this is referring to is learning neural networks. They operate very differently by design.