I see a lot of alternate history surrounding the Civil War that pretty much just has the Confederate side winning instead of the Union.

Is there anyone who's written up an alternate history of what would have happened to slavery over time in the US if the Civil war had not happened at all?

The premise I'm curious about is basically this: Instead of trying to get the slavery question dealt with harshly and immediately, the US decided to continue doing what the founding fathers decided to do; let it slide for a while longer. In the meantime, technology continues to improve how farming is done, and plantation owners that adopt the new technology improve their production well beyond what slave owners are capable of matching. Slavery becomes less and less profitable. The war becomes one of businesses, as the slavery-run businesses get pushed out by the more profitable machinery based farming practices.

By around 1900-1920, most of the people who were slaves would have been freed simply by their owners going out of business. At that point there would be almost no slavery-based plantations still in operation. Then the US passes a law/amendment to abolish slavery and grant citizenship to everyone. Maybe they even combine it with granting voting rights to EVERYONE (including women), and no one really says nay about it because slavery just isn't worth protecting anymore. By extension, states can't claim that the federal government is usurping states rights, since no one really cares to defend slavery anymore.

I think it's an interesting alternative history, personally. Would it be better to have nearly 300,000 die in war and nearly tear the US in two, or let slavery die out on its own over a few more decades?

In regards to the connection between the ratings of professors and their physical beauty, I wonder if the students were also objectively able to learn more effectively as well. My reasoning is this: we know that certain chemicals in the brain, such as dopamine, activate in response to positive stimulus. We know that when these chemicals activate, our brain is switched to a learning-beneficial setting. So, being taught by a teacher that, by default, gives positive feelings to their students by virtue of their appearance, may increase the students ability to learn. Which, in turn, would earn the teacher higher ratings.

Since this would be completely under the radar for any student that wasn't themselves studying something like neuroscience, I doubt many could tell the difference between "I learned the subject well because the teacher was 80% effective at teaching the subject, " vs. "I learned the subject well because I thought the teacher was attractive while they were 65% effective at teaching the subject." All they would care about would be their feeling of aptitude for the subject during and after the class.

It may be that we can prove objectively that teachers should be let go before they become that ugly old troll we all remember, and hated, from school, and hire the younger, bright-eyed, attractive teachers to replace them. Their relative teaching ability doesn't necessarily come into play at all, since an unattractive teacher shuts off the ability to learn at a brain chemistry level, while an attractive teacher makes even generally uninterested students more capable of learning.