The original comment, which seems to have been deleted, explained that the plant is also known as a Jade plant. The link talked about why Jade plants might have aerial roots, as they are known. What I took from the article was that the plant is probably either unhappy or has experienced trauma.
In my case, the plant had been unhappy previously because its branches were starting to drop off with increasing frequency. I repotted it, I believe this was a good thing because the branches stopped falling off. However, at the same time, I also turned it around. My guess is that turning the plant around on the windowsill confused it (or gave it trauma).
My analysis of my situation... Some plants are ok to turn around, but I think something like this plant with woody branches like a tree is not able to grow towards the light very quickly. Hence, instead of growing towards the light, it had to make new branches pointing towards the outdoors, and it made some roots on the dark side. It knows where the light is. It knows the light isn't where it was. It knows where it is dark, so it puts roots on the dark side. I imagine in the wild this would be its response if it had fallen over.
The link talked about what to do with the roots. He was saying that you could remove them from the main plant and grow them separately. However, he also said that if the plant is still in the process of making more and more roots, maybe this might be a bad idea, and wait until the roots have calmed down. He also said that cutting off the roots carefully should be ok too.