There's a small amount of evidence that the frequency cats purr at could be used to stimulate osteocytes and increase bone density in older women with osteoporosis and maybe even astronauts someday.

You need to introduce then to the scientific method when they're still kittens. Ideally before their eyes are open.

My cat kneeds my abdomen when I am constipated and then like 10 minutes later I am running to the bathroom. Pretty cool.