His latest interest is nuclear fusion. He can talk for hours about the subject.
The other day, my daughter, son, and I took a little trip to Hobby Lobby to get painting supplies for my daughter (who is also a teenager, and a talented artist). Bubba was on one of his nuclear fusion chat-a-thons. He continued all the way to the check-out line.
When we got there, the cashier started ringing the merchandise, but then stopped. She put everything down and stared at Bubba as he talked about the heat necessary to create a nuclear reaction. He just kept talking. Finally she spoke in her fine southern drawl. "Young man, I have no idea what you're talking about, but it sounds very intellectual. I'm glad there are minds like yours out there to keep society moving on."
Then she turned to me. "Good luck, Mom!"
This is not my son, but he sure sounds like him! You can get a sample of what I listen to every day.
(And if you would like to learn more about nuclear fusion, go here.)