Paul Gregg from Seattle, a retired engineer who worked for Boeing in research and development, used the skills he acquired with new structural concepts for aerospace to roller coasters. “I saw a couple of people who tried [making backyard roller coasters] online and I thought I could do it a lot better, so things got out of control. I did all the physics and…a whole bunch of engineering stuff. I documented it with PowerPoint charts, so I have about 150 pages of information. I don’t know why. I’m just used to documenting, so whenever I did a test or some analysis or a new design I documented it in that way” said Gregg. Currently, he’s built three: the original coaster, a larger coaster, and a small coaster called the Little Rocket for kids. Click here to view the first image in today’s viral picture gallery. continue reading for the five most popular viral videos today, including one of an infinite chocolate illusion.