What Is an Anti Gravity Gun?

Crark: How could we reverse engineer to learn some physics from an existing working piece of technology? And i feel like crark was very specific, like he didn't just want us to talk about hyder reverse engineer technology. He had a very specific example, like it, what if we found three anti gravity guns, and then how would we figure out how those work? We don't even know if it's possible. Maybe dark energy might be repulsive gravity. So i dem stration of repulsive gravity would already revolutionize and re orient all our physics research.