No, it constant advanced up the belt. It was going faster than the belt. I just clicked on the link and watched it again.<quoted text>
In that particular video with the level, the cart consistently fell back. In the other video with no level, the cart appeared to move forward. Yes, I am familiar with Galilean transforms and I know they are accurate within the appropriate constraints.
Do you believe cell phones can pop popcorn? There is a video that shows it happening.
No, cell phones cannot pop popcorn. I know it is possible to fake things on YouTube. It is not very easy to fool people who understand sailing. NALSA is the same group that certified the Greenbird, the world's fastest sailing vehicle. The regularly race wind driven vehicles. This has been written up on quite a few e-zines. Some of which originally said this was impossible. And quite a few school kids have also done this as a school science fair project.
I can even site an MIT expert in aerodynamics who has said that the problem is trivial.
What more do you need?