I had an experience today which forces me to add to this post.

We had to have some heavy equipment lifted onto the roof of the plant and called in a helicopter to get it up there. A good friend of mine stood outside with me and taped the whole episode with his cell phone. With the naked eye it looked like a regular helicopter in action but when we watched the video on his cell phone the rotors weren't turning on the helicopter. It lifted right up off the ground and the rotors weren't spinning at all.

As far as I'm concerned this thread is debunked.

Today I saw a helicopter working perfectly and when I watched the video from my friends cell phone the rotors weren't turning.

It's the camera, not the helicopter.

The two rotors on a helicopter are link by the transmission.

If both rotors were not turning i might believe antigravity helicopters.

But since the tail rotor is turning that means the main rotor is also turning.

That means strobe effect is what you are seeing.

NICE TRY.

you can also tell by the way the blades are bent in a upward directions because of the speed they are rotating if they were not rotating they would be curved down.

If it was an anti gravity helicopter, what is the need for the blades?
to confuse the enemy? haha