'Gravity Illusion' Changes San Francisco Hills, Creates Wild Video

This is a trick of the brain.

When dance meets illusion, beauty and fun is certain to come.

Karen X. Cheng and Ross Ching did just that in their most recent video, where using a simple camera trick they created a "gravity illusion" in the midst of an awesome dance routine through the San Francisco hills.

"By tilting my camera on the hilly streets of San Francisco, I made some cool gravity illusions like this one (no special effects or green screens)," Cheng told A Plus in an email. 

As they dance around to the song "I Don't Feel Like Dancin'" by Scissor Sisters, the group is followed on their ascent and descent of massive hills in San Francisco. Finding the right illusions and stuff to use for them wasn't easy, either. According to the YouTube description they had plenty of failures.

Check out the video here: