I drove to work with two helium balloons in my car, WHAT HAPPENED NEXT BLEW MY MIND!!!
When I accelerated, the ski gear heaped in the cargo hold sloshed to the back. But the balloons sloshed to the front hitting me in the head. When I hit the brakes, the helium balloons went to the back and the ski gear, rolled to the front! WHAT THE HECK IS GOING ON HERE!?!?!?!?
Conclusion: Helium Balloons do not obey the laws of physics.
On second thought, Destin might be on to something with this video from his AWESOME YouTube show Smarter Every Day.
Check out his channel, subscribe and enjoy some science. Smarter Every Day.