If you haven't seen the footage of the Bengals' Jerome Simpson making a dramatic both-feet-in-the-air flop backward after what seems like a relatively light shove by the Browns' Scott Fujita, you should. The shove and subsequent flop earned the Browns a 15-yard penalty and sent NFL fans up the wall over Simpson faking it.
Here's the footage:
Watch closely a few times and you'll see the shove happens just after Simpson pulled Fujita out of the pile. Here's just a snip-it of what the Twittersphere is saying:
And although it may seem pretty obvious to some that Simpson may have taken a few acting lessons, one physicist at Southeastern Louisiana University thought he could help confirm or refute such allegations. Rhett Allain reviews the momentum, velocity, and torque that would have been involved in the encounter for Wired.com. Here's what he found:
Clearly Fujita is a Jedi and using the Force to push Simpson.
So, I guess that means Simpson is a faker, or like Allain says, Fujita is a Jedi, which is less likely. Here's how Allain figured it out from a scientific perspective, acknowledging that the data he reviews isn't exact. If Fujita pushed Simpson, conservation of momentum should have occurred. And Allain doesn't believe by his calculations that this happened.
First, Allain points out that it appears Fujita's feet are off the ground during most of the encounter, which shows that horizontal momentum should be conserved, unless of course Simpson is pushing back:
The momentum before and after the “altercation” would be the same if you ignore the players pushing on the ground. For gravity, you can just look at the changes in momentum in the horizontal direction. Gravity doesn’t pull this way, so it wouldn’t have any effect on the horizontal momentum.
This factor comes into play when Allain considers the players' weights and velocity of Simpson moving toward Fujita before getting pushed. When plugged into an equation, these factors reveal that horizontal momentum is not conserved. He says suggests the following options for why this is:
- Fujita was pushing on the ground (giving an external force) during the interaction. This doesn’t seem all too likely since he was not touching the ground the whole time.
- Fujita is a Jedi Knight and using THE FORCE to push Simpson back. The Force (you know, from midi-clorians) could be strong with this one.
- Simpson is a big faker. He pushes off the ground to make it look like Fujita body slammed him.
Allain says that since the change in momentum of Fujita was nearly zero, then the change in momentum of Simpson had to have been caused by the force Fujita exerted against Simpson by pushing against the ground and the ground against him. Allain estimates that Fujita's feet were only on the ground for about 0.3 seconds during the encounter and looking at several factors including Simpson's change in momentum, friction of the ground and cleats estimates that for conservation of momentum to occur Fujita would need to have had an equal but opposite change in momentum. But, he does not.
Allain also looked at torque and angular momentum, saying that if Fujita had pushed Simpson, we would have seen him falling backward a bit after the shove himself. But if you take another look at the video, he seems pretty upright.
For more of in depth technical detail (including equations), check out Allain's piece at Wired.