Perpetual Motion Squad
Team name of Leonard, Howard, Rajesh and Leslie as they enter the 29th Annual departmental Physics Bowl. The name was Howard's idea because he thinks the name would hint to the ladies that they "can go all night", a statement which later appears written across their team's T-shirts.
"Perpetual motion" taken literally refers to a movement that does never stop. The idea whether a "perpetual motion machine" can be created or not is one of the field of theoretical physics.
For further information see wikipedia on Perpetual Motion.