Jack Skellington begins conducting experiments and attempts to look at one of the mistletoe's berries under a microscope. However, he misuses the microscope.

This clip highlights some of Marie Curie's greatest contributions to science: the theory of radioactivity and the discovery of radium.

Sheldon tells Penny that he is still interested in String Theory because it is elegant. He gives a brief explanation of it and states that scientists have been working on it for decades.

Grover explains and demonstrates the concept of force by pulling a rope. He also illustrates how to influence force by inviting friends to pull the rope with him.

Biff and his friends bully George McFly into doing their homework for them. After the bullies leave the cafe, Goldie encourages George to stand up for himself.