Leonard: Now, out of the way so I can sit in my time machine. Okay, I am setting the dials for March 10th, 1876.
Howard: Good choice, Alexander Graham Bell invents the telephone and calls out for Dr Watson.
Sheldon: Wait a minute. I want to see that too.
Leonard: So when it's your turn, you can.
Sheldon: But if we all go back to the same point in time, Bell's lab is going to get very crowded. He'll know something's up.
Raj: Also, since the time machine doesn't move in space, you'll end up in 1876 Pasadena.
Howard: And even if you can make it to Boston, what are you going to do? Knock on the door and say to Mrs. Bell, "Hey, Mrs. Bell, big fan of your husband, can I come in and watch him invent the telephone?
Raj: Mrs. Bell was deaf. Shes not even going to hear you knock.