Dr. Emmett Brown

— Whoa. This is heavy.
— There's that word again. «Heavy». Why are things so heavy in the future? Is there a problem with the Earth's gravitational pull?

— What about all that talk about screwing up future events? The space-time continuum?
— Well, I figured, what the hell.

Marty, the future isn't written. It can be changed. You know that. Anyone can make their future whatever they want it to be.

The time-traveling is just too dangerous. Better that I devote myself to study the other great mystery of the universe: women!

— You don't just walk into a store and buy plutonium. Did you rip that off?
— Of course. From a group of Libyans. They wanted me to build them a bomb. I took the plutonium and gave them a bomb casing full of pinball machine parts.

— Why, that's me! Look at me! I'm an old man! Thank God, I've still got my hair. What's this thing I'm wearing?
— This is a radiation suit.
— Radiation suit? Of course. 'Cause of all the fallout from the atomic wars.

— Well, thanks. Nice talking to you. Maybe we'll bump into each other sometime again in the future.
— Or in the past.

Roads? Where we're going, we don't need roads.

— Sounds heavy.
— Weight has nothing to do with it.

— Then tell me, future boy, who's President of the United States in 1985?
— Ronald Reagan.
— Ronald Reagan? The actor? Then who's vice president? Jerry Lewis?

This is truly amazing. A portable television studio. No wonder your president has to be an actor. He has to look good on TV.

One shouldn't know about his own destiny. If I know too much I endanger my own existence just as you've endangered yours.

— Oh, this is heavy, Doc. I mean, it's like I was just here yesterday.
— You were here yesterday, Marty.

— Wait a minute. Wait a minute Doc, uh, are you telling me you built a time machine … out of a DeLorean?
— The way I see it, if you’re going to build a time machine into a car, why not do it with some style?

— «Hill Valley weather this Saturday night. Mostly clear, with some scattered clouds».
— Are you sure about this storm?
— Since when can weathermen predict the weather, let alone the future?