The Spacetime Lemonade Stand

  • By Anna Rothschild
  • Posted 09.08.11
  • NOVA

Would summer be complete without hot days, lemonade stands, and... cosmology? We asked people near the MIT campus to explain spacetime in exchange for free lemonade. See what they said.

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Running Time: 02:17



Posted: September 8, 2011

Female voice: Explain spacetime and get free lemonade!

Man 1: Okay, so the idea behind spacetime is that space and time can really be interchanged and sort of treated as the same thing.

Man 2: The universe essentially has four humanly observable dimensions…

Woman 1: I know nothing about spacetime. I'm a biologist.

Man 2: Three linear dimensions, and one that's in time.

Woman 2: Normally you think about these things as very different sorts of entities, but spacetime is this wibbly-wobbly sort of stuff that combines properties of both spatial dimensions and time.

Man 3: If you travel fast through space, you get what's called time dilation, so, like, you travel through time slower.

Woman 1: The only thing that I think about when I hear that word is "spacetime continuum."

Man 4: Well, time is the stuff that keeps everything from happening all at once.

Woman 1: Time.

Man 4: And space is the thing that keeps everything from getting in everything else's way.

Woman 1: Space.

Man 4: How's that?

Man 5: Spacetime is kind of a fabric in which everything else exists, so that when you're changing one part of it, it bends to accommodate. I guess that's the best way to describe it.

Woman 3: Space is three dimensions and time is supposed to be the fourth, but you can't travel through it like you can through space, so they say. But I think that's just lack of imagination.

Man 6: We're used to thinking about time and space as being two very different things.

Man 3: Uh.

Woman 2: Um.

Man 2: Uh.

Man 5: Jeez, now I can't do it.

Man 6: You only actually see spacetime-y things if you're traveling very fast or if you're in a very strong gravitational field. So it's totally outside our everyday experience. There's no reason in the world we should be able to understand it.

Man's voice: And one free lemonade…

Man 6: Hot diggity dog, I get lemonade!



Video short produced and edited by
Anna Rothschild
Original Footage
© WGBH Educational Foundation 2011
Valse Brillante by G.H. Green performed by Scott Quade
(Main Image: Spacetime Lemonade Sign)
© WGBH Educational Foundation 2011
Special thanks to Jonathan Ellenberger and everyone who visited the lemonade stand.

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