Where Knowledge Junkies Get Their Fix
McAfee Secure sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams
Chris Higgins
Carl Sagan Explains the Fourth Dimension
by Chris Higgins - January 26, 2009 - 1:19 PM

We’re all pretty familiar with the first three dimensions — after all, we experience those dimensions daily as we move about our world. But scientists and mathematicians have long gone three dimensions using thought experiments, conceptualizing a fourth dimension — and of course, to many more dimensions beyond. You may have heard of the fourth dimension via Madeleine L’Engle’s A Wrinkle in Time, which mentioned the tesseract, a four-dimensional “hypercube.” In L’Engle’s work, the tesseract had properties that could bend space-time, though a real tesseract would simply be an object in four-dimensional space. Anyway, let’s not get carried away with tesseracts just yet. I stumbled across a wonderful video of Carl Sagan explaining the fourth dimension in a way that anyone can understand. He explains dimensionality as a notion, expanding from a two-dimensional “flatland” to our three-dimensional world, and onward to the fourth dimension. The video is only seven minutes long — have a look:

Neat, huh? See also: Flatland: A Romance of Many Dimensions, a sci-fi story from 1884.

« Previous Post   -   Next Post »
Comments (7)

  1. I remember this from the original broadcast. Not that this brings back a memory, but I have actively remembered this thought experiment for well over two decades now. I don’t know why it stuck in there so well.

    posted by Tim C on 1-26-2009 at 2:13 pm

  2. does anyone else out there remember AK Dewdney’s The Planiverse? it was a follow up to Flatland – a fabulous description of a 2-dimensional world as described by one of it’s inhabitants to humans who “discovered” the world by accident during a computer simulation exercise.

    I thought of it for the 1st time in 25 years yesterday, and here’s Sagan to remind me again!

    posted by Philly on 1-26-2009 at 2:57 pm

  3. @Tim C

    You are not alone. I too saw the original broadcast and never forgot the apple thing. Every time I read or talk about dimensions this apple is right there in my mind’s eye. Go figure.

    posted by That Guy on 1-26-2009 at 6:18 pm

  4. I’m a huge fan of Flatland. It’s really dry at the beginning because the writer takes pains to explain all the details before getting on with the story. But he lock up everything airtight, so there are no “but what abouts”.

    posted by PartiallyDeflected on 1-27-2009 at 12:51 am

  5. I have read Carl Sagan and read about him a lot, but this is the first time I have watched him. Now that I have seen and heard Sagan’s distinctive speaking style, I wonder if Neo’s nemesis (from The Matrix) should have been named Agent Sagan.

    I am pretty sure that Hugo Weaving drew some inspiration from Carl Sagan.

    posted by n2y2 on 1-27-2009 at 3:33 pm

  6. Does anyone else think this guy sounds like Agent Smith?

    posted by andy on 2-11-2009 at 8:09 am

  7. There’s one logical flaw, though. Nothing can exist in flatland, because even a pixel point existing above ground would involve the third dimension immediately. So no square, no triangle, no circle, etc. can exist there. Therefore the lecture has to stop here itself! Sorry Carl.

    Secondly, even if the square were to exist, all he would be able to see would be the pixel points adjacent to his eyes. He would not even be aware of his own shape/boundaries, because he cannot have a ‘bird’s eye view’!

    posted by Hadippa on 9-1-2009 at 3:22 am

Comment

commenting policy