• Question: At one hand we have superstring theory with 12 dimensions and on the other hand holographic principle which says the universe can be seen as a 2 dimensional information structure. What does all these mean?

    Asked by rajathjackson to Chris, Dave, David, Fiona, Jack on 21 Jun 2013.
    • Photo: Chris Mansell

      Chris Mansell answered on 21 Jun 2013:


      Hi rajathjackson,

      It’s hard to say what all this means because it is an area of physics which only the most mathematically talented researchers investigate. It is somewhat removed from my own area of expertise. Furthermore, I get the impression that this is a very active area of research where there are lots of open questions. It is also an area of research where there have been very few experiments, which give theorists lots of licence to be quite speculative.

      Sorry if this hasn’t helped much.

      Chris

    • Photo: David Freeborn

      David Freeborn answered on 21 Jun 2013:


      Hi rajathjackson,

      Superstring Theory and the Holographic Principle are not contradictory, even if it seems that. In fact the two theories are closely related.

      String Theorists think there are maybe 11 dimensions (some say 12 like you say, others 10, but the consensus is settling around 11)- 10 spatial dimensions and 1 time direction. These are dimensions of real space- a real description of the Universe. We don’t see most of these dimensions because they are tiny and curled up on themselves, but they still have a physical effect on the Universe.

      The Holographic Principle is not denying the existence of a space of many dimensions. But it’s saying that mathematically speaking, if we simply consider the information content, all we need for the many dimensions of real space is a two-dimensional surface. It doesn’t deny that many dimensions of space “exist”, but the information content can just be stored in a surface of 2.

      You can think of the Holographic Principle as just a mathematical description of the “real” Universe, or as an alternative way to describe it. Personally, I prefer the holographic principle way of viewing the world though. It’s simpler to get rid of un-needed dimensions, but it does take a while to get your head around everything!

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