Comments on: Ask dcr: String Theory http://www.dcrblogs.com/2010/02/11/ask-dcr-string-theory/ Motivating readers to believe, act, and achieve by looking at life with wit, wisdom, and engaging creativity Mon, 21 May 2012 18:07:57 +0000 http://wordpress.org/?v=abc By: Awake In Rochester http://www.dcrblogs.com/2010/02/11/ask-dcr-string-theory/#comment-30298 Awake In Rochester Sun, 14 Feb 2010 19:21:02 +0000 http://www.dcrblogs.com/?p=2787#comment-30298 I'm sorry that they never brought back Captain Kirk from the dead. I think he is stuck in the 11th dimension. I’m sorry that they never brought back Captain Kirk from the dead. I think he is stuck in the 11th dimension.

]]> By: Hollydale Kennel Club http://www.dcrblogs.com/2010/02/11/ask-dcr-string-theory/#comment-30290 Hollydale Kennel Club Fri, 12 Feb 2010 22:34:54 +0000 http://www.dcrblogs.com/?p=2787#comment-30290 Superstring theory sometimes requires a 10 dimensional spacetime, or else bad quantum states called ghosts with unphysical negative probabilities become part of the spectrum ... depending upon the circumstances of course as DCR has pointed out :-) Now, this creates a problem in d=10 string theory: <i>how to get the d=4 world as we know it out of the theory</i> <b>So far there are two main proposals</b> 1. Roll up the extra dimensions into some very tiny but nonetheless interesting space of their own. This is called Kaluza Klein compactification. 2. Make the extra dimensions really big, but constrain all the matter and gravity to propagate in a three dimensional subspace called the three brane. (For an analogy, your computer screen could be said to be a two brane of three dimensional space) These types of theories are called braneworlds. All of this means there is a lot of computations in my own Brain World Superstring theory sometimes requires a 10 dimensional spacetime, or else bad quantum states called ghosts with unphysical negative probabilities become part of the spectrum … depending upon the circumstances of course as DCR has pointed out :-)

Now, this creates a problem in d=10 string theory: how to get the d=4 world as we know it out of the theory

So far there are two main proposals
1. Roll up the extra dimensions into some very tiny but nonetheless interesting space of their own. This is called Kaluza Klein compactification.
2. Make the extra dimensions really big, but constrain all the matter and gravity to propagate in a three dimensional subspace called the three brane. (For an analogy, your computer screen could be said to be a two brane of three dimensional space) These types of theories are called braneworlds.

All of this means there is a lot of computations in my own Brain World

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