The discussion revolves around the concept of the universe's dimensionality shortly after the Big Bang, specifically whether there was a brief period when the universe could be described as an xy plane with z representing time. Participants explore the implications of this idea and its relation to existing theories, particularly those involving spontaneous dimension reduction.
Participants do not reach a consensus on the validity of the idea that the universe had a brief period of reduced dimensions or its implications. Multiple competing views remain regarding the interpretation of Carlip's work and its relevance to the discussion.
Limitations include the lack of references supporting the initial claim about the dimensionality of the universe and the speculative nature of the connections drawn to Carlip's research. The discussion also reflects uncertainty about the implications of naming conventions in physics.
sloughter said:Shortly after the Big Bang was there an extremely brief period of time when the universe consisted of an xy plane with z as time, the third dimension? In other words did a three dimensional universe predate a four dimensional universe?
I know that Carlip has worked on 2+1-dimensional gravity as a simple model for both classical and quantum gravity, but I can't find any mention that he thinks it has any connection to reality, even at the Planck scale.PAllen said:There is a concept (especially pursued by Professor Steven Carlip) that at very short scales (Planck length), the number of dimensions decreases (spontaneous dimension reduction).
Bill_K said:I know that Carlip has worked on 2+1-dimensional gravity as a simple model for both classical and quantum gravity, but I can't find any mention that he thinks it has any connection to reality, even at the Planck scale.