Another question

I just finished reading Brian Greene's "The Elegant
Universe". The section in chapter 15 titled "What are
Space and Time, Really, and can we do without them?"
suggests in my mind a tantalizing question:

"Is there an elementary particle (possibly related
to the graviton) which defines three dimensional space?

Any comments on this would be appreciated.

Could you clarify what you mean by "defining three dimensional space"?
I'm not wuite sure I understand what you mean.

Thanks,
N.

Zdenek Jizba wrote:
I just finished reading Brian Greene's "The Elegant
Universe". The section in chapter 15 titled "What are
Space and Time, Really, and can we do without them?"
suggests in my mind a tantalizing question:

"Is there an elementary particle (possibly related
to the graviton) which defines three dimensional space?

Any comments on this would be appreciated.

Nalin Ratnayake wrote:

Could you clarify what you mean by "defining three dimensional space"?
I'm not wuite sure I understand what you mean.


According to Brian Greene (The Elegant Universe) the latest theory
of Everything is called M-theory. It postulates the 10 dimensional
Calabi-Yau space in which the extra dimensions are curled up. Objects
in this space can be one dimensional (strings) two dimensional (membranes)

three dimensional (3-branes) and conceivably with even higher
dimensions. (I am not sure my explanation is correct but it is probably
close.)

A 3-brane would be an object that fills a space of three dimensions. My
suggestion (feel free to call this my fantasy) is that at the beginning
of the "big bang" when the exponential expansion (inflation) got started,
space and the mass of the universe were small. However under the
temperature of 10^28 degrees K, strings as well as other "branes"
including 3-branes started to replicate (think of popcorn) in such a way
that the high temperature was maintained. This process may have
continued indefinitely, except that the 3-branes overtook the mass
particles so that the expansion cooled to the point where only 3-branes
continued to increase leaving the total mass of the universe at its
present state.


Thanks,
N.

Zdenek Jizba wrote:
I just finished reading Brian Greene's "The Elegant
Universe". The section in chapter 15 titled "What are
Space and Time, Really, and can we do without them?"
suggests in my mind a tantalizing question:

"Is there an elementary particle (possibly related
to the graviton) which defines three dimensional space?

Any comments on this would be appreciated.