What is the Holographic Principle and how is it related to string theory?

[Dysprosium]

Can anyone give me a basic definition of what the "Holographic Principle" is, exactly? Or care to discuss the idea at all? Thanks.

 

[Ambitwistor]

There are various technical definitions floating around, but the basic idea is that the information about all the physics going on within a region of space is actually captured by, and may be reconstructed from, the physics going on just at the boundary of that region.

Here is a review:

http://arXiv.org/abs/hep-th/0203101

It's technical, but you can skim over the math.

There is a layman-oriented discussion of the holographic principle in the book, Three Roads to Quantum Gravity by Lee Smolin.

 

[hamlet69]

looking inside out

this is just my idea but , since string theory has up and maybe more diminsions than our three , four if you count time , but if we inside the hollowgram everything would appear really but from the ouside we could see it but not touch it , i oftern think that when we see stars that there are projections from a time past and if we could get they we would find that there are only light and nothing more

 

[marcus]

Originally posted by Ambitwistor
There are various technical definitions floating around, but the basic idea is that the information about all the physics going on within a region of space is actually captured by, and may be reconstructed from, the physics going on just at the boundary of that region.

Here is a review:

http://arXiv.org/abs/hep-th/0203101

It's technical, but you can skim over the math.

There is a layman-oriented discussion of the holographic principle in the book, Three Roads to Quantum Gravity by Lee Smolin.

This by Raphael Bousso is an impressive article, which appeared in American Physical Society's
"Reviews of Modern Physics" vol 74, number 3 pp 825- etc (2002).
this is as authoritative and mainstream as it gets, I suppose.
Well written. Thanx again to AmbiT for a great link.

Also Bousso is at the UC-Santa Barbara ITP (Institute for Theoretical Physics) where so many String celebrities are based. He seems to have an informed, experienced, insiders perspective, see his discussion "String theory and the holographic principle" on page 38.