Another key insight into string theory comes from the holographic principle, which relates a theory in space to a theory defined only on the boundary of that space. The holographic principle isn’t strictly an aspect of string theory (or M-theory), but applies more generally to theories about gravity in any sort of space. Because string theory is such a theory, some physicists believe the holographic principle will lie at the heart of it.
It turns out, as shown by Gerard ’t Hooft in 1993 (and developed with much help from Leonard Susskind), the amount of information a space contains may be related to the area of a region’s boundary, not its volume. (In quantum field theory, everything can be viewed as information.) In short, the holographic principle amounts to the following two postulates:
- A gravitational theory describing a region of space is equivalent to a theory defined only on the surface area that encloses the region.
- The boundary of a region of space contains at most one piece of information per square Planck length.
In other words, the holographic principle says that everything that happens in a space can be explained in terms of information that’s somehow stored on the surface of that space. For example, picture a 3-dimensional space that resides inside the 2-dimensional curled surface of a cylinder, as in this figure. You reside inside this space, but perhaps some sort of shadow or reflection resides on the surface.
Now, here’s a key aspect of this situation that’s missing from our example: A shadow contains only your outline, but in ’t Hooft’s holographic principle, all of the information is retained.
Another example, and one that is perhaps clearer, is to picture yourself inside a large cube. Each wall of the cube is a giant television screen, which contains images of the objects inside the cube. You could use the information contained on the 2-dimensional surface of the space to reconstruct the objects within the space.
Again, though, this example falls short because not all of the information is encoded. If you were to have objects blocking you in all six directions, your image wouldn’t be on any of the screens. But in the holographic principle view of the universe, the information on the surface contains all the information that exists within the space.blogging lessons blogging legally blogging lamp blogging legal issues blogging meaning blogging mama blogging microphone blogging marketing blogging millionaire blogging money blogging meaning in english blogging memes blogging niches blogging niches 2021 blogging networks blogging names blogging niche ideas blogging name generator blogging name ideas blogging niche quiz blogging on instagram blogging on medium blogging on squarespace blogging on shopify blogging or vlogging blogging on facebook blogging on linkedin blogging on wix blogging platforms blogging platforms free blogging platforms examples blogging prompts blogging platforms 2021 blogging passive income blogging pro blogging podcast blogging quotes blogging questions blogging quiz blogging qna blogging que es blogging quora blogging questions for students blogging quotes goodreads blogging rules blogging resume blogging retreat blogging rubric blogging ring light blogging routine blogging revenue blogging recipes blogging sites blogging software blogging sites for free blogging statistics blogging salary blogging synonym blogging services blogging the boys blogging the bracket blogging topics blogging the boys trolling the nation blogging to make money blogging the boys podcast blogging theology youtube blogging under a pen name blogging university blogging using google sites blogging unscramble blogging under pseudonym blogging unscripted blogging udemy blogging uses blogging vs vlogging blogging vs youtube blogging vs vlogging 2021 blogging vs podcasting blogging vs microblogging blogging video camera blogging vs journaling blogging vs instagram blogging websites blogging websites that pay blogging wizard blogging with squarespace blogging website builder blogging websites to make money blogging with google sites blogging without social media bloggingx bloggingx pro bloggingx pro free download xkcd blogging xanga blogging blogging alert xyz explain xkcd blogging blogging your passion blogging youtube blogging your passion podcast blogging youtube channel name blogging your way blogging your way by holly becker blogging your way to the front row blogging your book blogging zones blogging zelda blogging zarada blogging zenith zen cart blogging blogging in zimbabwe blogging in zambia blogging success zone blogging about books blogging about tv shows blogging about food blogging about my life blogging about your personal life blogging about art blogging about pets blogging after retirement bloating after ovulation blogging income after 1 year what after blogging career after blogging retired now what blogs can i retire now blog to blog or not to blog blogging is blogging about blogging blogging as a hobby blogging as a job blogging as a business model blogging as an educational tool blogging as a nurse blogging at medium blogging at work blogging at fl250 blogging at 70 blogging at 40 blogging at 60 blogging at college blogging at the limit before blogging blogging platform before know before blogging tips before blogging considerations before blogging blogging behind the scenes