Science
Related: About this forumWhere Do Space and Time Come From? New Theory Offers Answers, If Only Physicists Can Figure It Out
By George Musser
SANTA BARBARAMaybe were just too dumb, Nobel laureate physicist David Gross mused in a lecture at Caltech two weeks ago. When someone of his level wonders whether the unification of physics will always be beyond mortal minds, it gets you worried. Since his lecture, Ive been learning about a theory that seems to confirm Grosss worry. It is so ridiculously hard that it could be the subject of an Onion parody. But at the same time, Ive been watching how physicists are trying to power through their intimidation, because the theory promises a new way of understanding what space and time really are, at a deep level.
The theory was put forward in the late 1980s by Russian physicists Mikhail Vasiliev and the late Efin Fradkin of the Lebedev Institute in Moscow, but is so mathematically complex and conceptually opaque that whenever someone brought it up, most theorists started talking about the weather, soccer, reality TVanything but that theory. It became a subject of polite conversation only in the past couple of years, as math whizzes who take a peculiar pleasure in impossible problems dove in and showed that the theory is not impossible to grasp, merely almost impossible.
Inspired by their bravery, Im going to take a crack at explaining this strange beast, synthesizing lectures Ive attended by Steve Shenker of Stanford University, Andy Strominger of Harvard, and Juan Maldacena of the Institute for Advanced Study, as well as informal chats with Joe Polchinski of the Kavli Institute for Theoretical Physics and Joan Simón of the University of Edinburgh. Im sure theyll set me straight if I get something wrong, and Ill edit this blog post to reflect comments I receive.
Vasiliev theory (for sake of a pithy name, physicists drop Fradkins name) takes to extremes the basic idea of modern physics: that the world around us consists of fieldsthe electrical and magnetic fields and a handful of others that represent the known forces of nature and types of matter. Vasiliev theory posits an infinite number of fields. They come in progressively more complicated varieties described by the quantum-mechanical property of spin.
more
http://blogs.scientificamerican.com/observations/2012/04/12/where-do-space-and-time-come-from-new-theory-offers-answers-if-only-physicists-can-figure-it-out/
Vincardog
(20,234 posts)Odin2005
(53,521 posts)liberal N proud
(60,334 posts)As time passes us by!
rurallib
(62,411 posts)all you have to do is answer 'God" and you pass the course.
Thanks for a mindbender of an article.
veganlush
(2,049 posts)?
Odin2005
(53,521 posts)drokhole
(1,230 posts)(to paraphrase) "My own suspicion is that the universe is not only stranger than we think, but stranger than we can think."
Enrique
(27,461 posts)GeorgeGist
(25,320 posts)after that it gets complicated.
tama
(9,137 posts)with holographic principle or some form of it. Those seem to be the central themes of all promising GUT and TOE candidates these days, and IMO the most advanced and promising of such approaches is Matti Pitkänen's TGD. Spin fields identified with rational numbers sounds to my very limited comprehension like a limited case of Pitkänen's more general idea about rational numbers as common areas between p-adic and real areas, and then some of which I understand even less.
HopeHoops
(47,675 posts)Jim__
(14,075 posts)Or am I completely misunderstanding what it is saying?
The article talks about 2 different holograpic universes and then about our spacetime emerging from the primordial universe as higher spin symmetries broke.
One holographic universe, under an anti-de Sitter geometry (?), has a 3D spacetime reality with a 2 dimensional space and a 1 dimensional time where a 3rd (pseudo)space dimension emerges:
The other holographic universe, under a de Sitter universe, has a real 3D space dimensions lying in an infinite future and a 4th holographic dimension of time:
And then there is the emergence of our spacetime from the primordial universe:
Are these 3 different options? Or, if our universe emerged from a primordial amorphous blob, did it emerge into one of the holograpic universes described above - which one depending on the underlying geometry?
http://en.wikipedia.org/wiki/De_Sitter_universe
The 3D space time is as said, hypothetical, and I assume just for presentation purpose, as also Minkowski space is normally presented as 3D projection of two spacetime cones.
The application of holographic principle to real 4D spacetime needs a spatial boundary where the information theoretical and thermodynamic bekenstein boundary that "holography" seems to refer here, would be observable, and that is impossible with the infinite dimension of time. The hope or promise is that in n-dimensional de Sitter space the holographic principle could be formulated.
The primordial amorphous blob refers to "superposition" of the "supersymmetric" spin scalars that by some spontaneous symmetry break broke down to 4D-space time.
So to my understanding these are not 3 different options, but attempt to unify QM and Relativity at the more general levels of spin scalars and n-dimensional de Sitter spaces.
The question remains, does this model suffer from the same landscaping problem as string/M theories and predict a vast multitude of possible universes, or is it more limiting case of World of Classical Worlds.
Odin2005
(53,521 posts)RagAss
(13,832 posts)Disagree with me and you're a Teabagger !