Buongiorno,"Giulio Severini" ha scritto:
> E se lo spazio fosse discontinuo, e con esso il tempo?
> Ci si � mai posti questa domanda?
Si'.
> E che risposte si son date?
Ad es. la loop quantum gravity tra l'altro risponde anche a questa
domanda, ecco un link alla rassegna di Carlo Rovelli:
http://relativity.livingreviews.org/Articles/lrr-1998-1/
A seguito una parte dell'abstract:
"The problem of finding the quantum theory of the gravitational field,
and thus understanding what is quantum spacetime, is still open.
One of the most active of the current approaches is loop quantum gravity.
Loop quantum gravity is a mathematically well-defined, non-perturbative
and background independent quantization of general relativity, with its
conventional matter couplings. Research in loop quantum gravity today
forms a vast area, ranging from mathematical foundations to physical
applications. Among the most significant results obtained are:
(i) The computation of the physical spectra of geometrical quantities
such as area and volume, which yields quantitative predictions on
Planck-scale physics.
(ii) A derivation of the Bekenstein-Hawking black hole entropy formula.
(iii) An intriguing physical picture of the microstructure of quantum
physical space, characterized by a polymer-like Planck scale discreteness.
This discreteness emerges naturally from the quantum theory and
provides a mathematically well-defined realization of Wheeler's
intuition of a spacetime ``foam''. ..."
Ciao
--
Giorgio Bibbiani
Received on Thu Aug 19 2004 - 12:56:45 CEST