Zakaj ima prostor tri razsežnosti?

    Trije fiziki so pravkar objavili članek, v katerem pojasnjujejo, zakaj ima naše vesolje prav tri prostorske razsežnosti. Razvili so teorijo, po kateri je bila izbira treh prostorskih dimenzij in ene časovne v prvih trenutkih po velikem poku posledica selekcije na osnovi drugega zakona termodinamike.

    “A number of researchers in the fields of science and philosophy have addressed the problem of the (3+1)-dimensional nature of space-time by justifying the suitable choice of its dimensionality in order to maintain life, stability and complexity,” coauthor Julian Gonzalez-Ayala, at the National Polytechnic Institute in Mexico and the University of Salamanca in Spain, told
    “The greatest significance of our work is that we present a deduction based on a physical model of the universe dimensionality with a suitable and reasonable scenario of space-time. This is the first time that the number ‘three’ of the space dimensions arises as the optimization of a physical quantity.”
    The scientists propose that space is 3D because of a thermodynamic quantity called the Helmholtz free energy density. In a universe filled with radiation, this density can be thought of as a kind of pressure on all of space, which depends on the universe’s temperature and its number of spatial dimensions.
    Here the researchers showed that, as the universe began cooling from the moment after the big bang, the Helmholtz density reached its first maximum value at a very high temperature corresponding to when the universe was just a fraction of a second old, and when the number of spatial dimensions was approximately three.
    The key idea is that 3D space was “frozen in” at this point when the Helmholtz density reached its first maximum value, prohibiting 3D space from transitioning to other dimensions.
    (Vir:Why is space three-dimensional? –

    Izvorni članek: Julian Gonzalez-Ayala, Rubén Cordero and F. Angulo-Brown. “Is the (3 + 1)-d nature of the universe a thermodynamic necessity?” EPL. DOI: 10.1209/0295-5075/113/40006 (v prostem dostopu: arXiv:1502.01843 [gr-qc])