從黑洞力學四定律與熱力學四大定律的相似性出發，物理學家發現黑洞是一個熱力學系統。除此之外，黑洞的熵值正比於其表面積而非體積，此一事實導致了重力的全像原理(猜想)。Ted Jacobson的研究工作強烈暗示：不只是黑洞，時空本身可能便是一個熱力學系統。Erik P. Verlinde以全像原理及某些時空的熱力學特性為假設，在去年提出了一個革命性但備受爭議的想法：我們所認知的(3+1)維時空是由一個(2+1)維的時空突現(emergent)而來，除此之外，重力是一種熵力。在本論文中，我們將對把時空視為一個熱力學系統的概念作回顧(第一、二章)、試著把Verlinde的想法敘述清楚(第三章)、並討論某些可能實現他的突現性時空圖像的線索(第三至五章)。 Starting from the resemblance between the four laws of black hole mechanics and those of thermodynamics, physicists find that the black hole is a thermal system. In addition, the entropy of a black hole is proportional to its surface area instead of its volume. This fact leads to the holographic principle (conjecture) of gravity. Ted Jacobson's work strongly suggests that not just black holes, but the spacetime itself may be a thermal system. Taking the holographic principle and some thermodynamic properties of spacetime as assumptions, Erik P. Verlinde proposed a revolutionary but highly controversial idea last year: our (3+1)-dimensional spacetime is emergent from a (2+1)-dimensional spacetime, in addition, gravity is an entropic force. In this thesis, we would make a review on the ideas of treating spacetime as a thermal system (Chapter 1 and Chapter 2), try to clarify Verlinde's ideas (Chapter 3) and discuss about some possible hints for the realization of his emergent picture of spacetime (Chapter 3 to Chapter 5).
