科學家稱宇宙形成初期可能是一維空間

Did the early universe have just one spatial dimension? That's the mind-boggling question at the heart of a theory scientists say they are on the brink of solving。

The theory was first proposed by physicist Dejan Stojkovic and colleagues from the University of Buffalo in 2010. They suggested that the early universe - which exploded from a single point and was tiny at first - was one-dimensional (like a straight line) before expanding to include two dimensions (like a plane) and then three, which is the world in which we live today. The theory, if valid, would address important conundrums facing particle physicists。

Now, in a new paper in Physical Review Letters, Stojkovic and colleagues have come up with a test that could prove or disprove the "vanishing dimensions" hypothesis. Because it takes time for light and other waves to travel to Earth, telescopes can, essentially, look back into time as they probe the universe's outer reaches. Gravitational waves can't exist in one or two-dimensional space. So Stojkovic reasons that a planned gravitational observatory (LISA) should not detect any gravitational waves emanating from the early universe。

Stojkovic says the theory of evolving dimensions represents a radical shift from the way we think about how our universe came to be. The theory also suggests that space has fewer dimensions at very high energies of the kind associated with the early, post-big bang universe。

If correct it may help to address the incompatibility between quantum mechanics (used to describe the universe of the very small) and general relativity (good at describing the universe on a large scale。) It could also explain why the expansion of the universe is speeding up with the addition of a fourth dimension。宇宙形成初期是否只有一個空間維度？這已成爲科學家即將攻克的某理論的核心問題。

這個想法最早由布法羅大學的理論物理學家德揚•斯托伊科維奇及其同事在2010年提出。他們認爲，宇宙經由某點爆炸形成，初期微小且是一維(像一條直線)，隨後膨脹成二維(像一個平面)，最後形成我們如今生活的三維空間。這個理論如能被證實，或許就能解決粒子物理學家面臨的重要難題。

在《物理評論快報》的一份新論文中，斯托伊科維奇博士和他的同事們提出一種可證明“消失中的維度”這一假設是否正確的實驗。因爲光和波傳播到地球需要時間，所以，當望遠鏡觀測太空的時候，本質上是在回望過去。在一維或二維空間，引力波無法存在。所以，斯托伊科維奇博士認爲，已計劃完善的引力波觀測站(LISA)無法發現任何早期宇宙的引力波。

斯托伊科維奇博士表示，維度變化的理論將徹底轉變人們對宇宙演變的認識和想法。這個理論指出，大爆炸後的早期宇宙，充滿了高能量，反而有較少的維數。

如果假設正確，便可以解釋量子力學和廣義相對論的不兼容原因。量子力學通常描述宇宙的小規模，而廣義相對論擅長描述宇宙的大規模。該假設同時也指出隨着宇宙的膨脹，將會增加第四個維度。