在1990年代，天文学家利用被称为「标准烛光」的Ia型超新星来测量宇宙的距离与膨胀历史。亚当·里斯及其团队在观测这些遥远的爆炸恒星时，意外发现宇宙的膨胀速度并没有如预期般因引力而减缓，反而在不断加速。这项惊人的发现促使了暗能量概念的提出，并让科学家们获得了诺贝尔物理学奖。

为了解释这项发现与其他宇宙现象，科学家建立了Lambda-CDM标准宇宙模型。该模型指出，宇宙的组成中约有4%是常规物质，26%是暗物质，而高达70%是推动宇宙加速膨胀的暗能量。尽管我们对暗物质和暗能量的本质仍不清楚，但这个模型成功地精确预测了宇宙微波背景辐射等多种观测结果，成为过去二十多年来的核心理论。

然而，随著观测技术的进步，现代宇宙学面临著被称为「哈伯张力」的重大挑战。天文学家利用邻近宇宙的超新星所测量出的当前宇宙膨胀速率（哈伯常数），与透过早期宇宙微波背景辐射和标准模型所预测的数值产生了显著的落差。这种无法忽视的差异暗示了标准模型可能存在缺陷，迫使科学家期待借由新一代太空望远镜的观测数据来解开这个未解之谜。

In the 1990s, astronomers utilized Type Ia supernovae, known as "standard candles," to measure cosmic distances and the universe's expansion history. While observing these distant exploding stars, Adam Riess and his team unexpectedly discovered that the universe's expansion was not slowing down due to gravity as anticipated, but was instead accelerating. This astonishing finding led to the proposal of the dark energy concept and earned the scientists the Nobel Prize in Physics.

To explain this discovery along with other cosmic phenomena, scientists established the Lambda-CDM standard cosmological model. This model posits that the universe is composed of approximately 4% normal matter, 26% dark matter, and a staggering 70% dark energy, which drives the accelerated expansion. Although the true nature of dark matter and dark energy remains unknown, this model has successfully and precisely predicted various observations, such as the cosmic microwave background, serving as the core theoretical framework for over two decades.

However, with advancements in observational techniques, modern cosmology is facing a major challenge known as the "Hubble tension." The present-day universe expansion rate (the Hubble constant) measured by astronomers using supernovae in the nearby universe shows a significant discrepancy with the value predicted using the early cosmic microwave background and the standard model. This unignorable difference suggests potential flaws in the standard model, compelling scientists to look forward to observational data from a new generation of space telescopes to solve this enduring mystery.