丁香园AV

Synopsis

The age long quest of humans to understand the workings of the universe has not been short on surprises. Over the past 100 years, our picture of the universe has evolved from assuming it to be static, to accepting that it is expanding and, more recently, finding that the expansion is accelerating. While the fact of cosmic acceleration is well-established, the nature of the so-called Dark Energy causing it remains unknown. Einstein鈥檚 cosmological constant (Lambda), manifested as a constant positive vacuum energy, has been the explanation of choice for the past two decades. However, there are hints in the latest data suggesting that dark energy may be changing with time, challenging the established paradigm. Are we on the verge of another surprise? In this talk, I will review the history leading to the discovery of cosmic acceleration, the latest evidence, and the implications that measuring a changing Dark Energy would have for fundamental physics-archive.