Horizon looks at dark energy - the mysterious force that is unexpectedly causing the universe③⑨;s expansion to speed up. The effects of dark energy were discovered in ①⑨⑨⑧ but physicists still don③⑨;t know what it is. Worse, its very existence calls into question 嗄lbert Einstein③⑨;s general theory of relativity - the cornerstone of modern physics. The hunt for the identity of dark en...Horizon looks at dark energy - the mysterious force that is unexpectedly causing the universe③⑨;s expansion to speed up. The effects of dark energy were discovered in ①⑨⑨⑧ but physicists still don③⑨;t know what it is. Worse, its very existence calls into question 嗄lbert Einstein③⑨;s general theory of relativity - the cornerstone of modern physics. The hunt for the identity of dark en...