Dark Energy

The video explores the concept of dark energy and its role in the expanding universe. It begins with the discovery by Edwin Hubble that the universe is expanding, a finding later expanded upon in 1998 when astronomers observed that this expansion is accelerating. The video discusses the Big Bang theory and gravity's role in the universe's expansion, introducing dark energy as a force that overcomes gravity. It also covers Einstein's cosmological constant, a theoretical force he proposed, and its relevance to dark energy. Various theories about dark energy, including quintessence and virtual particles, are explored.

What role did Einstein's cosmological constant play in the understanding of dark energy?

Discuss the different theories proposed to explain dark energy.