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tags: #physics #cosmology #relativity

The Cosmological Constant (represented by the Greek letter Lambda, Λ) was a term Einstein added to his equations of General Relativity. Initially, he introduced it to allow for a static, unchanging universe, as was the prevailing view at the time. The constant acted as a form of anti-gravity to counteract the mutual attraction of matter.

When Edwin Hubble discovered the universe was expanding, Einstein reportedly called the cosmological constant his "biggest blunder."

However, in the late 1990s, observations of distant supernovae revealed that the universe's expansion is not slowing down, but accelerating. To explain this, the cosmological constant was revived. It is now the leading hypothesis to explain dark energy, the mysterious repulsive force that seems to be inherent to the fabric of spacetime itself, driving the accelerated expansion of the cosmos.

What was once a "blunder" is now a crucial component of our standard cosmological model, representing a deep mystery at the frontier of Physics.

Reference

Coursera, "Question Reality: Matter"