Cosmological constant is a physics term generally denoted by the symbol lambda. Lambda is a Greek letter that looks like a triangle missing its base. The cosmological constant was developed by Albert Einstein to be a modification to his original Theory of Relativity. At that time Einstein was trying to posit that the universe is in a static or unchanging state. This would imply that the universe is neither expanding nor contracting.
This cosmological constant was intended to act as an inverse of gravity. In Einstein’s static universe theory the presence of gravity would dictate that the objects of greater mass would attract objects of lesser mass, in short gravity would not allow a static universe to exist. The cosmological constant was designed to counteract the force of gravity in Einstein’s modification.
However, later discoveries have shown that the universe was indeed expanding. This, much to Einstein’s chagrin, caused him to accept that the static universe theory was improbable and the cosmological constant to be moot. Further advances in our understanding of the universe showed that there was perhaps a place for Einstein’s cosmological constant. This is again to account to the role played by gravity in the universe’s expansion. The cosmological constant is now being used to explain the acceleration of the expansion of the universe instead of it slowing down.
Explaining Cosmological Constant