How does general relativity predict an expanding universe?
One of general relativity’s most striking predictions arises if we consider what happens to the universe as a whole. They argued that the universe should start off small and dense, and expand and dilute with time. As a result, galaxies should drift away from each other.
What part of Einstein’s theory can help explain the expansion of the universe?
General relativity lets us calculate and predict exactly how anything with mass will warp spacetime, and how the gravity caused by that warped spacetime will affect not just the matter, but the space, time and light around it.
What do Einstein’s field equations do?
The Einstein Field Equations are ten equations, contained in the tensor equation shown above, which describe gravity as a result of spacetime being curved by mass and energy. , which specifies the spacetime geometry. The inertial trajectories of particles can then be found using the geodesic equation.
What does Einstein’s equation prove?
E = mc2, equation in German-born physicist Albert Einstein’s theory of special relativity that expresses the fact that mass and energy are the same physical entity and can be changed into each other. Furthermore, the energy of a body at rest could be assigned an arbitrary value.
Which scientist predicted that the universe is expanding?
In 1929, Edwin Hubble, an astronomer at Caltech, made a critical discovery that soon led to scientific answers for these questions: he discovered that the universe is expanding.
Did Einstein believe the universe is expanding?
Albert Einstein accepted the modern cosmological view that the universe is expanding long after his contemporaries Until 1931, physicist Albert Einstein believed that the universe was static.. For example, in 1922, Russian physicist Alexander Friedman showed that Einstein’s equations were viable for dynamical worlds.
Did Einstein’s equations predict an expanding universe?
Back when Einstein was formulating General Relativity his equations just could not predict a static universe. I have read that they actually predicted an expanding Universe. Later Friedmann derived an equation from GR that would explain how an Expanding Universe would evolve.
How can we prevent the universe from expanding or contracting?
He multiplied the metric tensor in his equation, g, by the cosmological constant, leading to a term λg, which adjusted his metric tensor acting on space-time. This mathematical trick assured him that his equations would yield a universe that was prevented from expanding or contracting.
What is an Einstein static universe?
In the Einstein static universe, there is a positive cosmological constant on the LHS of the field equation, and a nonzero stress-energy tensor describing ordinary matter and energy on the RHS, and the effects of the two balance in just the right way to make the solution as a whole static.
Was Einstein’s math better than he wanted to believe?
But his math was better than he wanted to believe — his equations told him that the universe could not stay static: It had to either expand or contract. Einstein chose to ignore what his mathematics was telling him.