September 6, 2026
As mentioned Einsteins theory described gravity as mass interacting with spaces, curving it like you might get if you placed a bowling ball on a trampoline. His description however although more accurate than Newton needed some repulsive force to keep matter from congealing together into one massive ball. Einstein added a constant to his equations which he called the cosmological constant. This allowed for time-space to not compress and allowed for the empty spaces between bodies in the universe. Other physicists questioned Einsteins cosmological constant suggesting that in fact the density and radius of the universe changed or varied with time. Einstein rejected this theory and wrote rebuttals of the scientists who suggested it favouring a steady state universe.
In 1927 Belgian physicist Georges Lemaitre offered solutions to Einsteins field equations based on observations of distant galaxies. Lemaitre used Vesto Slipher’s research on the doppler effect and distant galaxies. The data indicated that galaxies that were further away were moving faster than those closer Galaxies. His solution suggested a universe which was expanding in all directions expanding in a spherical shape. This further implied that in the past the universe was also smaller. As mentioned above Einstein was highly critical of this theory.
In 1931 Einstein famously visited Mt Wilson to look through Hubble’s telescope this event is often presented as the definitive moment that changed Einsteins mind. Upon considering Hubble’s data which showed red shift of galaxies was proportional to their distance Einstein was forced to admit that the universe was expanding. He called his insistence on his cosmological constant the greatest blunder of his life. Red shift is caused by the lengthening of light waves into the infrared spectrum caused when an object is moving away from the observer. Thus, more redshift indicates greater speed of movement away.
The implications of this expanding universe were immediately evident to scientists. British Astrophysicist Arthur Eddington said “Philosophically, the notion of a beginning of the present order is repugnant to me.” Einstein himself expressed a similar sentiment regarding Lemaitre’s hypothesis saying his primeval atom hypothesis was inspired by the Chrisitan dogma of creation, and totally unjustified from the physical point of view.” Robert Dicke explained “An infinitely old universe would relieve us of the necessity of understanding the origin of matter at any finite time in the past. A finite universe, by contrast, would force scientists to confront uncomfortable questions about the ultimate beginning of the material universe itself. It also raised the possibility that the universe had begun in something like a creation event produced by a cause that existed independently of matter, space, time and energy.”
~ Kevin Cleary
