Why Einstein Could Not Predict the Expanding Universe: A Historical Perspective on Cosmology

The idea of a Big Bang, the origin and expansion of the universe, has its roots in the work of several early 20th century scientists. However, the concept was not fully realized or predicted by Albert Einstein, one of the greatest minds of the 20th century. This article explores why Einstein could not predict the expanding universe and highlights the contributions of Georges Lemaicirc;tre, Vesto Slipher, and Edwin Hubble.

The Early Observations Leading to the Big Bang Theory

The first astronomical observations that pointed to the Big Bang nature of the universe were announced by Vesto Slipher at the 1914 meeting of the American Astronomical Society. Slipher described his discoveries beginning in 1912 that many galaxies were receding away from Earth at high velocities. This was a significant initial indication of the universe's expansion.

The Inferences from General Relativity

In 1916, Einstein published his general relativity theory. If one of his equations of general relativity is subtracted from the other, it implies that the universe must be expanding. In 1922, Alexander Friedmann, a Russian meteorologist, found a simple algebraic error in Einstein's equations, demonstrating that either the expansion of the universe would go on forever or stop and be followed by contraction. This was a crucial step, but it still lacked strong observational evidence.

The Work of Georges Lemaicirc;tre

Georges Lemaicirc;tre, a Belgian Catholic priest and cosmologist, was the first to propose the Big Bang theory. In 1927, two years before Hubble, Lemaicirc;tre published his paper in the Monthly Notices of the Royal Astronomical Society. He published the paper in French in 1927 titled “A Homogeneous Universe of Constant Mass and Increasing Radius Accounting for the Radial Velocity of Extra-Galactic Nebulae.” While Lemaicirc;tre did not prominently highlight the connection with religion, he believed that science and religion could stand independently. His mathematical and physical insights were more focused on contributing to the field of cosmology.

Einstein's Reaction to Lemaicirc;tre's Work

Interestingly, when Lemaicirc;tre sent his preliminary results to Einstein, the latter was appalled. Einstein wrote back, “Vos calculs sont corrects mais votre physique est abominable,” which translates to “Your calculations are correct, but your physics is abominable!” However, this did not deter other scientists from building on Lemaicirc;tre's work.

The Contributions of Howard Robertson, Hubble, and Einstein

Noel "Bob" Robertson, an American mathematician, independently reached similar conclusions in 1928, further solidifying the expanding universe theory. Hubble's observations in the 1920s provided the critical evidence needed to confirm the expanding nature of the universe. The discovery that galaxies were moving away from us supported the idea of an expanding universe.

Although Einstein initially rejected Lemaicirc;tre's theories, he later conceded, acknowledging the importance of the expanding universe theory. This shift in Einstein's stance was a significant moment in the scientific community.

Key Discoveries and Confirmations

The confirmation of the Big Bang theory came with the discovery of cosmic microwave background radiation in the 1960s, led by Arno Penzias and Robert Wilson. This discovery was a major milestone, providing direct observational evidence for the Big Bang model. The Cosmic Background Explorer (COBE) satellite, launched in 1990, further supported the Big Bang theory by evidence indicating there was only one Big Bang.

The Term "Big Bang" and Its Implications

The term "Big Bang" was coined by the English astrophysicist Fred Hoyle in the 1940s, purportedly as a pejorative term to criticize the theory. Despite its catchy name, the term is now widely used in the scientific community. It refers to the hypothetical state of the universe from which all matter and energy in the universe were supposedly created, and it describes the universe as expanding over time.

Conclusion

The expanding universe theory, known today as the Big Bang theory, was a radical departure from scientific orthodoxy in the 1930s. Einstein, while initially resistant, eventually embraced this theory. The contributions of Lemaicirc;tre, Slipher, Robertson, Hubble, and others played a crucial role in establishing the Big Bang theory. The accumulation of evidence over the decades has confirmed this theory as a fundamental pillar of modern cosmology, and it stands as a testament to the power of scientific collaboration and the pursuit of truth.