Consider that before Tycho Brahe humanity collectively thought the universe was immutable, with planetary bodies forever stuck in the same place like cardboard cutouts in the sky. After Brahe, we agreed that objects in the cosmos were moving. Today, we still argue about how the universe works. Does it expand at a size and rate we barely comprehend? No one truly knows, not even a genius as lauded as Albert Einstein.
Last week researchers uncovered an abandoned model in Einstein's archives that contradicts his position on an expanding universe. It seems that he once struggled internally over the same cosmological questions that he refuted decades later. But he never mentioned it, at least not publicly. While this revelation doesn't significantly alter anything we already know about Big Bang theory, it does bring into question how we know what we know about the universe, the discipline of astronomy and science in general.
If you're looking for an explanation of The Big Bang, my colleague Jonathan Strickland has an excellent piece already available. He makes the point right away that despite its notability, the Big Bang theory is rarely understood. It doesn't describe the origin of the universe; it is simply an attempt to explain how the universe expanded to its present state. Like an episode of "Lost," it also leaves us with more questions than answers. What created the universe? What existed before the universe? Is there anything outside the universe? This is difficult, existential, head-scratching stuff, even for our brightest intellectuals.
Because many predictions about the Big Bang have been proven with observational data, we tend to accept it as fact, even though it's still only a popular theory. The first of these observations was made by Edwin Hubble when he noticed that a star seemed to move faster the further it was from Earth. Fred Hoyle took this a step further with his argument that space could still be expanding, keeping roughly the same density as it did so by generating new matter from elementary particles. While infinite, Hoyle's universe is referred to as "steady state," since its size doesn't change as it expands.
As the story goes, Einstein thought Hubble's theory was flawed. His belief was that the universe was static, rather than steady state. But he couldn't deny that Hubble's findings were supported by his own scientific theories. Now, we've uncovered work of Einstein's that seems to tinker with ideas similar to Hubble's, only 20 years before he disagreed with them.
This paper, called "Zum kosmologischen problem" has been in Einstein's archives all along, assumed to be just the first draft of another paper he authored. Upon further examination however, it appears that Einstein once considered his own theory of an expanding universe, before casting it aside when his math didn't add up.
What's important about this discovery isn't that Einstein experimented with the idea of a steady state universe, but that decades later he found the same concept "abominable" under Hoyle, even when faced with it as a consequence of his own general theory of relativity. How we frame the Big Bang theory often includes this debate with Einstein, which we now find has more than two sides to its story. Like the steady state concept itself, it turns out our understanding of knowledge itself is constantly expanding. What layer will we find peeled back next?
- Castelvecchi, D. "Einstein's lost theory uncovered." Nature. Vol. 506. No. 7489. Pages 418-419. 2014.
- Einstein, Albert. "Zum kosmologischen problem." Albert Einstein Archives. The Hebrew University of Jerusalem, Israel. 1931.
- O'Raifeartaigh, Cormac; McCann, Brendan; Nahm, Werner; Mitton, Simon. "A steady-state model of the universe by Albert Einstein." arXiv:1402.0132 [physics.hist-ph]. Cornell University Library. 2014.
- Strickland, Jonathan. "How the Big Bang theory Works." HowStuffWorks. 6/18/2008. Retreived 2/28/14. http://science.howstuffworks.com/dictionary/astronomy-terms/big-bang-theory.htm