The unified field theory is a term that was initially coined by Albert Einstein. The purpose of the theory is to provide an explanation that ties all phenomena within the universe to matter and energy. Some might call this the Theory of Everything.
Einstein spent the last 30 years of his life attempting to formulate a plausible unified field theory. His goal was to combine electromagnetism and gravity into one single, specific theory. He pursued this effort because he felt like nature could be described by a single theory.
As Einstein stated in 1923:
“The intellect seeking after an integrated theory cannot rest content with the assumption that there exist two distinct fields totally independent of each other by their nature.”
It wasn’t just electromagnetism and gravity that Einstein believed could be combined into one theory of everything. He believed that quantum mechanics could be pared down into one simplistic theory if its paradoxes could be eliminated. By exploring the world of quantum mechanics, he believed that what appeared to be completely random elements of nature could be acceptably explained.
It would be those problems with quantum mechanics that would eventually hold Einstein back from achieving his goal.
Einstein Rejected the Idea of Quantum Mechanics
As the 1950s brought developments into the world of physics, Einstein found himself on the outside looking in. He distanced himself from the rest of the community because he didn’t feel like quantum mechanics could provide the answers he needed. As he continued his pursuit of a unified field theory, he found himself moving further and further away from the rest of the scientific community.
Just a year before his death, Einstein would offer what would become one of his most famous quotes.
“I must seem like an ostrich who forever buries its head in the relativistic sand in order not to face the evil quanta.”
Einstein wrote that in correspondence with Louis de Broglie. It was because he could recognize the fact that general relativity had come from trust that developed with its underlying principles. Einstein felt that the unified field theory would develop from those same principles, so he trusted in them.
That trust would turn from a reliance on fact to a reliance in faith during the later years in his life.
Why Is It So Difficult to Develop a Unified Field Theory?
During Einstein’s research, the discovery of strong and weak nuclear forces interrupted the search for a unified field theory. Einstein hoped that a deterministic unified theory could emerge, but the rest of the scientific community believed that quantum mechanics must be included from the very beginning of the search process.
Three fundamental forces must be incorporated into the theory for it to be unified. These quantum forces are electromagnetism and the strong and weak nuclear forces. Electromagnetism and the weak nuclear force were combined by 1968 into the electroweak theory, thanks to W and Z bosons which have non-zero masses.
In the Standard Model, we know that strong forces co-exist peacefully with electroweak forces, but they continue to remain distinct. The strong and the weak forces have failed to be unified, as have the strong forces unifying with the combined electroweak theory.
Because of these difficulties, different approaches have been taken, based off of Einstein’s work, to come up with theories that include quantum mechanics, which can then be incorporated into the Standard Model. One of the most hopeful attempts is called Causal Sets.
Causal Sets focus on quantum gravity. It states that a bijective map between past and future distinguishing space times that preserve a causal structure will create a conformal isomorphism. The volume of a space-time region could then be found by counting the number of points that are created by volume factors that are generated.
There are, however, no candidate theories for the unified field theory at this time that include the Standard Model of particle physics and Einstein’s general relativity.
Why Are We Pursuing a Unified Field Theory?
For much of humanity’s existence, the idea has been that our planet, our people, and our universe was created by a supernatural being. Although there was the occasional researcher, scientist, or theologian who suggested otherwise, it wouldn’t be until Darwin when the idea of evolution, not outright creationism, was somewhat accepted in human society.
We have always pursued a creator. In doing so, we have pursued a creation that seems to come from one generic principle. Much like many of the religious books describe, “God spoke and then it was.”
Yet the purpose of pursuing a theory of everything goes beyond the need to justify the existence of a divine being. By understanding the core concepts of our universe, we can begin to use our own creativity to take advantage of the underlying rules that are in place. An understanding of science allows human civilizations to progress forward, allowing each generation to benefit from the previous generation’s work.
The universe is so complex and vast, however, that a theory of everything may not even be possible. Several scholars have come to doubt the possibility that it may exist. That includes Stephen Hawking, who wrote the following in 2002.
“Some people will be very disappointed if there is not an ultimate theory that can be formulated as a finite number of principles. I used to belong to that camp, but I have changed my mind.”
Scholars such as Stanley Jaki, Freeman Dyson, Solomon Feferman, and Jurgen Schmidhuber contend that an attempt to create a unified field theory is a practice that is always going to fail. They note that any formal theory that can be expressive enough for a mathematical facts to be expressed has turned out to be incomplete or inconsistent.
Getting One Step Closer to the Unified Field Theory
In 1955, Einstein’s battle with an abdominal aneurism finally began to wane. While working on his theory, he felt a sharp pain in his stomach. The aorta that was affected by the aneurysm had finally begun to rupture. Einstein refused treatment for the condition.
He was taken to the hospital so his condition could be monitored. While there, he continued to work on the unified field theory until he could work no more. Before he finally fell asleep, a final row of numbers and symbols was offered to the world in the hopes that maybe one day, a unified theory could be discovered.
The theory of everything continues to be an elusive prize. Maybe there is one simplistic equation that can explain everything. Maybe the reason why it has not yet been discovered is that it simply does not exist. What we do know is that Einstein put his best effort forward to discover this theory. Even though his efforts may have ended in failure, his perspectives have helped us understand much more about the universe than in generations before.