By Steven Gimbel, Ph.D., Gettysburg College
Erwin Schrödinger’s theory of the superposed state was supposed to present us with a clearer picture of reality, but Albert Einstein believed that the theory was incapable of presenting a picture of reality because it was incomplete. Within the ambit of the theory, it was accurate, but the picture was incomplete.
Einstein contended that every property in the universe had well-defined values at all times. If quantum mechanics failed to provide us these values or failed to uniquely determine these values at all times, it indicated the limitations of the theory and informed us that the theory needed to be augmented. Only then would we get a complete sense of reality.
The First Picture
John von Neumann, a Hungarian-American mathematician and physicist, provided us with the first picture of reality. He claimed that the superposed state was, in fact, real and that objects are spread out without well-defined values until we make an attempt to measure it.
He further claimed that it was the act of measurement that skewed reality. It caused a disturbance that forces the wave function to collapse into a single value. Since the measurement is a physical act, he contended, it changes the system and this causes the results obtained by the application of the Schrödinger equation to change into the random results we see.
The Second Picture
Nobel Prize-winning theoretical physicist and mathematician Eugene Paul Wigner, who was a contemporary and colleague of Neumann, proposed a second picture of reality. His postulation was that the collapse occurs when the system interacts with the human mind. Human consciousness affects the system.
He contended that it’s simply not possible that a physical thing would violate physical law. Hence, the problem didn’t lie with the method or instrument used to observe the system, but with the observer or the scientist. The problem was the conscious seeing of the value.
Learn more about Whether the Conscious Mind is Really in control of Your Body.
It’s worth noting here that a number of scientists found Wigner’s theory of attributing human consciousness with a physical role to be strange.
The Third Picture
American physicist Hugh Everett, the proponent of the many-worlds interpretation (MWI) of quantum physics, provided us with an even stranger image of reality. He posited that the wave function in Schrödinger’s equation never really collapses and that all objects in the superposed state are actually objectively real.
This is a transcript from the video series Redefining Reality: The Intellectual Implications of Modern Science. Watch it now, on Wondrium.
According to Everett, when a system is not observed, it exists simultaneously in every possible state. But when it’s observed, reality splits and new sub-realities or parallel universes are created. And in each of these new sub-realities or parallel universes, one possible state is represented. In other words, every time we observe a system reality is divided into multiple worlds. So, there’s one world where the coin is heads and another where the coin is tails.
Learn more about What Is Reality.
The Copenhagen Dilemma
These three interpretations of reality play a key role when we try to understand the greatest piece of art to be directly influenced by quantum mechanics—Michael Frayn’s stage play, Copenhagen. The play is based on certain events that took place during World War II, and it focuses on the uncertainty that emerged from these events.
It is a well-known fact that German theoretical physicist Werner Heisenberg, who made key contributions in the field of quantum mechanics and was also awarded the Nobel Prize in Physics in 1932, had been recruited by the Nazis to head their nuclear weapons program, which was known as Uranverein.
It is also known for a fact that Heisenberg was stuck. Extensive research had been carried out by various scientists under the Uranverein, between September 1939 and June 1942, but no actual nuclear weapon had been developed. In June 1942, during a meeting with Albert Speer, Germany’s Minister of Armaments, Heisenberg informed him that it would take at least three more years to build a nuclear bomb.
There was a minor (or rather subtle) error in Heisenberg’s work, which prevented him from building a nuclear weapon for the Nazis. Heisenberg had traveled to Denmark during this period to meet his former mentor and colleague Niels Bohr, the Danish physicist and a major contributor in developing a deeper understanding of the atomic structure and quantum theory. After this meeting, Heisenberg and Bohr never spoke again, but we do not know what was said during this meeting.
Over the years, historians have put forward three hypotheses. The first claims that Heisenberg was working with utmost seriousness towards building an atomic weapon for Nazi Germany. When he got stuck, he reached out to Bohr for advice and help. On learning that Heisenberg was working for the Nazis, Bohr refused to help him. This led to a falling out between the two and that’s why they never spoke again.
The second hypothesis claims that Heisenberg, in fact, was conflicted about his involvement with the Nazis. He didn’t want to help them, but neither did he want any harm to come his or his family’s way. This is understandable given the irrationality of the Nazis. Hence, he couldn’t refuse them. This is the reason why he met Bohr, his old mentor, for fatherly advice. They discussed politics and a possible course of action for Heisenberg and physics never came up.
Finally, the third hypothesis claims that Heisenberg had been pretending to work on an atomic bomb all along. He had no intention whatsoever to build such a weapon for the Nazis. In fact, he intended to sabotage the effort. This is where Bohr comes into the picture. The error that would sabotage the effort had to be subtle so it eluded the attention of other scientists in Germany and he needed Bohr’s help for this.
Learn more about Extra Dimensions.
There is no way for us to know which of these three scenarios is true or if there exists a fourth version. If we view this through the lens of quantum mechanics, we can posit that since the system is unobserved, it’s in a superposed state. In Copenhagen, Frayn traces out each of these possibilities in the three acts of the play. Since we didn’t observe it, all three are brought to life. Is there one that really occurred or, as Everett would have it, are there three worlds—in each a different possibility being the real one?
Common Questions About The Nature of Reality
American physicist Hugh Everett had proposed the many-worlds interpretation. It is deterministic in nature. It attempts to explain why the world can appear to be indeterministic to human observers, i.e., scientists.
The wave function, which is also referred to as a state variable, is a key component of any theory. The wave function of the universe is known as the Hartle-Hawking state, named after American physicist James Hartle and English theoretical physicist Stephen Hawking. It’s used to determine the start of the universe. Feynman’s path integral is used to calculate this wave function.
The first attempt at establishing a German nuclear weapons program happened in April 1939, but this effort fizzled out a few months later. In September 1939, Germany made a second attempt at establishing this program, which was known as Uranverein. This second attempt coincided with the start of World War II.
To put it simply, reality represents the state of things in the form they actually exist. It doesn’t take into account how things may appear to exist or as they may be imagined to exist. It includes all that currently exists and all that has existed, irrespective of whether human consciousness can observe or comprehend it or not.