You can change the Past by your Future – A conflict with common sense

To Understand Your Past, Look to Your Future

The mystery of quantum physics has a rich history of proper documentation. The double-slit experiment, showing that light behaves as a wave and with support of photoelectric effect that shows the particle nature of light, concludes that light has dual nature. This reality is strange enough, particularly when it is shown that observing it makes it one or the other. Yes, an observer can create an impact on the phenomenon and all of us experience different realities for apparently same phenomenons.

It gets stranger. According to an experiment proposed by the physicist John Wheeler in 1978 and carried out by researchers in 2007, observing a particle now can change what happened to another one, in the past.

Yes, I wrote, “YOU CAN CHANGE THE PAST.”

According to Young’s double-slit experiment, if you observe which of two slits light passes through, you actually force it to behave like a particle. If you don’t and observe where they land on a screen behind the slits, they appear to behave like a wave.

But if you wait for it to pass through the slit, and then observe which way it came through, you will retroactively force it to have passed through one or the other. In other words, causality is working backward, the present is affecting the past.

Causality refers to the Causal effect means that something has happened, or is happening, based on something that has occurred or is occurring. A simple way to remember the meaning of causal effect is, B happened because of A and the outcome of B is acceptable or unacceptable depending on how much of or how well A performed.

Of course in the lab, the above experiment only creates an effect for negligibly tiny fractions of a second. But Wheeler suggested that light coming from distant stars, that has bent due to gravitational field in between could be observed in the same way. Which could results in observing something right now and changing what happened thousands, or even millions, of years in the past.

Note that, you were wrong about time always. Time is not linear, time is circular. It’s like a loop.

PAST => PRESENT => FUTURE => PAST

And the loop continues.

(The actual flow of time contains several circular dimensions. I mentioned only one for the sake of simplicity. According to Einstein’s theory of General Relativity, there’s no conceptual difference between the past and the future. There’s also no objective reality of time and proof in which time “flows”. In actual practice, all of space and time is just there in some four-dimensional structure. Einstein’s once said, “Time is an illusion.”)

Time loop

The idea, represented in the sci-fi German series DARK. The plot begins in 2019 but spreads to include story-lines in 1986 and 1953 via time travel, as certain characters of the show centric families encounter wormhole in the cave system beneath the local nuclear power plant.

None of these facts are easy to digest, because they’re in direct conflict with your subjective experience of time. But don’t feel guilty. They’re hard enough for physicists to understand and accept, an ongoing tension that puts Quantum Physics in conflict not just with common sense but also with itself.

Richard  Feynman, an American theoretical physicist, known for his work in the path integral formulation of quantum mechanics, was right when he said, “If you think you understand Quantum mechanics then you don’t understand Quantum mechanics.”

“The ‘paradox’ is only a conflict between reality and your feeling of what reality ‘ought to be,” he said.

PS: Don’t stress your mind. Start reading about quantum physics.

Book Recommendation: New Approaches to Quantum Physics by J.R. Croca and R.N Moreira.

I'm a Computer Science graduate from Bahria University, a travel enthusiast and CSS aspirant. I create content and write travelogues for the e-syndicate community. My content area includes International Affairs, Traveling, Technology, Climate Change, Aviation, Space Sciences and Science in general.