Quantum Systems Can Flow Forward and Backward in Time

The more we learn about Time, the more questions we have

Hiya!

So, I know the concept of time is one of those topics that are easy to get turned around in. At a certain point, it becomes too confusing to keep track of. This is partly because, for us, time moves in only one direction—forward. It’s is self-evident based on how we experience our reality.

The topic of time is typically saved for philosophical, scientific, and science-fiction debate, not as a reasonable current-day possibility. Whether it ever will be is still unknown, but this week, I came upon a new discovery published just last month, that says on a quantum scale, time flows both forward and backward.

Quick Review

I know, it boggles my mind too, and it took some time before I understood well enough to tell you about it. Now that I do, it actually seems to fall in line with some of the other discoveries we’ve discussed. Bare with me. Let’s see if I can weave it all together as simply as possible. Then on Monday, we’ll talk about a couple of other really interesting discoveries and theories about time.

The Charm Meson Particle

The quantum realm has pretty much always baffled scientists. I’ve written before that quantum physics are the rebels of the universe. Scientists discovered specific laws over the centuries that nature follows that can not be broken, such as the law of gravity. Well, the teeny-tiny microscopic scale of the quantum realm plays by its own set of rules—like how light particles can also be waves.

Remember when I told you about the charm meson particle in Curious Life? Like other meson particles, the charm meson flips between a particle and an antiparticle. It’s unique because of the speed at which it osculates, and this seemingly insignificant detail may explain why there is more matter than antimatter in the universe.

Well, today’s discovery might be kinda like that, but with time.

Time May Correct Itself

A few months ago, I told you that an undergrad at the University of Queensland mathematically solved a time travel paradox.

Germain Tobar was a fourth-year Bachelor of Advanced Science (Honours) student when he found that mathematically speaking, time may alter and correct itself. According to him, if time travel were possible, and you went back in time to stop the pandemic, you’d fail. Mr. Tobar claims that time would find a way to make the pandemic happen regardless of anything you try. His findings solve one of the biggest paradoxes surrounding time travel, known as the Grandfather Paradox.

I wrote about this and another exciting quantum finding on Medium if you want more details. But for now, let’s piece this all together with the new discovery.

Time Flows Forward and Backward

On Novemeber 26, 2021, Communications Physics published a study by researchers and physicists at the University of Bristol that found quantum mechanics blurs the boundaries between time moving forward and backward.

Okay, remember how I said the charm meson particle can flip between being a particle or an antiparticle, and light can be a particle or a wave? In the quantum world, this process of existing as either state depending on which one is being tested is known as the principle of quantum superposition.

Well, the lead author of the new paper, and a postdoctoral research fellow at the University of Bristol, Dr. Giulia Rubino, wondered if the same concept applies to time. Dr. Rubino and her team investigated a quantum superposition with a state that can flow forward and backward in time.

I’m going to skip over the very long and complicated experiment process to get to their results. But real quick, think of the charm meson particle again. Okay, well, the measurements from the quantum system Dr. Rubino and her team studied showed that time moved forward more often than not. However, in some cases, when entropy changes are minimal, the system could actually continue to flow both forward and backward in time.

Of course, each new discovery only brings more questions. At the same time, every new bit of information is a puzzle piece to some of life’s biggest mysteries. As Dr. Rubio told says,

"Although this idea seems rather nonsensical when applied to our day-to-day experience, at its most fundamental level, the laws of the universe are based on quantum-mechanical principles. This begs the question of why we never encounter these superpositions of time flows in nature,"

In other words, if we know that on a quantum level some systems flow backward in time, why haven’t we experienced it on our level?

Perspective Shift

Okay, now to tie it all together. Maybe, Dr. Rubino’s findings help explain why on a macro level (the larger scale that our bodies exist on), we only experience time moving forward. If quantum systems tend to flow forward in time more often than backward, then perhaps that helps explain why we only experience time as moving forward. Similar to how the slowness of the charm meson’s osculation may help explain why there’s more matter!

Dr. Runio’s ponderings about why we don’t see evidence of time flowing backward in nature make me think of Mr. Tobar’s findings of time correcting itself. I mean, maybe it just happens on a level so small that we’re not influenced by the superposition of time. But is it too crazy to think that perhaps when the quantum system flows backward, it leaves our awareness since it’s traveling in a different direction? Maybe those tiny fluctuations contribute to time’s ability to adjust itself— that is if time exists at all… but we’ll dive down that rabbit hole on Monday.

Photo by Lucian Alexe on Unsplash