Toggle light / dark theme

Australian physicists resolve time travel paradox, showing it could be possible according to einstein’s theory.

Australian physicists have demonstrated that time travel could be theoretically possible by resolving the classic grandfather paradox. By aligning Einstein’s theory of general relativity with classical dynamics, researchers at the University of Queensland showed that time travel scenarios, such as altering past events, can coexist without resulting in logical inconsistencies. They used a model involving the coronavirus pandemic to illustrate how events would adjust themselves to avoid paradoxes. This research suggests that time travel, while complex, does not inherently create contradictions and could be feasible according to current mathematical models.

After reading the article, a Reddit user named Harry gained more than 524 upvotes with this comment: Isn’t the problem with time travel that it is also space travel? The earth isn’t in the same spot now as it was when you first started reading my comment, the earth travels very fast in space so wouldn’t you also have to find out where in space the earth was in 1950 (chose random date) in order to physically travel there? And how could we know where in physical space the earth was in 1950?

What if everything we know about time is merely an illusion? Could find a way out of it, by breaking the construct of how the universe progresses? And so, would it be possible to break the natural flow of time?

If you’d like to see more of this kind of video, consider supporting our work by becoming a member today!

Follow us on Instagram: / beeyond.ideas.

Visualization of the Gödel universe.

Isaac arthur rokos basilisk.


The dangers of artificial intelligence have long loomed in our future, and seem ever closer. But it may be that the dangers of the future can reach back into the past itself, and even without a time machine.

Go to https://brilliant.org/IsaacArthur/ to get a 30-day free trial and 20% off their annual subscription.

A new theory suggests time travel might be possible without creating paradoxes.

TL;DR:

A physics student from the University of Queensland, Germain Tobar, has developed a groundbreaking theory that could make time travel possible without creating paradoxes. Tobar’s calculations suggest that space-time can adjust itself to avoid inconsistencies, meaning that even if a time traveler were to change the past, the universe would correct itself to prevent any disruptions to the timeline. This theory offers a new perspective on time loops and free will, aligning with Einstein’s predictions. While the math is sound, actual time travel remains a distant possibility.

Have you ever wondered what the universe looked like after the Big Bang when it was still in its infancy, a mere billion years old? With NASA’s new Nancy Grace Roman Space Telescope, we’re about to get a glimpse of the cosmic dawn.

This cosmic time machine is set to explore an era known as the cosmic dawn, a significant transition when the universe went from a foggy opacity to the stunning, star-filled expanse we observe today.

Behind this ambitious project is the esteemed astrophysicist Michelle Thaller from NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The idea of time travel has dazzled sci-fi enthusiasts for years. Science tells us that traveling to the future is technically feasible, at least if you’re willing to go near the speed of light, but going back in time is a no-go. But what if scientists could leverage the advantages of quantum physics to uncover data about complex systems that happened in the past?

New research indicates that this premise may not be that far-fetched. In a paper published June 27, 2024, in Physical Review Letters, Kater Murch, the Charles M. Hohenberg Professor of Physics and Director of the Center for Quantum Leaps at Washington University in St. Louis, and colleagues Nicole Yunger Halpern at NIST and David Arvidsson-Shukur at the University of Cambridge demonstrate a new type of quantum sensor that leverages quantum entanglement to make -traveling detectors.

Murch describes this concept as analogous to being able to send a telescope back in time to capture a shooting star that you saw out of the corner of your eye. In the everyday world, this idea is a non-starter. But in the mysterious and enigmatic land of quantum physics, there may be a way to circumvent the rules. This is thanks to a property of entangled quantum sensors that Murch refers to as “hindsight.”

Quantum sensing can outperform classical sensing by placing the sensor in an initial state that optimally measures the target. However, choosing this optimal state requires having some preknowledge, such as knowing the orientation of a magnetic field in order to measure its strength. A new experiment overcomes this limitation using two entangled quantum bits (qubits), which are manipulated in a way that is equivalent to a qubit traveling back in time [1]. Through this “time travel,” the qubits can be placed in an optimal state without any preknowledge.

“Our work addresses a specific kind of problem that plagues many sensing setups: you have to know which direction to point the sensor,” explains Kater Murch from Washington University in St. Louis. When measuring a magnetic field with a spin qubit, for example, the spin’s rotation will return information about the field strength only if you point it in the optimal direction. Point it in a nonoptimal direction and you’ll get zero information about the field, wasting the measurement.

Murch and his colleagues have devised a protocol in which the probe qubit is entangled with a second qubit, called the ancilla. Following previous work, they show that the entanglement is mathematically equivalent to the ancilla traveling back in time to place the probe in an optimal state [2]. They further show that measuring the ancilla and the probe in a particular sequence can recover information about the field strength in all cases—so no measurement data are wasted as they can be in other protocols. The researchers foresee using this entanglement scheme in situations where a field—or another observable—is changing over time.