Therefore, you can (theoretically) go back to the year 2022 – this physicist is researching time travel

When physicists talk about time travel, they always start at the party hosted by world-renowned physicist Stephen Hawking on June 28, 2009 – but no one else showed up. The story is now also told by Vilasini Venkatesh, and it goes like this:

To experimentally test the idea of ​​time travel, Hawking threw a party, provided ice-cold champagne, and a lavish buffet. However, he did not send the invitations until after the ceremony to ensure that only those who could travel back in time would show up. However, since no one showed up, the exceptional physicist concluded that the failed batch is proof that time travel to the past is impossible.

However, physicist Vilasini isn’t convinced that time travel is off the table: “Perhaps no time traveler liked ice-cold champagne,” she says, who researches time travel at ETH Zurich, and laughs.

Dealing with time travel sounds like a hobby for science fiction fans. In fact, well-known scientists have also been interested in the subject for some time. More precisely, since the logician Kurt Gödel had found an amazing solution to the equations of Albert Einstein’s theory of relativity: according to this, time travel to the past is at least theoretically possible.

Time travel may sound like abstract mind games at first, as Vilasini admits. But:

The 28-year-old Vilasini Venkatesh, who grew up in New Delhi, dabbles in things that sound cryptic to us: “Relativistic quantum cryptography,” for example, which she works on in the group of ETH quantum information scientist Renato Renner. As a 12-year-old girl, her aunt, a math professor, taught her abstract math concepts like infinite series or vector spaces “in an interesting and understandable way” at the kitchen table, Vilasini says.

She also discovered the biography and notes of Richard Feynman, winner of the Nobel Prize in physics. “In his books has me especially the madness and at the same time the beauty of quantum physics attracted – a fascination that still drives me in my research.”

However, the researcher does not stop at physical and mathematical equations. In art she brings her insights to life. Her passions also include music, poetry and drawing. Her self-composed songs and poems are inspired by concepts from quantum physics. Each chapter of her dissertation contains a poem that lyrically summarizes the research results.

The instrumental pieces on their first short album « Reflections », released two years ago, are inspired by the physics of water and light. “Music and mathematics are closely linked,” says Vilasini, a connection that has been explored by Indian musicians and mathematicians since ancient times.

“Vilasini clearly has many talents,” says Roger Colbeck, her doctoral student, who studies at the British University of York. What sets her apart is her strong passion for research, her creativity and her optimism. The latter enables her “to persevere with difficult problems where others would give up”.

In her dissertation, Vilasini sat down at the table Cause and effect phenomena and logical paradoxes apart – the two bottlenecks for time travel. Because the paradoxical scenarios that inevitably unfold are often put forward as a compelling argument against time travel. Vilasini illustrates this with the famous grandfather paradox:

But such contradictions, says Vilasini, are by no means a reason to rule out time travel:

The physicist beams and talks himself into action.

Correspondingly, there is the many worlds theory, the fierce representative of which is the quantum information theorist David Deutsch. “Let’s go back to the grandfather paradox,” says Vilasini, always careful to convey the very complex matter in an understandable way.

The great thinker David Deutsch is convinced of this theory. In an interview with “Spiegel”, when asked if he really believed in this crazy idea, he once replied: “Absolutely. Physics tells us.”

Vilasini explains that the many worlds theory is not the only possibility for consistent time travel. There is another theory she prefers. It was developed by American physicist Seth Lloyd and is similar to the time travel model in “Harry Potter and the Prisoner of Azkaban”. The idea behind it is that while you can travel back in time, the universe limits what you can do. “In the case of the grandfather paradox, for example, you might imagine that every time you pull the trigger, the bullet is missing from the gun, and therefore the murder can never happen.” The story is, as it were, already written in the stars. And then, according to Vilasini, philosophical questions arise, namely whether this theory endangers free will.

But recently she and Roger Colbeck have mathematically shown that there are apparent universes in which no paradoxes need arise, even if free will is guaranteed. Accordingly, the future can influence the past, so that contradictions do not arise under certain circumstances. Such so-called causal loops are even possible in universes similar to ours, as Vilasini and Colbeck discovered. However, so far they have only been able to prove this for one-dimensional models. Vilasini is currently investigating with a master’s student whether causal loops and thus time travel are also possible in three spatial dimensions, as they occur in our universe.

And where would the physicist travel if she ever could? Probably not at Stephen Hawking’s party, she notes with a wink. She would rather meet her grandfather. “And instead of threatening him with a gun, I talked to him over a cup of coffee about life in his time.”