Everyone is, in a way, a time traveller. Whether we like it or not, we are constantly moving through time — one second per second. From one birthday to the next, we travel through time at a steady pace, just like walking one foot per footstep. However, when we talk about “time travel,” we often imagine something much more dramatic — traveling faster (or even backward) through time, as seen in science fiction movies and novels. But is such a thing truly possible?

From Fiction to Science

The concept of time travel first gained widespread attention through literature, particularly with H.G. Wells’ 1895 novel The Time Machine. In it, time is described as the fourth dimension, akin to space, and the protagonist travels forward and backward in time using a specially built machine. Interestingly, this idea predates Albert Einstein’s theory of relativity, which would later reshape how we understand space and time.

Einstein’s Contribution: Relativity and Time Dilation

In the early 20th century, Albert Einstein introduced a revolutionary idea through his theory of relativity. He proposed that space and time are interconnected, forming a four-dimensional continuum called space-time. According to his theory, the speed of light (186,000 miles per second) is the ultimate speed limit in the universe. But how does this relate to time travel?
Einstein’s theory states that as you move faster — especially at speeds approaching the speed of light — time slows down relative to someone who is stationary. This phenomenon, known as time dilation, has been proven through various experiments. One famous example involved two synchronized atomic clocks — one placed on Earth and the other onboard a high-speed jet. When the plane returned, the onboard clock showed slightly less time had passed compared to the one on the ground. This demonstrates that, at very high speeds, time passes more slowly.

Astronaut Twins and Time

A notable example of time dilation involved twin astronauts Scott and Mark Kelly. Scott spent 520 days aboard the International Space Station, while Mark spent only 54 days in space. Due to the effects of time dilation, Scott aged slightly less than Mark — by about 5 milliseconds. Though this difference is minuscule, it is real and measurable, showing that time can indeed “bend” under certain conditions.

The GPS Example

Surprisingly, even GPS satellites experience time differently than we do on Earth. These satellites orbit at altitudes of about 20,200 kilometers and travel at speeds of roughly 14,000 km/h. Due to both their speed (special relativity) and weaker gravitational pull at high altitudes (general relativity), time ticks slightly faster for the satellites than for devices on Earth. This discrepancy is corrected using Einstein’s equations to ensure precise positioning. Without these adjustments, GPS systems could be off by several miles each day.

Science Fiction vs. Scientific Reality

Science fiction has long explored imaginative time travel — characters jumping into machines and traveling decades into the future or past. Stories often depict them altering historical events or witnessing the far future. However, there is no scientific evidence that anyone has travelled backward or forward in time in such a dramatic way.

Renowned physicist Stephen Hawking addressed this idea humorously in 2009. He hosted a party for time travellers — but only announced it afterward, reasoning that if time travel were possible, people from the future would show up. No one came. Hawking took this as a tongue-in-cheek sign that backward time travel may not be feasible.

Could Wormholes Be the Key?

Theoretical physics does suggest possibilities like wormholes — shortcuts through space-time. According to Einstein’s equations, these could, in theory, connect distant places and times. A wormhole might allow someone to enter at one point in space and exit at another, potentially in a different time. However, this remains purely speculative. The extreme gravitational forces within black holes or wormholes could destroy anything attempting to pass through.
Moreover, the idea of backward time travel introduces major paradoxes — such as the classic “grandfather paradox,” where someone goes back in time and prevents their own existence. Such contradictions challenge our understanding of causality and logic.

The Limitations of Current Science

At present, building a time machine capable of transporting people backward or forward in time by centuries remains outside the realm of scientific possibility. It’s a concept best enjoyed in novels and films for now. However, subtle forms of time travel — such as time dilation — do occur and have practical implications in science and technology.

While we may not have DeLoreans or TARDISes at our disposal, time travel — at least in small, measurable ways — is a part of our reality. The interplay of speed, gravity, and time demonstrates that our universe is far more flexible than it appears. And who knows? In some distant corner of the cosmos, nature might already be bending time in ways we are only beginning to imagine.

Until then, we’ll keep moving forward — one second per second.

In an intriguing advancement for quantum physics, MIT researchers have captured the first images of individual atoms freely interacting in space — a feat that until now was only predicted theoretically.

The new imaging technique, developed by a team led by Professor Martin Zwierlein, allows scientists to visualize real-time quantum behavior by momentarily freezing atoms in motion and illuminating them with precisely tuned lasers. Their results, published in Physical Review Letters, reveal how bosons bunch together and fermions pair up in free space — phenomena crucial to understanding superconductivity and other quantum states of matter.

“We are able to see single atoms in these interesting clouds of atoms and what they are doing in relation to each other, which is beautiful,” said Zwierlein in a press statement.

Using their method — called “atom-resolved microscopy” — the team was able to trap atom clouds with a loose laser, briefly immobilize them with a lattice of light, and then image their positions via fluorescence. This approach allowed the researchers to observe quantum behaviors at the level of individual atoms for the first time.

The MIT group directly visualized sodium atoms (bosons) bunching together in a shared quantum wave — a vivid confirmation of the de Broglie wave theory — and lithium atoms (fermions) pairing up despite their natural repulsion, a key mechanism underlying superconductivity.

“This kind of pairing is the basis of a mathematical construction people came up with to explain experiments. But when you see pictures like these, it’s showing in a photograph, an object that was discovered in the mathematical world,” said co-author Richard Fletcher in a press statement.

Two other research teams — one led by Nobel laureate Wolfgang Ketterle at MIT, and another by Tarik Yefsah at École Normale Supérieure — also reported similar quantum imaging breakthroughs in the same journal issue, marking a significant moment in the experimental visualization of quantum mechanics.

The MIT team plans to expand the technique to probe more exotic quantum behaviors, including quantum Hall states. “Now we can verify whether these cartoons of quantum Hall states are actually real,” Zwierlein added. “Because they are pretty bizarre states.”

In a major scientific breakthrough, researchers at Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru, India, have developed a novel, cost-effective, metal-free porous organic catalyst that enables efficient hydrogen (H₂) production by harnessing mechanical energy. This innovative work could provide a significant boost to India’s National Green Hydrogen Mission and global efforts toward clean energy.

The team, led by Professor Tapas K. Maji from the Chemistry and Physics of Materials Unit at JNCASR—an autonomous institution under the Department of Science & Technology, Government of India—has designed a donor-acceptor-based covalent-organic framework (COF) that functions as a highly efficient piezocatalyst for water splitting. The findings have been published in the journal Advanced Functional Materials.

“This discovery breaks the traditional notion of solely employing heavy or transition metal-based ferroelectric materials as piezocatalysts for catalyzing water splitting reaction,” said Professor Maji in a press statement.

The COF, constructed using the donor molecule tris(4-aminophenyl)amine (TAPA) and the acceptor molecule pyromellitic dianhydride (PDA), showcases unique ferrielectric (FiE) ordering. Unlike conventional ferroelectric materials, which have limited surface charge and rapidly reach saturation, this FiE structure dramatically enhances the number of charge carriers within the framework’s porous surface. This enables more effective diffusion and interaction of water molecules, resulting in ultra-high hydrogen production yields.

Prof. Umesh V. Waghmare and his team, also at JNCASR, conducted theoretical analyses confirming that the COF’s unusual electronic structure fosters dipolar ordering, leading to lattice instability and FiE behavior. “These FiE dipoles interact with the flexible twisting molecular motion in the material, making them responsive to mechanical pressure,” said Prof. Waghmare. “As a result, the material can generate electron-hole pairs when mechanically stimulated, making it a highly efficient piezocatalyst.”

The research team also includes Ms. Adrija Ghosh, Ms. Surabhi Menon, Dr. Sandip Biswas, and Dr. Anupam Dey from JNCASR, with significant contributions from Dr. Supriya Sahoo and Prof. Ramamoorthy Boomishankar at IISER Pune, and Prof. Jan K. Zaręba from Wrocław University of Science and Technology, Poland.

The innovation offers a promising alternative to traditional oxide-based piezocatalysts and represents a leap forward in the sustainable production of hydrogen fuel. “The utilization of a cost-effective, metal-free system with a high production rate of H2 by harvesting mechanical energy opens up a new route to green H2 based on porous heterogeneous catalysts,” added Prof. Maji.