Space & Physics
Is Time Travel Possible? Exploring the Science Behind the Concept
Subtle forms of time travel — such as time dilation — do occur and have practical implications in science and technology.

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.
Society
Ahmedabad Plane Crash: The Science Behind Aircraft Take-Off -Understanding the Physics of Flight
Take-off is one of the most critical phases of flight, relying on the precise orchestration of aerodynamics, propulsion, and control systems. Here’s how it works:

On June 12, 2025, a tragic aviation accident struck Ahmedabad, India when a regional passenger aircraft, Air India flight A1-171, crashed during take-off at Sardar Vallabhbhai Patel International Airport. According to preliminary reports, the incident resulted in over 200 confirmed casualties, including both passengers and crew members, and several others are critically injured. The aviation community and scientific world now turn their eyes not just toward the cause but also toward understanding the complex science behind what should have been a routine take-off.
How Do Aircraft Take Off?
Take-off is one of the most critical phases of flight, relying on the precise orchestration of aerodynamics, propulsion, and control systems. Here’s how it works:
1. Lift and Thrust
To leave the ground, an aircraft must generate lift, a force that counters gravity. This is achieved through the unique shape of the wing, called an airfoil, which creates a pressure difference — higher pressure under the wing and lower pressure above — according to Bernoulli’s Principle and Newton’s Third Law.
Simultaneously, engines provide thrust, propelling the aircraft forward. Most commercial jets use turbofan engines, which accelerate air through turbines to generate power.
2. Critical Speeds
Before takeoff, pilots calculate critical speeds:
- V1 (Decision Speed): The last moment a takeoff can be safely aborted.
- Vr (Rotation Speed): The speed at which the pilot begins to lift the nose.
- V2 (Takeoff Safety Speed): The speed needed to climb safely even if one engine fails.
If anything disrupts this process — like bird strikes, engine failure, or runway obstructions — the results can be catastrophic.

Environmental and Mechanical Challenges
Factors like wind shear, runway surface condition, mechanical integrity, or pilot error can interfere with safe take-off. Investigators will be analyzing these very aspects in the Ahmedabad case.
The Bigger Picture
Take-off accounts for a small fraction of total flight time but is disproportionately associated with accidents — approximately 14% of all aviation accidents occur during take-off or initial climb.
Space & Physics
MIT claims breakthrough in simulating physics of squishy, elastic materials
In a series of experiments, the new solver demonstrated its ability to simulate a diverse array of elastic behaviors, ranging from bouncing geometric shapes to soft, squishy characters

Researchers at MIT claim to have unveiled a novel physics-based simulation method that significantly improves stability and accuracy when modeling elastic materials — a key development for industries spanning animation, engineering, and digital fabrication.
In a series of experiments, the new solver demonstrated its ability to simulate a diverse array of elastic behaviors, ranging from bouncing geometric shapes to soft, squishy characters. Crucially, it maintained important physical properties and remained stable over long periods of time — an area where many existing methods falter.
Other simulation techniques frequently struggled in tests: some became unstable and caused erratic behavior, while others introduced excessive damping that distorted the motion. In contrast, the new method preserved elasticity without compromising reliability.
“Because our method demonstrates more stability, it can give animators more reliability and confidence when simulating anything elastic, whether it’s something from the real world or even something completely imaginary,” Leticia Mattos Da Silva, a graduate student at MIT’s Department of Electrical Engineering and Computer Science, said in a media statement.
Their study, though not yet peer-reviewed or published, will be presented at the August proceedings of the SIGGRAPH conference in Vancouver, Canada.
While the solver does not prioritize speed as aggressively as some tools, it avoids the accuracy and robustness trade-offs often associated with faster methods. It also sidesteps the complexity of nonlinear solvers, which are commonly used in physics-based approaches but are often sensitive and prone to failure.
Looking ahead, the research team aims to reduce computational costs and broaden the solver’s applications. One promising direction is in engineering and fabrication, where accurate elastic simulations could enhance the design of real-world products such as garments, medical devices, and toys.
“We were able to revive an old class of integrators in our work. My guess is there are other examples where researchers can revisit a problem to find a hidden convexity structure that could offer a lot of advantages,” Mattos Da Silva added.
The study opens new possibilities not only for digital content creation but also for practical design fields that rely on predictive simulations of flexible materials.
Space & Physics
This Sodium-Fuelled Clean Energy Breakthrough Could Electrify Aviation and Shipping
The innovation offers more than triple the energy density of today’s lithium-ion batteries — potentially clearing a major hurdle for electric-powered aviation, rail, and maritime travel

A new type of fuel cell developed by MIT researchers could represent a pivotal breakthrough in the race to decarbonize heavy transportation. Designed around liquid sodium metal, the innovation offers more than triple the energy density of today’s lithium-ion batteries — potentially clearing a major hurdle for electric-powered aviation, rail, and maritime travel.
Unlike traditional batteries that require time-consuming recharging, this system operates like a fuel cell that can be refueled quickly using liquid sodium — a cheap, abundant substance derived from salt. The technology, which uses air as a reactant and a solid ceramic electrolyte to facilitate the reaction, was tested in lab prototypes and demonstrated energy densities exceeding 1,500 watt-hours per kilogram — a level that could enable regional electric flight and clean shipping.
“We expect people to think that this is a totally crazy idea,” said Professor Yet-Ming Chiang, lead author and Kyocera Professor of Ceramics, in a media statement. “If they didn’t, I’d be a bit disappointed because if people don’t think something is totally crazy at first, it probably isn’t going to be that revolutionary.”
Chiang explained that current lithium-ion batteries top out at around 300 watt-hours per kilogram — far short of the 1,000 watt-hours needed for electric aircraft to become viable at scale. The new sodium-based cell meets that benchmark, which could enable 80% of domestic flights and drastically reduce aviation’s carbon footprint.
Moreover, the sodium-fueled system offers environmental benefits beyond zero emissions. Its chemical byproduct, sodium oxide, reacts spontaneously in the atmosphere to capture carbon dioxide and convert it into sodium bicarbonate — better known as baking soda — which may help counteract ocean acidification if it ends up in marine environments.
“There’s this natural cascade of reactions that happens when you start with sodium metal,” Chiang said. “It’s all spontaneous. We don’t have to do anything to make it happen, we just have to fly the airplane.”
The team has already created two functioning lab-scale prototypes: one vertical and one horizontal model. In both, sodium gradually reacts with oxygen from air to generate electricity, and a moist air stream improves the process by allowing liquid byproducts to be expelled more easily.
Karen Sugano, one of the MIT doctoral students on the project, noted, “The key was that we can form this liquid discharge product and remove it easily, as opposed to the solid discharge that would form in dry conditions,” she said in a media statement.
The researchers have founded a startup, Propel Aero, housed in MIT’s startup incubator The Engine, to scale the technology. Their first commercial goal: a brick-sized fuel cell capable of powering a large agricultural drone — expected to be ready within a year.
Chiang emphasized the economic and safety benefits of using sodium, which melts just below 100°C and was once mass-produced in the U.S. for leaded gasoline production. “It reminds us that sodium metal was once produced at large scale and safely handled and distributed around the U.S.,” he said.
Critically, the fuel cell design also avoids many safety concerns of high-energy batteries by physically separating the fuel and oxidizer. “If you’re pushing for really, really high energy density, you’d rather have a fuel cell than a battery for safety reasons,” Chiang said.
By reviving and reimagining sodium-metal chemistry in a practical, scalable form, the MIT team may have lit the path toward clean, electrified transportation systems — from the skies above to the oceans below.
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