(Monica Tavarez Frias, Saint Patrick School of Santo Domingo, Dominican Republic)
Introduction
What if the key to time travel isn’t hidden within the depths of our imagination, but rather in the vast, unexplored reaches of space? Science fiction has long immersed us with stories of time travel and paradoxes, but recent advancements in physics and quantum physics reveal that time travel is not as fictional as we once imagined. It is the cosmos itself, with black holes, wormholes, and relativistic events that may be the solution we are searching for (see Fig. 1). In space lies the extreme conditions needed to bend time — with consequences which may already exist (NASA Space Place2020).
Fig 1 Artist’s conception of clocks ticking at different rates as they pass through a wormhole. (Credits: Adi Foord [U. Maryland Baltimore County], ragio5 via Pixabay)
Ideas Related to Time Travel
Albert Einstein’s theory of relativity is the foundation of time travel. Based on his “Special Theory of Relativity”, time is not absolute, it varies with the speed of the observer. This theory of time dilation has been verified experimentally. Astronauts on the International Space Station, for instance, age slightly less than people on Earth due to their high velocity relative to the planet. The faster you travel, the slower time passes for you in contrast to one who is stationary (ScienceReady 2025).
Another of Einstein’s great theories is the theory of “General Relativity” in which he expands on this principle, demonstrating that gravity also distorts time. The more gravitational field there is, the slower time moves. This has been proven with atomic clocks at different altitudes; clocks close to Earth’s surface, where gravity is stronger, move slower than clocks at higher altitudes. This theory suggests that strong gravitational fields such as those around black holes can be utilized to manage time (Bartels et al. 2024; Matton 2025).
Among further theoretical ideas, there are wormholes and cosmic strings that offer other avenues for time travel. Wormholes, if they exist at all, would be tubes or shortcuts through space-time that would allow for travel instantaneously across great distances or even through different points in time. Cosmic strings—hypothetical filaments of unimaginable density that spread across the universe—would warp space-time sufficiently to enable the formation of closed timelike curves, theoretically allowing for travel through time (Editverse.com; Folger 2015).
The most promising time travel mechanism is the black hole. General Relativity dictates that a Kerr black hole (a rotating black hole) would give rise to a stable, time traversable loop. If something orbits within close enough proximity to such a black hole but not inside it, time for the object would slow down enormously concerning the outside world. That would mean that the traveler would experience a few years, while outside, time would pass as centuries.
The second possibility is wormholes. Abstract as it may be now, it is theoretically possible for a wormhole to connect two points in space-time. If one end of the wormhole was accelerated to close to the speed of light and then brought back, the time dilation would make one end older than the other and thus allow some form of time travel. But it would be contingent upon exotic matter with negative energy density, which has not yet been discovered (Folger 2015).
The expansion of the universe itself can also be a method of time travel. Physicists have proposed that modifying the accelerated expansion of the universe can yield pathways through time. We can travel through various periods if we are capable of accessing the expansion and contraction of space-time (Alcubierre 2000).
Along with other possibilities, recent advances in particle physics and quantum theory suggest the possibility of microscopic time travel. Quantum entanglement, for example, suggests that particles can influence each other instantly across vast distances, something that would defy the conventional understanding of time. Some scientists believe that research into such quantum events can yield new means of controlling or manipulating time (Starr 2023).
Challenges to Time Travel
Despite such enticing prospects, there are serious obstacles. Arguably the best-known of them is the grandfather paradox (see Fig. 2): if you travel back in time and alter the past—e.g., prevent your grandfather from meeting your grandmother—do you cease to exist? Certain theories, like the many-worlds interpretation of quantum theory, suggest that time travel would yield multiple timelines rather than altering one fixed history (Folger 2015).
Fig. 2 Graphical description of the Grandfather Paradox. (Credit: BYJUS.com)
And another paradox, the paradox of the bootstrap, challenges self-caused objects or information. If one were to go back in time and give the complete works of Shakespeare to Shakespeare himself, who wrote them then? Paradoxes such as these challenge our most basic concepts of causality and the passage of time (BYJUS.com 2023).
Technological limitations are also one of the major hurdles. Energy required to stabilize and create a wormhole or to operate with black holes is far beyond our capabilities. Negative energy that would stabilize a wormhole is theoretical as of now with only tiny-scale quantum fluctuations indicating it might be present. Even if it were achievable to build a functioning time machine, stabilizing and piloting it would be another colossal feat (Folger 2015). Also, the impact of time travel on the human body is not understood. Would prolonged exposure to high gravitational force or relativistic velocities affect the functioning of the brain, cellular structure, or even consciousness? We cannot forecast the biological dangers of time travel without extensive (and expensive) research.
Philosophically, time travel creates profound problems. Would we ever use it if it were possible? The potential for disaster—changing the past, ethical dilemmas, and unintended ripple effects—would be too great. And if time travel is possible, then where are all the time travelers from the future that we should have noticed by now? Others have suggested that advanced civilizations have strict rules against altering the past, or that time travel would only be achieved in ways that do not interfere with recorded events. This latter condition is known as the Self-Consistency Principle (Carlini 1995; Thompson 2024).
Current State of Time Travel Research
Although time travel remains conjectural at this point in time, studies of astrophysics and quantum physics keep broadening our understanding of what can be achieved. Black hole research has particularly progressed significantly, with the Event Horizon Telescope providing the first ever photograph of the event horizon of a black hole (Event Horizon Telescope 2022). These observations are continuing to refine our understanding of gravity’s effect on space-time and potentially have future uses for time manipulation.
Similarly, advances in particle physics, such as experiments at the Large Hadron Collider, have the potential to expose new aspects of quantum physics that redefine our understanding of time. Discovery of new particles or new forces has the potential to provide us with the missing pieces of information to decipher the mysteries of time travel.
One of the topics of research is the identification of naturally occurring cosmic events that are potential portals to time. If wormholes or cosmic strings do exist, their detection and analysis would be of tremendous worth in understanding their composition and potential uses (Folger 2015; Editverse 2024).
As of now, the most potential for unlocking it is in space. Gravity, speed, and the bending of space-time suggest that the universe has the potential for time manipulation. Black holes, wormholes, and the universe itself are potential keys to travel through time if we can overcome the massive scientific and philosophical challenges. The potential of time travel, if it ever became a reality, would be massive. It would revolutionize exploration, history, and even the fate of civilizations. But with great power would come great responsibility. If ever humankind were to develop the capability of traveling through time, the question would be: How would we exercise this power—to explore, to learn, or to alter the past? And in doing so, would we preserve the timeline we have come to know — or create one beyond our wildest imaginations?
References
Alcubierre, M. (2000). “The warp drive: Hyper-fast travel within general relativity.” Classical and Quantum Gravity, Vol. 11, p. 5.
DOI: http://dx.doi.org/10.1088/0264-9381/11/5/001 https://www.researchgate.net/publication/1963139_The_Warp_Drive_Hyper-fast_Travel_Within_General_Relativity
Bartels, M., Tillman, N. T., & Dutfield, S. (2024, October 29). “What is the theory of general relativity? Understanding Einstein’s space-time revolution.” Space.com. https://www.space.com/17661-theory-general-relativity.html
BYJUS.com. (2023, April 7). Grandfather Paradox – Time travel, Bootstrap Paradox, FAQs. BYJUS. https://byjus.com/physics/grandfather-paradox/
Carlini, A., Frolov, V. P., Mensky, M. B., Novikov, I. D., & Soleng, H. H. (1995). “Time machines: The principle of self-consistency as a consequence of the principle of minimal action.” CERN/NORDITA. https://cds.cern.ch/record/284146/files/9506087.pdf
Editverse “Expert”. (2024, September 15). “Interstellar Shortcuts: Scientists’ breakthrough in wormhole creation” https://editverse.com/wormhole-theory/
Event Horizon Telescope (2022, May 12). “Astronomers reveal first image of the black hole at the heart of our Galaxy.”https://eventhorizontelescope.org/blog/astronomers-reveal-first-image-black-hole-heart-our-galaxy
Folger, T. (2015, December 1). “Can time travelers reach the past via wormholes?” Scientific American. https://www.scientificamerican.com/article/can-time-travelers-reach-the-past-via-wormholes/
Matton, B. (2025, May 21). “Black Holes,” NASA Science. https://science.nasa.gov/universe/black-holes/
NASA Space Place (2020, April) “Is time travel possible?” NASA Space Place – NASA Science for Kids. https://spaceplace.nasa.gov/time-travel/en/
Science Ready. (2025). “Special Relativity: Time dilation & Length Contraction.” HSC Physics, https://scienceready.com.au/pages/time-dilation-and-length-contraction?srsltid=AfmBOoquyq8UZlt9W3LBFBpPYOlHkj4-DsRM5f7B_dRmnTRYlyXERYnt
Starr, M. (2023, October 13). “Time travel simulations can solve impossible problems, physicists say.” ScienceAlert. https://www.sciencealert.com/time-travel-simulations-can-solve-impossible-problems-physicists-say
Thompson, E. (2024, January 1). “Understanding the Novikov self-consistency principle: Beginner’s guide.” TimeQuiver. https://timequiver.com/blog/time-travel-theories/novikov-self-consistency-principle/understanding-novikov-self-consistency-principle-beginners-guide
Monica Taveras Frias wrote this essay as an 11th grade student at the St. Patrick School of Santo Domingo in Santo Domingo, the capital city of the Dominican Republic. She credits her science teacher, Marleshka Maradei, as a reference.