Wormholes

Traveling at the speed of light, which is 299,792,458 meters per second, a spaceship would take more than four years to cover the distance to the nearest star system, Alpha Centauri, and billions of years to observe the known universe. While humans have been technologically advanced, the vastness of the universe has still presented a barrier to them. However, a wormhole, a shortcut through space-time, does offer a solution to this cosmic challenge. The theory of wormholes is based on the theory of general relativity postulated by Einstein, where gravity turns out to be a curvature caused by massive objects in space-time.

In 1935, Albert Einstein proposed that there might be bridges to connect two points in spacetime, now known as Einstein-Rosen bridges or wormholes. These could be used as tunnels, allowing almost instantaneous travel over cosmological distances. An easy way to think of this is to think of  folding a piece of paper so that two distant points meet, removing the space between them. If wormholes exist, that would explain the unknown interstellar travels, thus changing humankind's comprehension of the universe. It would let crossing two vast distances in just an instant possible, but such travel remains open to question. The stabilization of the wormhole would require unknown matter substances with negative energy density against the great gravitational forces that would collapse it. Theoretically, the unknown matter could be a form of matter which could support the wormhole and keep it open, but finding it is beyond our technological capabilities.

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Another related question is the appearance of a wormhole. In the movie Interstellar, a wormhole near Saturn was depicted as a shining three-dimensional sphere that distorts the stars behind it. This visualization is in agreement with a few predictions from scientists: A wormhole would show as a glowing, spherical distortion. Inside, the folded space-time can enable the passenger to experience some supernatural experiences. Wormholes bring into the realm of time travel a number of very bizarre paradoxical issues. If the two mouths of a wormhole were to move relative to each other, then time dilation effects might send one mouth into the past and the other into the future. Such a scenario could allow several so-called grandfather paradoxes: going back in time and killing one's own grandfather would eliminate my existence. These paradoxes question our comprehension of physics and hint that if wormholes do exist, they must be restricted against such scenarios.

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With all these challenges, there remains immense potential for scientific discovery in wormholes. In fact, they might just be the way to explore other galaxies, black holes, and even parallel universes that would otherwise be totally out of reach. They might provide great insight into the basic nature of space, time, and gravity and lead to the unification of general relativity and quantum mechanics. Research on wormholes is thus one of the fastest-developing branches of theoretical physics with quite new possibilities of checking the laws of the universe. Though their existence has not been proved, and it is not even known whether they could ever serve any practical use, they fascinate scientists. Whether a theoretical concept or someday actual, wormholes are at the service of expanding our imagination on how the universe might work.

Image credit: New Atlas

References

• Einstein, Albert, and Nathan Rosen. "The Particle Problem in the General Theory of Relativity." Physical Review, vol. 48, no. 1, 1935, pp. 73–77.

• Hawking, Stephen. A Brief History of Time. Bantam Books, 1998.

• Thorne, Kip S. The Science of Interstellar. W.W. Norton & Company, 2014.

• Morris, Michael S., and Kip S. Thorne. "Wormholes in Spacetime and Their Use for Interstellar Travel: A Tool for Teaching General Relativity." American Journal of Physics, vol. 56, no. 5, 1988, pp. 395–412.