Hidden "scars" of the Universe may reveal the secrets of time travel: findings by physicists.

If physicists can confirm the existence of cosmic strings, they could help create the Holy Grail of physics, which is a theory of everything that unifies quantum mechanics and Einstein's theory of relativity. Furthermore, cosmic strings might allow for time travel, according to BGR.

What are cosmic strings?

Theories describing cosmic strings suggest that these structures are thinner than an atomic nucleus and take the form of a very long, thin thread. Physicists believe that cosmic strings are long tubes that either stretch infinitely or loop back on themselves. Despite their extreme thinness, a cosmic string could possess the mass of tens of thousands of stars and would gradually compress over time, emitting gravitational waves during oscillations. It is proposed that a typical loop of a cosmic string might measure 10-20 light-years in length.

Theoretical physicists suggest that there are two types of cosmic strings. The first are called cosmic superstrings and originate from string theory. This theory posits that the fundamental particles of the universe are vibrating strings, and it represents an attempt to create what is known as a theory of everything. Superstrings could stretch across the cosmos, providing clues about the structure of reality and possibly holding the key to time travel as well.

The second type of cosmic strings, according to theory, is a relic structure left over from the formation of the early universe. They are sometimes referred to as the hidden scars of the universe. Physicists believe they formed during the very first moments after the Big Bang when the four fundamental forces of nature—electromagnetism, gravity, and the strong and weak interactions—decoupled. As the universe began to cool, unique cracks in space emerged, known as cosmic strings.

Is time travel possible?

Astrophysicist J. Richard Gott from Princeton University believes that cosmic strings could provide the key to time travel. According to the scientist, two cosmic strings moving at speeds close to the speed of light could theoretically create a loop in spacetime. In this way, they would form a sort of wormhole.

Einstein's general theory of relativity allows for the existence of loops in time, which may enable time travel. This is because spacetime can curve to the point of closing back on itself and creating a loop.

Gott believes that cosmic strings can warp spacetime, creating shortcuts within it. This is what a wormhole is. If people on a spaceship traveled between two planets, and a cosmic string lay in between, it could allow them to reach another planet incredibly quickly. Traveling this way at speeds close to the speed of light would enable them to arrive at their destination faster than a beam of light traveling directly between the two planets. This means that travelers arriving at their destination could witness themselves just getting ready to depart.

According to Gott, two cosmic strings moving in opposite directions and intersecting with each other warp spacetime in such a way that it creates a loop in time. By traveling along the two strings, one could potentially return to the past.

A theory that describes all of physics

However, detecting cosmic strings is very challenging. Their extreme density should warp spacetime, creating a gravitational lensing effect that could cause duplication of images of galaxies. But these strings may be lighter than expected, making such lensing impossible.

Thus, Gott believes that observing gravitational microlensing events, where a passing string can temporarily double the brightness of a star, will help in their detection. The astrophysicist also suggests that finding cosmic strings could aid in creating a Grand Unified Theory, which describes all known physics in the universe as a cohesive whole.