Possible Ways Time Travel Can Be Achieved (Continued)

1.) Infinite Cylinder 

A mechanism proposed by Astronomer Frank Tipler where 10 times the sun's mass would be rolled into a long and dense cylinder. "After spinning this up a few billion revolutions per minute, a spaceship nearby – following a very precise spiral around this cylinder – could get itself on a 'closed, time-like curve', according to the Anderson Institute." 

2.) Black Holes 

According to physicist Stephen Hawking, a ship moving rapidly around a black hole would experience just half the time everyone on Earth was experiencing. However, the travelers would need to travel around the speed of light to achieve this type of time travel. 

3.) Cosmic Strings 

Cosmic strings are "narrow tubes of energy stretched across the entire length of the ever-expanding universe." Left over from early cosmos, these strings are said to contain massive amounts of mass and could potentially wrap the space-time around them. In theory, "The approach of two such string parallel to each other would bend space-time so vigorously and in such a particular configuration that might make time travel possible." 

4.) Time Machines 

Research of time machines involves creating something known as a closed time-like curve, in which space-time is bent so far that time lines turn back on themselves to form a loop. To achieve this, an exotic form of matter with "negative energy density" would be needed, which is said to have numerous bizarre properties like moving in the opposite direction of normal matter when pushed. If this matter did exist, the quantity available would be far too small for time machine construction. Time machines may also be possible without the use of this exotic matter. "The work begins with a doughnut-shaped hole enveloped within a sphere of normal matter. Inside this doughnut-shaped vacuum, space-time could get bent upon itself using focused gravitational fields to form a closed time-like curve. To go back in time, a traveler would race around inside the doughnut, going further back into the past with each lap."  


https://www.space.com/21675-time-travel.html

Time Travel in Science Fiction

1.) Time travel by moving through higher dimensions 

In "Interstellar," a vessel where time is represented as a dimension of space, called a "tesseract," was created by advanced beings which allows Cooper to move in one direction to see the past and the other direction to see the future. 

2.) Traveling the space-time vortex 

"Doctor Who's" TARDIS (Time And Relative Dimension In Space) travels through an extra-dimensional vortex to move to different points in space and time. Time passes normally within the TARDIS. 

3.) Instantaneous time jumping 

In "The Girl Who Leapt Through Time," a 2006 anime, Makoto Konno discovers a device that enables her to jump through time. There is no passage of time for the travel unlike in "Dr. Who."  

The DeLorean from "Back to the Future" is also an example of instantaneous time jumping. 

4.) Time traveling while standing still 

In the "Harry Potter" series, Hermione's Time-Turner, as well as H.G. Wells' machine in his novel, "The Time Machine," both work by moving the travelers forward and backward in the time dimension while keeping them in one spot in space. 

5.) Slow Time Travel 

"In the 2004 film 'Primer,' the traveler stays within a box for 1 minute for each minute of time travel. To go back 24 hours, 24 hours must be spent in the box. The traveler can go back no further than when the time machine was switched on. On arrival, two versions of the traveler exist: the one who time-traveled and the one who has not yet done so" 

6.) You can't go home again 

A time-displacement machine projects a traveler to a point in time in the "Terminator" franchise however it does not allow the traveler to return to the origin point. 


https://www.space.com/21675-time-travel.html

Time Travel Video

After watching this video, you can decide for yourself whether or not time travel is possible.