Time Travel

Time and Space Continum

Time/Space continuum: Time is defined as being the fourth dimension of our universe. The other three dimensions are of space, including up-down, left-right and backward-forward. Time cannot exist without space, and likewise, space cannot exist without time. This interconnected relationship of time and space is called the spacetime continuum, which means that any event that occurs in the universe has to involve both space and time.

4th dimension: Time is the Fourth Dimension of our Universe.

Black Holes/Worm Holes

Most theories of time travel don't rely on machines at all. Instead, time travel will likely be done by way of natural phenomena that will transport us instantly from one point in time to another.

These space phenomena, which we are not even sure exist, include:

Rotating black holes: When stars that are more than four times the mass of our sun reach the end of their life and have burned up all of their fuel, they collapse under the pressure of their own weight. This implosion creates "black holes," which have gravitational fields so strong that even light cannot escape. Anything that comes in contact with a black hole's event horizon will be sucked in and possibly transported to a different dimension.

Wormholes:Wormholes, also called Einstein-Rosen Bridges, are considered to have the most potential for time travel if they do exist. Not only could they allow us to travel through time, they could allow us to travel many light-years from Earth in only a fraction of the amount of time that it would take us with conventional space travel methods.

Wormholes are considered possible based on Einstein's theory of relativity, which states that any mass curves spacetime. Worm holes fold space and time.

Physics in Time Travel

As we discussed earlier, the theory of relativity states that as the velocity of an object nears the speed of light, time slows down. Scientists have discovered that even at the speeds of the space shuttle, astronauts can travel a few nanoseconds into the future. To understand this, picture two people, person A and person B. Person A stays on Earth, while person B takes off in a spacecraft.

At takeoff, their watches are in perfect sync. The closer person B's spacecraft travels to the speed of light, the slower time will pass for person B (relative to person A). If person B travels for just a few hours at 50 percent the speed of light and returns to Earth, it will be obvious to both people that person A has aged much faster than person B.

This difference in aging is because time passed much faster for person A than person B, who was traveling closer to the speed of light. Many years might have passed for person A, while person B experienced a time lapse of just a few hours

Mary Doodles' Time Travel

Self-consistency Principle

Because the timeline is totally fixed, any actions taken by the time traveler was part of history all along. Therefore it is impossible for the time traveler to"change" history in any way.

New Physical Laws

New physical laws take effect which thwart any attempt to change the past. (For instance, rejecting time travelers and/or sending them back to their own time.)

Easy to Change

History is fairly easy to change and can impact the time traveller, the world or both.

Chaotic Time

History is EXTREMELY easy to change and the timeline is so sensitive that even minor changes have huge consequences. ("The Butterfly Effect")

Resistant Change

History is somewhat resistant to change. Typically the more important the event/consequences, the more resistant to change. Small, trivial events can be readily changed but large ones take great effort or are rejected.

Parallel Universe

There are parallel universes that already exist and it is only possible to travel between them, not our own.

Divergent Timelines

There are an infinite number of possible histories because time travel actually creates each new timeline the moment that the traveller arrives in the past.

Causal Loop Paradox

A causal loop is a paradox of time travel that occurs when a future event is the cause of a past event, which in turn is the cause of the future event. Both events then exist in spacetime, but their origin cannot be determined.

Is Time Travel Possible?