The science of time travel is real. There is experimental evidence that proves time travel is real. Yet, with but a few exceptions, most of my colleagues in the scientific community avoid discussing or doing serious time travel research. Why is this?

The theory regarding time travel is relatively easy to understand on a technical basis if you have or are pursuing a degree in the physical sciences, or on a conceptual basis, for the layperson. For example, professors teach time dilation (i.e., forward time travel) in undergraduate physics classes. Professors also teach general relativity in both undergraduate and graduate physics classes. The general theory of relativity embodies, along with Einstein’s theory of gravity, the science of time travel to the past. Both the special and general theories of relativity are easy to grasp for a person with the proper scientific background. However, designing and engineering experiments to demonstrate time travel is an extremely difficult task. In fact, building particle accelerators capable of demonstrating even the simplest form of time travel, time dilation, requires the participation of numerous institutions, numerous nations, and a huge financial investment. An example of this is the Large Hadron Collider (LHC), which is the world’s largest high-energy particle accelerator. The European Organization for Nuclear Research (CERN), a collaboration of ten thousand scientists and engineers from over one hundred countries, built the LHC over a ten-year period, 1998 to 2008, at an estimated cost of $9 billion. Scientists hail it as one of the greatest scientific achievements. It is able to perform time dilation experiments, among many other important scientific tasks. However, even with highly sophisticated scientific instruments, research regarding particle acceleration and detection is a difficult endeavor. For example, in 2011, scientists using the Oscillation Project with Emulsion-tRacking Apparatus (OPERA) reported accelerating neutrinos faster than the speed of light, which later proved incorrect and due to faulty cable connections.  The main point is that the apparatus proposed to perform time travel research, even using subatomic particles, is extraordinarily expensive, difficult to build, and difficult to use. The energy required, even when dealing with subatomic particles, is enormous.

In summary, here are the salient elements of the science of time travel:

  • Einstein’s special theory of relativity provides a strong theoretical foundation for forward time travel, which is termed “time dilation.”
  • There is a wealth of scientific data proving time dilation is real and can occur when a frame of reference accelerates near the speed of light, or when a frame of reference is in a strong gravitational field.
  • Even though there is general agreement regarding time dilation, no one has built a machine that enables a human to experience significant time dilation. It is true, however, that people traveling at high speeds, like astronauts, experience some time dilation. To date, the amount of time dilation experienced by any humans is only a small fraction of a second, and not noticeable to the humans involved.
  • Particle accelerators, such as the Large Hadron Collider, are able to accelerate subatomic particles near the speed of light, and time dilation is a measurable effect.
  • Einstein’s general theory of relativity predicts gravitational time dilation. The scientific community generally agrees time dilation occurs in strong gravitational fields.
  • Some solutions to Einstein’s equation of general relativity result in closed timelike curves, which theoretically suggest backward time travel.
  • The scientific community is not in agreement regarding the practicality and reality of backward time travel. In fact, the entire subject of backward time travel is contentious.

The above material is based on my critically acclaimed new book, How to Time Travel, available at