Tag Archives: gravitational time dilation

Interior view of the Fermi particle accelerator with its large orange beamline and surrounding machinery.

Evidence of time travel to the future (time dilation)

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When we talk about time travel to the future, in scientific terms we are talking about time dilation. What is time dilation? It is a scientific fact that time moves slower for any mass accelerated near the speed of light. If that mass were a clock, for example, the hands of the clock would appear to be moving slower than a clock in the hand of an observer at rest. That phenomenon is termed time dilation. Below are the classic experiments that have demonstrated time travel to the future (time dilation) is real.

Velocity time dilation experimental evidence:

Rossi and Hall (1941) compared the population of cosmic-ray-produced muons at the top of a six-thousand-foot-high mountain to muons observed at sea level. A muon is a subatomic particle with a negative charge and about two hundred times more massive than an electron. Muons occur naturally when cosmic rays (energetic-charged subatomic particles, like protons, originating in outer space) interact with the atmosphere. Muons, at rest, disintegrate in about 2 x 10-6 seconds. The mountain chosen by Rossi and Hall was high. The muons should have mostly disintegrated before they reached the ground. Therefore, extremely few muons should have been detected at ground level, versus the top of the mountain. However, their experimental results indicated the muon sample at the base experienced only a moderate reduction. The muons were decaying approximately ten times slower than if they were at rest. They made use of Einstein’s time dilation effect to explain this discrepancy. They attributed the muon’s high speed, with its associated high kinetic energy, to be dilating time.

In 1963, Frisch and Smith once again confirmed the Rossi and Hall experiment, proving beyond doubt that extremely high kinetic energy prolongs a particle’s life.

With the advent of particle accelerators that are capable of moving particles at near light speed, the confirmation of time dilation has become routine. A particle accelerator is a scientific apparatus for accelerating subatomic particles to high velocities by using electric or electromagnetic fields. The largest particle accelerator is the Large Hadron Collider, completed in 2008.

In 1977, J. Bailey and CERN (European Organization for Nuclear Research) colleagues accelerated muons to within 0.9994% of the speed of light and found their lifetime had been extended by 29.3 times their corresponding rest mass lifetime. (Reference: Bailey, J., et al., Nature 268, 301 [1977] on muon lifetimes and time dilation.) This experiment confirmed the “twin paradox,” whereby a twin makes a journey into space in a near-speed-of-light spaceship and returns home to find he has aged less than his identical twin who stayed on Earth. This means that clocks sent away at near the speed of light and returned near the speed of light to their initial position demonstrate retardation (record less time) with respect to a resting clock.

Gravitational time dilation experimental evidence:

In 1959, Pound and Rebka measured a slight redshift in the frequency of light emitted close to the Earth’s surface (where Earth’s gravitational field is higher), versus the frequency of light emitted at a distance farther from the Earth’s surface. The results they measured were within 10% of those predicted by the gravitational time dilation of general relativity.

In 1964, Pound and Snider performed a similar experiment, and their measurements were within 1% predicted by general relativity.

In 1980, the team of Vessot, Levine, Mattison, Blomberg, Hoffman, Nystrom, Farrel, Decher, Eby, Baugher, Watts, Teuber, and Wills published “Test of Relativistic Gravitation with a Space-Borne Hydrogen Maser,” and increased the accuracy of measurement to about 0.01%. In 2010, Chou, Hume, Rosenband, and Wineland published “Optical Clocks and Relativity.” This experiment confirmed gravitational time dilation at a height difference of one meter using optical atomic clocks, which are considered the most accurate types of clocks.

This information is from my new book, How to Time Travel, available in both a Kindle and paperback edition on Amazon. To browse the book free and read the reviews click here: How to Time Travel.

A silhouette of a person with a clock face behind them, symbolizing the concept of time and human existence.

Theoretical Foundations for Time Travel (Why time travel is possible!)

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This post is based on material from chapter 1 of my new book, How to Time Travel.

Einstein’s special and general theories of relativity underpin the science of time travel. They are briefly presented here as theoretical evidence that time travel is real. In addition, Del Monte’s existence equation conjecture is presented as theoretical evidence that time travel is real.

1. Einstein’s special theory of relativity—The scientific community considers the special theory of relativity the “gold standard” of scientific theories. It has withstood over one hundred years of experimental verification. In addition to yielding the most iconic scientific equation of all time, E = mc2, it also gave us our first insight into the scientific nature of time and predicted time dilation, both conceptually and mathematically. Time dilation is the experimentally verifiable difference of elapsed time between two events as measured by observers, when either one or both observers are moving relative to each other at a velocity near the speed of light. It is an experimental fact that the second hand on a clock moving at a velocity close to the speed of light moves slower than a clock at rest. Time dilation is real and implies forward time travel. For example, if you board a spacecraft capable of traveling at 650 million miles per hour, a one-day journey measured by a clock onboard the spacecraft would be equivalent to the passage of one year on Earth. Time dilation experiments are routinely performed using particle accelerators, which we will discuss later in this chapter.

2. Einstein’s general theory of relativity—Numerous aspects of the general theory of relativity have been verified. For our purposes regarding time travel, it is important to focus on only two:

* Gravitational time dilation—Gravitational time dilation suggests that two observers differently situated from gravitational masses will observe time differently. For example, a clock closer to the Earth will run slower than a clock farther from the Earth. The stronger the gravitational field, the greater the time dilation. This has been experimentally verified using atomic clocks, and we will discuss the results later in this chapter.

* Closed timelike curves—There are numerous solutions to Einstein’s equations of general relativity that delineate the world line of a particle is closed, returning to its starting point. In the general theory of relativity, the world line is the path the particle traverses in four-dimensional spacetime. For example, when the particle starts out, it has four coordinates, three dimensional coordinates and one temporal coordinate. Here is a simple analogy. You are in a specific place, definable by three spatial coordinates, reading this book at a specific time, a temporal coordinate. If the world line of a particle returns to its starting point, the particle is said to have returned to its past, suggesting backward time travel is theoretically possible. However, to date, we have not been able to experimentally verify that this aspect of Einstein’s general theory of relativity is true. As previously discussed, there is evidence that the “arrow of time” can be twisted, and that events in the future can influence past events. However, this is not conclusive experimental proof that backward time travel is possible.

3. Del Monte’s existence equation conjecture—In summary, the existence equation conjecture is derived from Einstein’s special theory of relativity and predicts that a mass requires energy to move in time. If additional positive energy is added to the mass, for example, by accelerating it in a particle accelerator and increasing its kinetic energy, the mass will move more slowly in time. I interpret this as the fundamental explanation of time dilation. An interesting aspect of the existence equation conjecture is that it suggests adding negative energy to a mass will cause the mass to move backward in time. Since today’s science has been unable to produce and manipulate negative energy, this last point has not been experimentally verified. (Note: An entire chapter is devoted to explaining the existence equation conjecture in the referenced source, How to Time Travel)

Source: From chapter 1 of How to Time Travel: Explore the Science, Paradoxes, and Evidence (September 2013), Louis A. Del Monte (Amazon)

Image: Book Cover How to Time Travel