Humans’ perception of space has commonly been embodied in the three-dimensional model of length width and depth. However, a fourth aspect comes into play from an individual’s journey from the cradle to the grave. This aspect is time. Time has a great impact on the existence of humans in space and is considered to be the most precious yet most perishable resource in life. This has since time memorial, stirred desires to be able to manipulate this fourth aspect in order to increase the periodical dominance of man over space. In 1985 H.G Wells published a work of fiction titled “The Time Machine” which introduced the concept of time travel.( Morris, Richard) This concept proposes that it is possible for man to move between two different points in time. However, Albert Einstein’s special theory of relativity laid foundation for the theoretical possibility of travelling through time. (“How Time Travel Will Work”) With time, time travel has developed from a mere fantasy to an actual projection of future capabilities. This has been seen through hefty investment in numerous experiments designed and executed by different physicists and scientists in an attempt to explore any future prospects in the application of time travel. These experiments, though not fully successful, have provided significant breakthroughs in man’s understanding of time and space. This research paper highlights an experiment to justify the hypothesis that time travel will most likely be part of the future.
The experiment documented in this research paper is based on Albert Einstein’s theory of special relativity. This theory involves the physics of bodies moving at the speed of light. At these speeds, Newton’s laws of motion need to be modified. (“Einstein’s Theory Passes a Space ‘Laboratory’ Test.”) This theory suggests that if a man was to travel away from his twin at a speed that is a similar to that of light and then returns some time later still at the speed of light he will find that his twin has aged more than him. This difference in time in relation to special relativity is known as time dilation. This research paper highlights two experiments carried out by Ricky K. C. Au, Katsumi Watanabe and Fuminori Ono. These experiments prove their hypothesis that the time dilation induced by the motion of an object is based on spatiotopic positions rather than retinotopic positions. (Ricky K. C. Au) Retinotopic motion involves the motion of the retina with no physical motion while spatiotophic motion involves physical motion of observers with no motion of the retina. This paper focuses more on their first experiment to indicate why the reality of time travel seems probable in the near future.
Their first experiment investigated time dilation under the motion of an object without any movement of the eyes. This experiment involved eleven paid observers from the University of Tokyo; eight of whom were females. One of the researchers, authors also participated voluntarily making a total of 12 observers. All the observers had normal or corrected vision. The stimuli used in this experiment were programmed in MATLAB and viewed on a CRT monitor at a rate of 100 Hz. These monitors had a resolution of 800 × 600 pixels and were controlled by a Windows XP operating system. The observers were asked to view the stimuli from a quiet room that was dimly lit and which was 60 cm away from the stimuli. On the monitor, all stimuli appeared white against a black background. The target on the screen was circular.
In each experiment, there was a stimulus and another stimulus to compare to it. These two were presented to the observers at separate intervals of time. At the beginning of each trial, a fixation stimulus was constantly at the center of the screen. Observers were asked to start the observation of the stimulus by pressing the space bar on the keyboard of the computer. After 1000 ms, the target stimulus appeared 4.5330 below for the duration of 1000 ms. After this period, a comparison stimulus was then presented to the observers for a random duration of 800-1200 ms. In the static state, the stimulus used for comparison appeared at 4.5330 above the point of fixation without any movement. On the motion, the target circle appeared at the same vertical distance above the point of fixation but moved horizontally to the left or right of the point of fixation at a constant speed of 11.334 degrees per second. A random variation of -0.136 0, 00 and +0.136 0 for the starting and ending positions of the moving stimulus. This was done so that the observer being tested would not become accustomed to the identical stimulus within the same duration of time. As a result of this change in position, the starting distances appeared to shift to the right and left of the point of fixation with variation of time in milliseconds.
After the comparison stimulus had been presented, the observer was asked to judge whether the comparison or reference stimulus had appeared for a longer duration of time by pressing the right arrow key (for the comparison stimulus) and the left arrow key (for the reference stimulus) on the keyboard of the computer. In this experiment the duration conditions were tested three times, the motion conditions were tested two times and the Starting-ending positions were tested three times. These were presented in a pseudorandom order with a total of 6 repetitions. This totaled up to 108 trials. This experiment took an average of ten to fifteen minutes to complete.
A control experiment was also set up to observe if the effect was as a result of novelty caused by the movement of the comparison stimulus. This control experiment involved a similar number of trials but the reference stimulus (at 1000 ms) was in constant motion across the monitor from 5.6670 to the left and right of the fixation. All of the observers performed the control or main experiment in a counter-balanced order with a 5-minute interval between the two experiments.
The proportion of trials in which the duration of the target stimulus was thought to be longer than the duration of the reference stimulus was then analyzed for the moving and static condition, averaged for the dozen (observers) and plotted against the three durations tested.
Experiment 1 [(A) stationary reference; (B) moving reference control experiment]; error bars represent SEM. (Ricky K. C. Au)
INCLUDEPICTURE “http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3289113/bin/fpsyg-03-00058-g002.jpg” * MERGEFORMATINET
Duration at 800ms, 1000ms and 1200 ms and ANOVA with motion (static or moving) were each measured repeatedly within subject factors. This was done in reference to the stationary reference to study the effect of the motion of an object on the perceived duration of time. The results of this first experiment revealed significant main events of Duration [F (2, 22) =214.866, p<0.001] and motion [F (1, 11) = 15.939, p=0.002]. The overall product of motion and duration also produced a significant value [F (2, 22) = 6.149, p=0.008]
Post hoc paired sample tests for t revealed that the difference between the two conditions (static and motion) were significant at the time of the duration at 800 ms, but did not reach significant level at 1200 ms. The same ANOVA (motion ×duration) was also performed on the data of the moving control experiment. This showed significant main effects of duration and motion. The values for motion × duration for this data were also found to be significant. When Post hoc tests for t were conducted the result revealed significant differences between the static conditions and motion conditions at the presentation duration of 1200 ms but failed to produce significant values at less than 800 ms. There was marginally significant difference at the 1000ms duration of presentation.
Both the control and main experiments showed a similar trend of a longer perception of time when the object was in motion. The control experiment showed that the time dilation effect was based on change in motion without a play of novelty of the stimuli.
The scientists then conducted a second experiment to investigate time dilation under object motion with eye movement. Findings from this second experiment revealed that that the time dilation associated with the movement of an object depends on the motion of the object that has been perceived in the brain rather than the positional shift of the image that is projected in the retina of the observers.
Another concept that is being applied in present time travel experiment in Albert Einstein’s relation of physiology and physicality. Albert Einstein noted that when a boy sits next to a beautiful girl it feels like a minute but on his own it feels like an eternity. He proposed that this is some form of mental travel and that its physical application would mark real time travel. (Catalin V. Buhusi) Experiments are being designed based on this concept to acquire insight into time travel.
In conclusion, the experiments featured demonstrate that time dilation is dependent on spatial motion rather than retinal motion. They also ascertain the possibility of inducing time dilation on the acceleration of a particle in relation to a constant observation. This is based on Einstein’s theory of special relativity: the movement of an object (approaching the speed of light) analogous to that of another exhibits differences in aging between the two bodies. This aging is manifested in biological, chemical and physical aspects. When motions of the targets were accelerated, the observers saw a difference between the reference object and that of a similar object used for comparison. This suggests that if a discovery is made on how to accelerate the cells of living organisms without inflicting any harm to the individual then it would not be impossible to achieve time travel. This defiance of Newton’s laws of motion would only be achieved if the living cells travel at a speed close to that of light. Presently there is a lack of technology that can achieve the acceleration of living cells to this speed. Physicists and other scientists are working on realizing this. Their research has gained significant ground on the matter through numerous experiments. The experiment featured in this paper ascertains that time dilation, an aspect of time travel, exists in the world as of present. This discovery coupled with other similar ones e.g. mental time travel promise that it is only a matter of time before scientist find a stable method of facilitating time travel for humans. This is likely to be achieved in the near future based on the rapid rates of experiments investigating the fourth dimension. This justifies the hypothesis that time travel will be possible in the future.
Ricky K. C. Au, Katsumi Watanabe. “Time Dilation Induced by Object Motion is Based on Spatiotopic but not Retinotopic Positions.” Frontiers in Psychology, 3. (2012): Web. 30 Nov 2013.
“Einstein’s Theory Passes a Space ‘Laboratory’ Test.” The Christian Science Monitor (pre-1997 Fulltext): 0. Jan 22 1992. ProQuest. Web. 30 Nov. 2013 .
Morris, Richard. “The Perils of Time Travel.” The Futurist 28.5 (1994): 60. ProQuest. Web. 1 Dec. 2013
Catalin V. Buhusi, Warren H. Meck. “Relativity Theory and Time Perception: Single or Multiple Clocks?.” PLoS ONE, 4. 7 (2009): Web. 1 Dec 2013.
“How Time Travel Will Work.” Bibliotecapleyades.net, 2013. Web. 1 Dec 2013. <http://www.bibliotecapleyades.net/ciencia/time_travel/esp_ciencia_timetravel25.htm>.