Final answer:
According to the special theory of relativity, traveling at a significant fraction of the speed of light could result in significant time dilation, allowing you to age very little while many years pass on Earth. This occurs because time slows down for the traveler compared to someone at rest on Earth as they approach the speed of light, but practical and energy limitations make this form of time travel currently beyond our reach.
Step-by-step explanation:
Understanding Time Dilation in Relativity
According to Einstein's theory of relativity, specifically the special theory of relativity, one could travel many years into Earth's future without aging very much through the phenomenon known as time dilation due to high velocity. This effect occurs when you move at a significant fraction of the speed of light (c). As your velocity approaches c, the rate at which time passes for you slows down relative to an observer at rest, such as someone on Earth. This is because, according to relativity, the speed of light is the maximum speed at which information and matter can travel, and as you approach this speed, time effectively 'stretches' for you compared to someone who is not moving at such high velocities.
For example, if an astronaut were to travel at a velocity that constitutes a significant fraction of the speed of light, they would experience time passing slower for them compared to those who remained on Earth. When they return, they would find that many more years have passed on Earth compared to their own experience of time, effectively having 'travelled' into Earth's future. However, practical limitations, such as the need for immensely greater energies to reach such velocities, make this form of time travel currently impossible.
The concept behind this relies on Einstein's postulates stating that the laws of physics are the same in all inertial frames of reference, and that the speed of light in a vacuum is constant and does not depend on the motion of the light source or observer.