Gravity affects the perception of time through a phenomenon called “time dilation”. Essentially, time appears to pass more slowly in strong gravitational fields or at high speeds. This concept is central to Einstein's theories of relativity.

Einstein's theory of General Relativity, published in 1915, shows that time is not a constant and universal measure. Instead, time varies depending on gravity, meaning there isn’t a single, uniform clock ticking throughout the universe. Time moves more slowly near massive objects due to their gravitational influence.

According to this theory, every observer has their own clock, which ticks more slowly when they are in a stronger gravitational field or moving at a higher speed. It’s important to note that surpassing the speed of light is currently considered impossible according to the laws of physics as we understand them. If we could somehow achieve such speeds, the effects of time dilation would become extreme, but we wouldn’t achieve "eternity" in the literal sense, time would simply slow down significantly relative to stationary observers.

For example, consider two identical clocks: one on the surface of the Earth and one on a satellite orbiting far above. The clock on the surface will tick more slowly than the clock in orbit due to the stronger gravitational field on the Earth’s surface.

In addition, when discussing motion, we refer to Einstein's Special Theory of Relativity, published in 1905. This theory addresses how motion affects time, revealing that time also slows down for objects moving at speeds close to the speed of light. This effect becomes more pronounced as the object's speed increases, and the degree of time dilation can be calculated using the Lorentz factor, which depends on the velocity of the moving object relative to the speed of light.

The theory is based on two main ideas: the speed of light is constant for all observers, regardless of their motion, and time and space are relative.

In practical terms, the theory has several important applications. GPS satellites, which orbit the Earth at high speeds, must adjust their clocks for time dilation effects to provide accurate location data. In particle accelerators, time dilation and length contraction are considered to predict the behavior of high-speed particles. Even high-speed electronics need to account for relativistic effects to function correctly. Additionally, Special Relativity helps explain high-speed cosmic phenomena, such as particles emitted by black holes and pulsars, enhancing our understanding of the universe.