Before Albert Einstein, time was considered absolute and universal. Isaac Newton described it as a constant flow that ticks the same for everyone, everywhere in the universe. This idea worked for everyday experiences but could not explain what happens at very high speeds or near massive objects.

Einstein’s theory of relativity completely changed this view. He showed that time is relative, meaning it can move at different rates depending on speed and gravity. For example, an astronaut traveling close to the speed of light experiences time more slowly than someone on Earth. Similarly, clocks placed near a massive object, like a star or black hole, run slower than those farther away.

This discovery had far-reaching implications. It helped scientists understand how the universe works, including the motion of planets, the behavior of light, and even the functioning of GPS satellites, which must account for time differences caused by gravity and speed.

In short, Einstein showed that time is not fixed but flexible. His ideas transformed our understanding of reality, revealing that the flow of time depends on where we are and how fast we move. Time, it turns out, is as dynamic as the universe itself.