"Time and Space are not Absolute"
In 1905, a 26-year-old patent clerk named Albert Einstein shattered our understanding of reality. Before him, Isaac Newton's view prevailed: time and space were absolute and unchanging stages. Einstein's Special Theory of Relativity proved that time and space are fluid and linked, forming a four-dimensional fabric called "Spacetime." He showed that time slows down for objects moving fast relative to an observer. The only constant in the universe is the speed of light.
This elegant equation reveals that mass (m) and energy (E) are interchangeable. Because the speed of light (c) is squared, a tiny amount of mass can be converted into a tremendous amount of energy. This principle powers the sun through nuclear fusion and is the basis of nuclear energy on Earth.
In 1915, Einstein expanded his theory to include gravity. He proposed that gravity is not a mysterious force pulling objects, but the curvature of spacetime caused by mass. Imagine a bowling ball on a trampoline; it curves the fabric, causing marbles to roll toward it. Similarly, the Earth orbits the Sun because it is following the curves the Sun creates in spacetime.
Relativity predicts that time passes slower in stronger gravitational fields and at higher speeds. This isn't just sci-fi; it's essential for daily life. The clocks on GPS satellites tick faster than those on Earth due to weaker gravity. Without correcting for this relativistic difference (about 38 microseconds per day), your GPS navigation would drift by kilometers every day.
In 2015, the LIGO observatory detected Gravitational Waves—ripples in the fabric of spacetime caused by the collision of two black holes 1.3 billion light-years away. This confirmed Einstein's final major prediction, opening a new era of "listening" to the universe.