"The Beginning of Everything, 13.8 Billion Years Ago"
Where do we come from? The Big Bang Theory is modern science's most robust answer to this primal question. Approximately 13.8 billion years ago, the entire observable universe was compressed into a single point of infinite density and heat called a "singularity." Contrary to popular belief, the Big Bang was not an explosion in space, but an explosion of space itself. Just as dots on a balloon move apart when it's inflated, the fabric of spacetime itself expanded, giving birth to the cosmos.
The Big Bang is not just a hypothesis; it is supported by pillars of
observational evidence.
1. Hubble's Law (Expansion): In 1929, Edwin Hubble
discovered that galaxies are moving away from us. The farther they are, the faster they recede.
Rewinding this tape leads to a single starting point.
2. Cosmic Microwave Background
(CMB): Discovered accidentally in 1965, this faint "static" is the afterglow of the Big
Bang—the oldest light in the universe, released when it first cooled enough to become transparent
(380,000 years after creation).
3. Primordial Elements: The ratio of Hydrogen
(75%) to Helium (25%) in the universe matches exactly what is predicted to form in the intense heat of
the early Big Bang.
Instead of slowing down due to gravity, the universe's expansion is accelerating. A mysterious force called Dark Energy is pushing galaxies apart. In the distant future, other galaxies may move away faster than light, leaving us alone in a dark, empty sky.
The early universe contained only Hydrogen and Helium. Every other element in your body—Carbon, Oxygen, Iron—was forged in the nuclear furnaces of stars and scattered by supernova explosions. As Carl Sagan famously said, "We are made of starstuff."