Physical Forces


The Big Bang

We are part of this universe; we are in this universe, but perhaps more important than both of those facts, is that the universe is in us.

~ Neil deGrasse Tyson, astrophysicist

Spiral galaxy known as NGC 1433, 32 million light-years from Earth.
ESA/Hubble & NASA D. Calzetti (UMass) and the LEGUS Team
Cosmology is a science that concerns itself with the origins and continuing evolution of the universe. The most widely accepted explanation for how the universe came into existence is known as the Big Bang Theory. It proposes that 12 to 14 billion years ago, a millimeters-wide universe emerged from formless energy, as a singularity.

A singularity is an area of infinite gravity where immeasurable heat and pressure generate distortions in time and space. Instability resulting from these extremes led to radioactive decay of the core and ultimately, to an immense explosion – a “big bang” – that initiated the universe’s expansion into the limitless body it is today. This notion of an expanding universe was demonstrated experimentally by American astronomer Edwin Hubble in 1929, who noted that galaxies continue to drift apart.