The Big Bang happened around 13.8 billion years ago.
Scientists think it started from a very tiny spot that had endless density and heat. This event kicked off the expansion of the universe. Here’s what happened next:
Formation of Basic Forces: Right after the Big Bang, three main forces appeared. These are the electromagnetic force, the weak nuclear force, and the strong nuclear force.
Cosmic Microwave Background Radiation (CMB): About 380,000 years after the Big Bang, light particles, called photons, began to separate from matter. This created the CMB, which has a very chilly temperature of around 2.7 Kelvin.
Making Elements: In the first few minutes after the Big Bang, the very first elements were formed. These were mostly hydrogen (about 75%) and helium (about 25%). This process is known as Big Bang nucleosynthesis.
Today, the universe is still growing bigger, and it’s doing it faster and faster. This is shown by Hubble's Law. Hubble's Law tells us that how fast something moves away from us depends on how far away it is. This can be explained with a simple formula: speed (v) equals the Hubble constant (around 70 kilometers per second for every megaparsec) times the distance (d).
So, the more distant something is, the faster it seems to be moving away!
The Big Bang happened around 13.8 billion years ago.
Scientists think it started from a very tiny spot that had endless density and heat. This event kicked off the expansion of the universe. Here’s what happened next:
Formation of Basic Forces: Right after the Big Bang, three main forces appeared. These are the electromagnetic force, the weak nuclear force, and the strong nuclear force.
Cosmic Microwave Background Radiation (CMB): About 380,000 years after the Big Bang, light particles, called photons, began to separate from matter. This created the CMB, which has a very chilly temperature of around 2.7 Kelvin.
Making Elements: In the first few minutes after the Big Bang, the very first elements were formed. These were mostly hydrogen (about 75%) and helium (about 25%). This process is known as Big Bang nucleosynthesis.
Today, the universe is still growing bigger, and it’s doing it faster and faster. This is shown by Hubble's Law. Hubble's Law tells us that how fast something moves away from us depends on how far away it is. This can be explained with a simple formula: speed (v) equals the Hubble constant (around 70 kilometers per second for every megaparsec) times the distance (d).
So, the more distant something is, the faster it seems to be moving away!