Timeline of the Big Bang
Right after the Big Bang
Q: What happened after the Big Bang?
A: Scientists use a machine called a particle accelerator to find out. This machine is underground. It makes tiny particles move very fast.
Scientists discovered new tiny particles in these tunnels.
Subatomic Particles
Q: What are subatomic particles?
A: Subatomic particles are smaller than atoms. Some are inside atoms. Others are found in stars or labs.
Scientists study them in a science called particle physics.
Cosmic Inflation
Around 10-37 seconds after the Big Bang:
Q: What is cosmic inflation?
A: The universe was very hot and dense. It expanded and cooled quickly. This phase is called cosmic inflation. The universe grew very fast in size.
The Early Universe
Q: What was the early universe like?
A: The universe had high energy and temperature. It was the same in all directions. It expanded quickly and became cooler.
Figure A: Development stages of the universe. Time is on the horizontal axis.
Antiparticles
After cosmic inflation:
Q: What are antiparticles?
A: The universe had quark-gluon plasma and other tiny particles. These particles moved very fast. Particle-antiparticle pairs were created and destroyed. An antiparticle is like a normal particle but with opposite properties. For example, it might have the opposite charge.
Annihilation
Around 10-11 seconds after the Big Bang:
Q: What happened during annihilation?
A: The universe cooled down. Quarks and gluons formed baryons, like protons and neutrons. These make up atoms. A small excess of matter over antimatter led to the dominance of matter.
Big Bang Nucleosynthesis
Around 1 second after the Big Bang:
Q: What happened during Big Bang nucleosynthesis?
A: Electrons and positrons destroyed each other. The universe's energy was dominated by photons. Neutrons fused with protons to form deuterium and helium. A few minutes into expansion, the temperature was a billion degrees Kelvin. Neutrons and protons formed deuterium and helium. Most protons stayed as hydrogen nuclei.
Cosmic Microwave Background Radiation
Around 379,000 years after the Big Bang:
Q: What is cosmic microwave background radiation?
A: The universe cooled down. Electrons bonded with atomic nuclei, forming the first atoms, mainly hydrogen. Space became transparent, and radiation moved freely. This radiation is known as the cosmic microwave background radiation. It shows us the early universe.
Conclusion
Q: How did the universe form?
A: The universe didn’t always have subatomic particles. They formed through a complex process over millions of years. These particles eventually formed the universe as we know it today.