BIG BANG THEORY Grade 11

BIG BANG THEORY

-Proponents of the theory were Alexander Friedman and Georges Lamaitre in 1920 

around 13.7 billion years ago, there was nothing and nowhere.

 due to random fluctuation in an empty void, there was a great explosion or expansion

The occurrence of the of the Big Bang resulted into several events that lead to the creation of forces and celestial bodies known today. The description of the events.

 1. Inflationary epoch - the universe expanded from the size of an atomic nucleus to 1035 meters in width.

2.Formation of the -6 (10 s) Universe  the universe continued to expand. It became distinct, possessing gravity, strong nuclear force, weak nuclear force, and electromagnetic force. At first seconds, the universe was made up of fundamental particles and energy: quarks , electrons ,photons, and neutrinos,

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3.Formation of the basic elements ( 3 s) protons and neutrons combined to form hydrogen nuclei. Then, hydrogen nucleic began to combine in pairs to form helium nucleic. This process is called nucleosynthesis.

4. Radiation era (10 000 years) 

most energy in the universe was in the form of radiation. These included different wavelengths of light, X-rays, radio waves, and ultraviolet rays. They formed what was called the cosmic microwave background radiation.

5. Matter domination ( 300 000 years)  matter began to dominate at the end of the radiation era. At this stage, lithium atom began to be formed. Electrons joined with hydrogen and helium nuclei to make small neutral atoms.

6. Birth of stars and galaxies (300 million years)

 the slightly irregular areas of gas cloud gravitationally attracted nearby matter and became denser. The dense gas clouds collapsed and eventually gained enough mass to ignite and produced light. The huge clouds of gas could be the birthplace foe dozens of stars. The groups of star became the galaxies.

FOUR FUNDAMENTALS FORCES

 1.Strong

force - short range (10-13 cm) attractive force which binds the nucleus.

2. Electromagnetic force

 long range force that binds atoms which can either be attractive or repulsive.

3. Weak force

 short range force present in radioactive decay.

4. Gravitational force

 weak, long-range, and attractive force which binds the Solar System.

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Evidences for the Big Bang Theory Galaxies moving away

 Presence of cosmic microwaves background(CMB)  Abundance of light elements