Formation of the universe  (Page 4/2)

Natural sciences

Grade 9

The earth, galaxies and space programmes

Module 12

The formation of the universe

At the start of the universe matter did not exist.

According to scientists there was originally only a little ball smaller than an atom of this explosion that became as large as a soccer ball when it started cooling down from infinitely hot to ten billion °C. We don’t know what was in the universe before that.

The explanation that the exceedingly hot spaces and a mixture of particles and forces exploded and started expanding, and are still expanding! The theory is that the galaxies are continuing to move apart. Scientists can still detect the microwaves of the afterglow of the explosion.

This is known as the BIG BANG theory. Only one of the four forces in the universe was in operation, namely the super force - it lasted for only a trillionth of a trillionth of a second!

Cosmologists (scientists that study the universe (cosmos)) have a difficult task, as they have nothing against which to test or compare their ideas. That’s why the “Big Bang” theory came into being. It is a model that they created to explain all phenomena and aspects of this explosion. According to scientists the universe is still expanding.

A scientist by the name of Edward Hubble recorded this movement of galaxies for the first time in the 1920s. He determined that the speed of a galaxy is directly proportional to its distance from us. This is known as Hubble’s Law.

Activity: MAKE A MODEL

• Take an uninflated balloon and paste stars all over its surface. Each star represents a galaxy. Paste a round sticker to represent the Milky Way.
• Now inflate the balloon – note that the galaxies and the Milky Way move further and further apart.

A series of processes in which extreme heat and pressure played a role, led to the formation of matter and elements.

• Hydrogen was formed in the first moments of the formation of the universe after a large number of quarks (Matter: Gr. 8) had been compressed.
• The universe with all its stars and clouds of matter is comprised almost solely of helium and hydrogen, the smallest and lightest of all elements (as you learnt in Gr. 8).
• These elements were formed when the quarks blended with the “matter mixture”, resulting in very high pressure and high temperatures.
• Quarks are so small that 10 billion billion of them next to one another would only stretch one metre.
• Larger atoms such as beryllium were formed when large numbers of helium atoms were joined together in nuclear reactions within stars.
• Iron – an important element in the earth’s crust – was formed deep inside stars when very high temperatures and pressure compressed carbon atoms.All matter in the universe is held together by FOUR FORCES:

• Gravity
• Electromagnetic forces
• Strong nuclear forces
• Weak nuclear forces

Antimatter also exists – it is like a mirror image of matter and should the two groups come together, they would cancel each other out!!!!! Fortunately there is very little antimatter in space.

When Time Began

• In the beginning, when there was no universe yet, there was also no time. The theory is that it all started as follows: