The Big Bang

The Big Bang is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now and it is still stretching!
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One ten million trillion trillion trillionth
of a second

In order to explain what happened scientists use measurements of time that are very small.

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BSL Version

The Big Bang

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At first…

• the Universe was unspeakably small and hot – getting larger and cooler ever since.
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Four fundamental forces

Four fundamental forces govern interactions between all objects in the universe.
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This illustration shows above the four fundamental forces of the universe (clockwise from top left):
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• gravity
• electromagnetism
• weak forces
• strong forces
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Science photo Library/Getty Images: Mark Garlick – Science photo, plus: adapted by L. Steenblik Hwang.

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BSL Version

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About one-billionth of one second…

• about one-billionth of one second after the Big Bang
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• the Universe lay in a dense sea of quarks and other particles – tiny pieces of anything; atoms, molecules, etc).
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Dense sea of quarks
A quark is a tiny particle which makes up protons and neutrons.
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BSL Version

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About three minutes…

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• about three minutes after the Big Bang there was a brief period of nucleosynthesis when quarks joined together to form neutrons and protons.
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Atoms
Atoms are the smallest units of an element
that still retain the properties of that element.

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Nucleus
In a nutshell, atoms are the tiny bits that make up everything we see and touch, from the air to the stars. They’re made of protons, neutrons, and electrons.
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• protons and neutrons are in the centre of each atom is a dense core called the nucleus.
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• despite being incredibly tiny, the nucleus contains almost all of an atom’s mass. This is because the nucleus is home to two types of particles: protons and neutrons.
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• protons – these are positively (+) charged particles found within the nucleus. The number of protons in an atom determines what element it is. (For example, an atom with one proton is hydrogen, an atom with two protons is helium, and so on.)
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• neutrons – these are particles that have no charge (negative), hence the name ‘neutron’, which means ‘neutral’. They contribute to the mass of an atom and help to hold the nucleus together by counteracting the positive charge of the protons.
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• in a nutshell, atoms are the tiny bits that make up everything we see and touch, from the air to the stars; they’re made of protons, neutrons, and electrons.
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BSL Version

• explaining about three minutes…

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BSL Version

• explaining about nucleus

Electrons

Electrons are tiny particles that orbit the nucleus, similar to how planets orbit the sun.
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• they carry a negative charge, which balances the positive charge of the protons in the nucleus.
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• electrons are involved in chemical reactions and the formation of chemical bonds. They also determine the electrical and thermal conductivity of materials.
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• The arrangement of electrons in an atom can change, moving to higher energy levels or lower energy levels or even jumping from one atom to another.
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• These changes can result in the absorption or emission of light, leading to the colours we see in fireworks, neon lights, and even the rainbow!

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BSL Version

• explaining about electrons