Transcript The Big Bang Theory - Stefanie's ePortfolio

The Big Bang Theory
By Stefanie Pacheco
Astronomy
How old is the Universe?
• Scientists approximate the universe to be
about 15 billion years old.
• We do not see the whole universe, we do not
know how big it is.
Our Horizon
• We can only see as far as light can travel.
• We cannot see galaxies that are more than 15
billion years old because they have not yet
entered our horizon.
How did it all start?
• 0
• The Universe started out very small and very
dense.
Inflation
• 10-32 seconds
• The universe underwent an initial inflation
that lasted a infinitismle fraction of a second.
Which means it expanded much faster than
the speed of light.
Causes of Electrons
• The Universe was very hot, atoms couldn’t
exist.
• Electrons caused very small packets of light
called photons to scatter continuously, light
was linked to the particles, causing the whole
universe to glow.
Quark Soup
• 1 Second
• Universe looked like a plasma “soup” of
protons, electrons, neutrons, neutrinos,
photons, etc.
Big Freeze Out
• 300,000 years
• Things start to cool off as they expand off, as
the universe continued to expand it cooled off.
• 300,000 years passed and it cooled off enough
so atoms could form.
Parting Company
• Photons scattered ionized particles like
protons and electrons
• Photons traveled through space in straight
paths instead of constantly being scattered by
electrons.
Parting Company
• This lead to the formation of the elements,
hydrogen and helium.
• Photons made up a uniform light radiation
that filled the whole universe.
First Galaxies
• 1 Billion Years
• Regions of the universe became very dense.
• Gravity overcame the expansion and formed
galaxies and galaxy clusters.
The Milky Way
• Our own galaxy
• Part of a galaxy of clusters
Modern Universe
• 12-15 Billion Years
• The universe today is observed to contain one
helium atom for every ten or eleven atoms of
hydrogen.
Tour of the Universe