Astronomy |
The Big Bang theory |
Galaxies |
Stars |
Planets and planitissimals |
The Solar System |
|
Astronomy |
The Big Bang theory |
Galaxies |
Stars |
Planets and planitissimals |
The Solar System |
image from Cosmic Mystery Tour page
Copyright, © 1995: Board of Trustees, University of Illinois
Assuming the validity of the Big Bang theory (and it is only a theory, albeit one that has a lot of evidence going for it), the universe can be defined in terms of time, space, and temperature. At the actual start of the Big Bang, there is no size (only a point) and temperature is infinite. This is another way of saying what we have here is a Singularity, a point at which the known laws of the universe no longer apply. As the universe expanded it went through various phases and stages, referred to as "eras" although most only lasted for a trillionth of a second or so. These are summarised in the following timescale (click for more detail)
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in degrees Kelvin |
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| 0 seconds | infinite | 0 | The Big Bang begins and hence space and time come into existence. |
| Plank Era - our present-day formulation of physics fails in principle to be able to explain what was going on. The quantum wavelength of the universe was larger than the size of the universe itself. The universe has complete symmetry: all four forces we know today were unified. | |||
| 1x10-43 seconds | 1032 | 10-35cm
(Planck length) |
At the Planck time, symmetry breaks. Gravity becomes a distinct force. We have entered the GUT era. Here we have the Quantum limit of classical general relativity |
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| 1x10-38 seconds | 1029 | Limit of perturbative interaction - thermalization of universe | |
| 1x10-35 seconds | 1028 | Grand unification and spontaneous symmetry breaking
The universe enters a state called a "false vacuum", |
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| 1x10-34 seconds | 1027 | Approximate start of inflation. | |
| 1x10-32 seconds | 1027 | Approximate start of reheating and end of inflation | |
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| 1x10-32 seconds | Electroweak era begins | ||
| 1x10-11 seconds | 3x1015 | 2 light-minutes | End of Electroweak era. The electro-weak force breaks down into two distinct components, the weak nuclear force and the electro-magnetic force. |
| 2x10-7 seconds | 2x1013 | about size of the Solar System | Tauon anti-tauon annihilation |
| 1x1013 | The energy density is no longer sufficient to create quarks, so quarks freeze out of the universe. | ||
| 1x 10-6 seconds | 12x1012 | 1.4 light-days | The energy density is no longer sufficient to create protons. The annihilation of baryons (protons and neutrons) destroys all the antibaryons and all but one per billion of the baryons |
| 7x10-5 seconds | 3x1012 | Muon anti-muon annihilation | |
| 1/10 second | 3x1010 | Neutral current weak interactions become too slow and neutrinos decouple | |
| 1 second | 1x1010 | 4 light-years | Charged current weak interactions become too slow and neutron to proton ratio freezes out |
| 10 seconds | 5x109 | Electron positron annihilation | |
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| 100 seconds | 1x109 | Typical photon energies drop below the deuteron binding energy and nucleosynthesis (helium making) begins | |
| 200 seconds | 8.4x108 K | 55 light-years | |
| 1000 seconds | 4x108 =
400,000,000o K |
Particle energies drop below coulomb barrier energies and nucleosynthesis ends (end of helium making) | |
| 3,000 years | 60,000o K | Matter density becomes equal to radiation density | |
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| 300,000 | 3500o K | transparent universe - atoms form - matter predominant | |
| 500,000 years | 3000o K | 1,500,000 LY | Photon decoupling |
| 1 billion years | 20 o K | Formation of galaxies | |
| ~2 billion years | most chemical elements made | ||
| 7 billion years | Formation of the solar system | ||
| 8.5 billion years | Emergence of life on Earth | ||
| 12 billion years | 2.726o K | now | |
HISTORY
EVENTS IN AN INFLATIONARY BIG BANG COSMOLOGY - by Niel Brandt
The Evolution of the
Early Universe--The Brief Version - Professor
John Broderick
Introduction
to Astronomy - The Universal Timeline - Prof. Frederick M. Walter
Everything we thought we knew about the universe is wrong! In the past year astronomical observations of type Ia supernovas have led to the conclusion that the universe is not only eexpanding and will expand forever, but also that it is accelerating as it expands, with a long- range "antigravity" repulsive force driving its expansion. The current explanation for this observation is that about 3/4 of the energy from the Big Bang is not in the form of matter but in the vacuum itself and that this vacuum energy is creating a negative pressure that accelerates the expansion of the universe. So the book-keeping seems to be that about 70% of the energy in the universe is in the vacuum, about 5% is in the form of normal matter (protons, planets, stars,galaxies, etc.), and the remaining 25% is "dark matter", mysterious invisible particles that inhabit the haloes of galaxies.
This new understanding raises far more questions then it answers. Why and how does the vacuum store energy? What is the dark matter? Why is the energy from the Big Bang distributed in this particular way? Is the energy in the vacuum constant with time, or is it changing? Could the vacuum suddenly decide to dump its energy and restart the Big Bang? And so on. The universe is a stranger place than we had imagined."
http://www.npl.washington.edu/AV/altvw96.html
http://www.nytimes.com/library/national/science/113099sci-space-galaxies.html
from Graham Kendall's G.L.K file collection
|
Astronomy |
The Big Bang theory |
Galaxies |
Stars |
Planets and planitissimals |
The Solar System |
Introduction
to Cosmology - Cosmology is the study of the origin
and evolution of the Universe. This web site introduces basic concepts
in modern cosmology and describes the MAP (Microwave Anistropy Probe) mission
at a general level.
Cosmos in a Computer good introduction to modern cosmology, includes movie files
Origins
- Timeline of the Universe - This tutorial follows the 15-billion-year-long
history of the Universe. The image above illustrates the major chain of events that eventually led
to life on Earth. The sequence starts with the Big Bang and proceeds to
the Chemistry of Life
History
of the Universe Timeline - From the Big Bang to the End of the
Universe - The Mysteries of Deep Space Timeline - features clickable image
map
A
Spacetime Map of the Universe - part of
John Gowan's
General Systems HomePage
no
title - by Richard McCray - good summary of various cosmological
topics
Universe
put on the map - from BBC News Online: Sci/Tech
NASA/Marshall Science News Subscription Service -
be notified about the latest discoveries
- it's free and it's cool :-)
Space, Time, and Relativity - David Pratt - argues against Einsteinian Relativity and the Big Bang paradigm from a Theosophical perspective
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