Lecture

The Origin of Space, Time, and Matter

Icon reminds us that between 1 - 10% of the static on our TV sets is due to the Cosmic Microwave Background Radiation.

Horrendous Space Kablooie

From Wikipedia, the free encyclopedia.

The Horrendous Space Kablooie is an alternate term for the big bang. It was coined by Bill Watterson, creator of the comic strip "Calvin and Hobbes."

In one strip, Calvin says to Hobbes, "I've been reading about the beginning of the universe. They call it 'The Big Bang.' Isn't it weird how scientists can imagine all the matter of the universe exploding out of a dot smaller than the head of a pin, but they can't come up with a more evocative name for it than 'the Big Bang'? That's the whole problem with science. You've got a bunch of empiricists trying to describe things of unimaginable wonder."

Hobbes asks, "What would you call the creation of the universe?"

Calvin replies, "The Horrendous Space Kablooie!"

This term enjoyed a brief popularity in the scientific community and was widely used in informal communications (often abbreviated to "the HSK").


Introduction

"Our minds are continuously preoccupied by an endless series of everyday matters--from shoe tying to television watching. Distraction and diversion might even be considered to play a basic role in our culture; perhaps because beneath the flurry of practical and incidental considerations lurk questions for which we have no satisfactory answers-the kind of tantalizingly ominous, even vaguely dangerous questions that break to the surface when one is quietly gazing at a starry sky on a clear, dark, moonless night. They are not small questions: What does it mean to exist in a universe of incomprehensible size? Is the universe perhaps infinite in space and time? If the universe evolves, are we swept towards annihilation or eternity-what is the fate of the universe? Such concerns are in a sense primordial: they have, in some form, lain at the base of the brain for thousands of generations...waiting. Stripped of romance these questions come out like: What is the structure and evolution of the universe? How does it work? How does it fit together? What is the underlying order that explains the 'world'? These are the questions of cosmology-the scheme of the universe as a whole."

From Professor Paul Boynton's "Cosmology: A Cosmic Perspective."

In this lesson we continue our pursuit of cosmology by studying the very start of space and time--at least as we perceive it today.

Learning Objectives

After listening to the lecture, reading the text, and studying these on-line notes, you should be able to:

  1. Summarize how our views of the cosmos have basically changed over the past 4000 years (!).
  2. Relate what particle physics has to do with the origin of the Universe.
  3. Describe what Calvin and Hobbes has to do with the origin of the Universe.
  4. Explain why the "Big Bang" theory is the most widely accepted theory for the formation of the Universe at the present time, giving the two pieces of evidence that imply a hot, dense origin.
  5. List and briefly describe the two theoretical frameworks for the Big Bang theory.
  6. Explain what is meant by a homogeneous universe, an isotropic universe, and a "homogeneous AND isotropic" universe. Give another way of saying that the Universe is homogeneous and isotropic.
  7. Describe in extremely simple terms what is meant by "inflation of the universe."
  8. Outline the first 5 eras of the Universe, placing them in chronological order.
  9. State the significance of the discovery of the cosmic microwave background radiation.
  10. Summarize completely the way the equation--E=mc2--operated during the particle era.
  11. Discuss what is meant by the "decoupling era."
  12. Give a stellar analogy for the era of nucleosynthesis, era of nuclei, and era of atoms.
  13. Explain how the observations of the cosmic abundances of hydrogen, helium, and deuterium support the "Big Bang" theory.
Terms you should know:


cosmology
homogeneous universe
isotropic universe
inflation
cosmic microwave background radiation
decoupling
Planck era
GUT era
electroweak era
particle era
era of nucleosynthesis
era of nuclei
era of atoms
cosmological constant
singularity
symmetry breaking
matter and anti-matter
particles and anti-particles
cosmological redshift

Contents

Ancient Cosmologies

There have been a variety of cosmologies in the past, there are different cosmologies today, and there will be different cosmologies in the future. A short internet search for the definition of cosmology resulted in the following:

"the study of the formation, structure and evolution of the universe as a whole"; "a branch of metaphysics that deals with the nature of the universe as an orderly system (Webster)"; "discourse concerned with the cosmos and with cosmic questions"; "kosmos Greek for universe and logica to speak -- to speak about the universe"; "the physics of the universe as a whole, everything"; "the study of the universe and its creation as an ordered whole."

Naturally, our perception of just what constitutes the "universe" has had to change. Thousands of years ago we did not have the technology to explore the depths of the Universe as we do now. Humans were concerned with surviving: When to plant crops, when would floods come, when is winter just around the corner? There was a time when we had the technology--in the form of a simple telescope--to change our view of the Universe, but the strict religious dogma of the Church prohibited it.

If we take just a small sample of past views of the Universe, we should be able to get a summary of how our views of the cosmos have basically changed.

STONEHENGE: Thought to have been built over a period of time by the Druids in the present southern England. The stones of stonehenge are precisely aligned to the solstices and equinoxes--the path of the Sun during the year. It is also conjectured that it was used to follow the phases of the Moon.
The goddess Nut of ancient Egypt. One notes the stars on her body and her protection of the people and their animals and their culture.
A Hindu concept of the Universe. The Earth is carried by a tortoise resting on the great serpent, the symbol of eternity.
This is supposedly from a 16th-century woodcut, although in the book by Dr. E. C. Krupp, "Beyond the Blue Horizon," it is said to be probably from a 19th century Frenchman.
Ptolemy's universe. The explanation for the universe, which included a complex but accurate-enough-for-the-times prediction of the motion of the planets, survived for about 1500 years. Here the Earth is at the center, with the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn all occupying orbits around it. This configuration was not good enough to explain all of the phenomena, and so additional circles called epicycles were imposed. When these didn't work exactly right additional adjustments were made until the model became accurate enough to predict planetary positions to within a few degrees.
The Copernican Model. When observations could no longer be refuted (and when Copernicus took radical exception to the model having moved away from a perfect circle), the Sun was placed at the center of the solar system and the Universe. Because Copernicus refused to move away from a perfect circle for the orbits, this model was no more accurate in predicting planetary positions than the erroneous one of Ptolemy.
For a wonderful discussion of ancient cosmologies, please read Program 01 from Prof. Paul Boynton's Cosmology: A Cosmic Perspective (better yet, look for his course that uses this text)

To fully understand the origin of the Universe, we would need to have a fairly comprehensive knowledge of particle physics, and there is just no way. But, it is possible to get a simplified introduction. You should read Chapter S4 of your text, especially Sections S4.1 and S4.2, as that will give you enough background for what we cover here. There are a couple of web sites that I found that will also help should you want a slightly more in-depth understanding:

The Cosmic Microwave Background

The Kiss of Death for Believers of a Steady-State Universe


The Discovery


Characteristics of the CMB

The Microwave Anisotropy Probe (MAP) , a complete introduction-to-cosmology web site (and the basis for much of the lecture on cosmology).


Theoretical Foundation

The theoretical foundations were 1) general relativity, where Einstein proposed a new view of gravity; 2) the cosmological principle: When averaged over extremely large regions, the Universe is homogeneous AND isotropic.

A homogeneous universe looks the same to all observers, but not necessarily the same in all directions. In the above example, one could position an "X" anywhere, and the "universe" would look the same. But, if one looked in one direction, let's say "up," it is not the same as it looks if one looks "across." An isotropic universe look the same in all directions. Here, though, one needs to be at the middle of this "universe" to see the same view in all directions. A homogeneous and isotropic universe looks the same to all observers and in all directions.
What is another way of saying that the Universe is homogeneous and isotropic?

The First 3 Minutes of the Universe

The Standard Model
(Big Bang Theory)

First there was a grapefruit-sized singularity......

Then, the appearance of space and time "that occurred simultaneously everywhere."

After 3 minutes:

Inventory of Universe at this Time:

"I cannot deny a feeling of unreality in writing about the first three minutes as if we really know what we are talking about." (Weinberg)

(The following "time line" assumes a universe that is 20 billion years old.)

Time marches on. When the Universe has an age of:

10,000 years: Matter dominates

300,000 years: Universe becomes transparent at a cosmological redsift, z = 1000

    At this point in the evolution of the Universe, the "smoking gun" is created, one that brings about the consensus for standard model by the pressure of empirical data:

  1. Weak radio static which fills the Universe -- the remnant radiation from when matter and radiation set off on individual paths

    which, when combined with the

  2. Recession of distant galaxies

    brings down hard evidence for a "Big Bang" (or, as Calvin and Hobbs have renamed it -- "The Horrendous Space Kablooie")

1-2 billion: Galaxy Formation

3 billion: Galaxy Clustering

4 billion: Milky Way Galaxy collapses

4.1 billion: first stars form (population III???)

5 billion: quasars are born; population II stars form

10 billion: population I stars form

15.2 billion: our parent interstellar cloud forms

15.3 billion: collapse of protosolar nebula

15.4 billion: planets form and terrestrial planets solidify

15.7 billion: intense cratering of planets

16.1 billion: oldest terrestrial rocks form

17 billion: microscopic life appears

19.99999999 billion years: You are born, grow up, and register for Astronomy 101
The rest, as they say, is history.

Take the Quiz

Instant Response Multiple Choice Practice Exam from the publishers of the text, emphasizing the information in your text.

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