A Bang or a Whimper?

By Ebert, Ronald | Skeptic (Altadena, CA), Summer 2000 | Go to article overview
Save to active project

A Bang or a Whimper?

Ebert, Ronald, Skeptic (Altadena, CA)


WHERE DID IT ALL COMB FROM? Religions have been invented in part to answer this question, but today we use science to discover the truth about the world. In recent times, science has discovered a great deal about the origin of the universe but many questions remain unanswered. This article will discuss some of the rapidly changing discoveries in this field which often change the way we view our theories.


In the mid-20th century there were several competing theories for the origin and evolution of the universe. The Big Bang theory was based on three key observations. The most basic was that the universe was expanding. Spectral light of distant galaxies showed a shift of key features toward the longer, red end of the spectrum when compared to the spectral light of elements generated in a laboratory. The consensus was and still is that the movement of distant galaxies away from the earth causes this redshift. This is similar to the change in pitch heard as a whistle-blowing train passes--the Doppler shift. What's more, for galaxies that were apparently twice as far away as measured by their brightness, the redshift was twice as great. The discovery of this remarkable linear relationship, now known as Hubble's law, was evidence of an expanding universe. In such a universe, every galaxy, or group of gravitationally bound galaxies, moves away from every other. If we project such a universe back in time, it was sign ificantly hotter and denser than it is now.

This realization led to two other predictions. Early in its history the universe must have been hot enough for a burst of nuclear reactions to occur. The proportion of light elements and their isotopes that would have been formed in this nucleosynthesis era were calculated and later verified by observations. It was also realized that the early universe would have been so hot that matter would have been ionized--free electrons, protons, and bare atomic nuclei would have been present. Photons, particles of light, would not have been able to travel far before colliding into other particles. (in fact the photons and free charged particles--ions-formed a sort of fluid.)

The universe at this time was opaque, similar to the surface of the sun today. But as the universe expanded over time, it cooled. It was calculated that about 300,000 years after the beginning, the temperature dropped low enough for the ions to combine into atoms. This caused a drastic drop in charged particles, allowing photons to travel reasonably long distances before they collided with ions. The universe became transparent. The light that was released expanded along with the continued expansion of the universe, and cooled. Today this radiation should be present in the microwave region of the radio spectrum. We have detected this radiation and we now call it the cosmic microwave background radiation (CMB).

The redshifts of galaxies, the proportions of light elements, and the CMB are the three key pieces of evidence that validate the Big Bang. But the Big Bang has had its detractors. The two main competitors were the Steady State theory (its proponents later modified it and called it the quasi-Steady State theory) and plasma cosmology. In its original form, the Steady State model proposed that the universe was not only isotropic (the same in all directions) and homogenous in space, but unchanging as well. A Steady State universe has no beginning or end. It is infinitely old, and as it expands a continuous creation of matter is required to maintain the average density of the universe that we see today. Its proponents claimed that nucleosynthesis took place in stars rather than in the early hot, dense universe. But with this mechanism, the calculated proportion of helium is different What's more, the Steady State universe does not predict a background radiation and distant parts should look the same as nearby par ts.

The rest of this article is only available to active members of Questia

Sign up now for a free, 1-day trial and receive full access to:

  • Questia's entire collection
  • Automatic bibliography creation
  • More helpful research tools like notes, citations, and highlights
  • Ad-free environment

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
Loading One moment ...
Project items
Cite this article

Cited article

Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited article

A Bang or a Whimper?


Text size Smaller Larger
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

While we understand printed pages are helpful to our users, this limitation is necessary to help protect our publishers' copyrighted material and prevent its unlawful distribution. We are sorry for any inconvenience.
Full screen

matching results for page

Cited passage

Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.

Are you sure you want to delete this highlight?