|
The Big Bang Theory is currently the dominant scientific explanation for the origin of the universe. It was first proposed in 1927 by a Belgian priest named George Lemaître. We found a collection of sites about the Big Bang theory in a Yahoo! Astrophysics subcategory called Universal Origins by searching on "big bang." This mind-boggling array of resources proved a little too scientific, so we tried to find a simpler place to start. A fascinating physics study module called Violence in the Cosmos provided us with some Big Bang basics: - Ten
to twenty billion years ago, the universe consisted of a compact ball of hydrogen -- protons, neutrons, electrons, and their anti-particles -- plus radiation. There were no differentiated planets, stars, suns, galaxies.
- Five billion years ago, the compact hydrogen soup blasted apart with huge force, matter was hurled in all directions, and the universe doubled in size. This expansion of the universe is still going on.
- The blast caused a major decrease in the density and temperature of the universe after which no new particles could be formed. Then the particle wars began. Particles and anti-particles fought it out in a frenzy of self-destruction. The universe was left with a greatly reduced collection of positively-charged nuclei and negatively-charged electrons in a vast
plasma soup.
- Although plasma (ionized gas) rarely occurs on Earth's electrically neutral surface, 99% of the matter of the Universe still exists in a plasma state.
- The Big Bang produced the light elements hydrogen and helium. Heavier elements are usually produced in the violent processes associated with the death of stars.
Despite later discoveries by astronomer Edwin Hubble and Nobel Prize-winning scientists Arno Penzias and Robert Wilson that appear to support Lemaître's theory, the theory remains controversial and alternative explanations for the origin of the universe abound.
|
