'Reasonable' may not be quite the word to describe either the
scientific Big Bang idea or various religious accounts of origins,
since they all sound like wild stories at first hearing. However, the
other part of your question, about evidence, has a definite answer.
There is an enormous amount of detailed evidence supporting the Big
Bang theory, which makes many rather detailed predictions about what we
should see in the world. Among the things predicted by the general form
of the BB theory (which originated not from imagination but from
solving the equations of General Relativity) are
1. The Hubble recession of the distant galaxies from us.
2. The relative abundances of the light nuclei.
3. The existence and approximate temperature of the cosmic microwave background (CMB) radiation.
More specific modern versions of the BB picture, including cosmic inflation, also correctly predict:
4. A number of extremely detailed features of the statistics of the tiny fluctuations in the CMB from different directions.
5. Detailed features of the fluctuations in polarization of the CMB.
6. Small deviations from the simple Hubble law.
7. The statistics of fluctuations in the distribution of galaxies.
I may have forgotten some of the other evidence, since this is not actually my field.
In addition, back here on Earth there are a variety of other lines
of evidence supporting the picture of the Earth being about 4.5 billion
years old. These include a variety of radiosotope dating methods. There
is overwhelming fossil evidence and internal evidence of DNA sequences
etc. indicating that life has been evolving on Earth for most of that
Quite a number of Biblically-oriented people choose to accept the
overall outline of the story told by the scientific evidence, reading
the Biblical accounts as metaphors and as guides to reading some
meaning into the process. Of course, such interpretations are not
acceptable to all religious groups.
(republished on 07/19/06)