Tuesday, September 12, 2006

Is the Big Bang in trouble?

Yesterday, Space.com posted this article, claiming that a new scientific study may call the Big Bang into question. Is this true?

The Big Bang is the most successful theory proposed for the creation and evolution of the Universe. The theory was developed after Edwin Hubble observed that almost every galaxy in the Universe is moving away from every other galaxy, now understood as the expansion of the Universe. The theory has made some remarkable predictions that were shown to be true, such as the cosmic microwave background ("echoes" of the Big Bang visible in radio waves) and the ratio of hydrogen to helium in the Universe, to name a couple. Tweaks to the Big Bang (such as the theory of Inflation) made other predictions that have been shown to be true, such as the shape of the Universe and the small variations in the cosmic microwave background. So the Big Bang theory is amazingly successful, and it would take very compelling data to cause most scientists to question it.

The study looked for shadows of clusters of galaxies on the microwave background -- extremely hot gas in the galaxy clusters should distort the wavelengths of the radio waves from the Big Bang. However, the study on Space.com found much weaker shadows from many galaxy clusters than theory would predict. The study's authors state that the most likely explanation is that we don't understand the galaxy clusters as well as we thought, and this seems a quite reasonable explanation. However, one other explanation is that we don't understand the cosmic microwave background as well as we thought, which would throw the Big Bang into question.

Given the mountain of evidence supporting the Big Bang and the likelihood that we don't understand clusters of galaxies, the study's authors (and yours truly) feel that the Big Bang is quite safe. But we must be honest and admit that there is a tiny, tiny chance that the Big Bang theory may be incomplete or incorrect.

But does such a small chance warrant a large article under the "Cosmic Mysteries" section of a media outlet? Probably not. Such stories create tempests in a teacup that mislead members of the public into thinking the Big Bang is more controversial than it actually is. Of course, the media have ever right to pick up on this story, and I certainly won't write Space.com and argue that such stories should not be printed.

More importantly, this is a warning to you, the member of the public. When you read that one scientific study or another challenges a major theory, be skeptical. More often than not, any controversy is overblown, and most of the rest of the time, the research is of questionable quality. And always feel free to ask a professional for the real skinny!

1 comment:

  1. The "Mountain of Evidence" is biased: only the Big Bang is extensively studied, so all "evidence" goes to Big Bang. On the other hand, it is risky for the career to pursue research contradicting Big Bang...

    I think cosmology have gone Byzantine, i.e. the scientific culture of cosmology have lost it's research mechanisms for consensus, elevating the counterparts of Aristotelean physics, Ptolemeic epicycles and Galenos medicine as dogma that cannot be contradicted.

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