Getting Geeky: Astrophysics and Reality


The radioactive corpse of Cassiopeia A

The radioactive corpse of Cassiopeia A

Long-time readers know that WC can get kind of geeky from time to time. You have been warned.

Science “knows” the universe was born out of a cosmic explosion 13.8 billion years ago. The universe rapidly inflated and then cooled. It’s still expanding but at an increasing rate and is mostly made up of unknown dark matter and dark energy … right?

That’s the theory, anyway, the conceptual framework.

WC has written before that the Big Bang conceptual framework faces some real challenges. Entire galaxies spin faster than their observed mass would predict. Some force seems to hold them together when they should be disintegrating under the laws of physics. So astrophysicists supply more gravity by inventing – not observing, inventing – “dark matter,” invisible stuff that provides enough mass to provide enough gravity to hold those spinning galaxies together. To make it work, some 25% of the universe’s energy-mass has to be undetected dark matter. See how the conceptual framework is saved by sticking on something that has not ever been observed? Awkward!

More recently, in 1998, evidence from distant supernovae implied that out towards the edge of the universe the rate of expansion of the universe seems to be accelerating. Everything we know about physics says that would be impossible without some unknown force causing the rate of expansion to increase. Astrophysicists could detect any force, so they hypothesized – invented – “dark energy.” An unknown, so far undetectable, force which constitutes something like 70% of the universe’s energy-mass. Once again, the Big Bang theory is saved by slapping onto its structure and invisible something. Even more awkward!

WC thinks of astrophysics, especially the observations of other galaxies, as being roughly analogous to an alien doing anthropology from the moon, using only a primitive telescope. You can’t touch anything, your views are often completely blocked, what you are looking for is damned near undetectable and you understand precious little about what you can see. Astrophysicists are trying to observe stuff hundreds of millions of light years away, distances the human mind can’t really being to grasp, and make sense out of it.

The Big Bang model is based on a handful of known, observed facts: Newton’s laws, Einstein’s general relativity, observed expansion of the universe via the red shift and the cosmic background radiation, the “temperature” of the universe as it has cooled down from the Big Bang, 13.8 millions years ago. It’s not like science has observed the Big Bang, after all. It’s an inference from mighty little data. WC isn’t an astrophysicist and is hardly qualified to say the theory is wrong. But there are respected astrophysicists who are saying just that.

The late Thomas Kuhn wrote The Structure of Scientific Revolutions back in 1962. It’s worth reading today. Kuhn suggested that when a paradigm, an accepted group of theories, no longer fit the data, or had to be patched and patched again to accommodate observations, we were at the cusp of the scientific revolution, a comparatively sudden and critical change of paradigms. Astronomy at the Copernican Revolutions; geology at plate tectonics. Read Structure to see his many examples.

For WC, astrophysics seems ripe for a paradigm shift, a change or recasting of theories. WC isn’t holding his breath; the Copernican Revolution took centuries. But the Big Bang edifice, the theory of the origin and history of the universe, seems ready for a major change.

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2 thoughts on “Getting Geeky: Astrophysics and Reality

  1. Nice post and enlightening for me given I only follow astrophysics from the fringes. It is always good to ask yourself from time to time…perhaps everything I know is wrong.

  2. Thanks, brings me back – I once wrote a term paper (in high school, a million years ago) about Georges Lemaitre, who was stil alive. I was curious about the “cosmic egg”… No punch line except to say I do claim credit for introducing the Big Bang to my classmates and family.😀

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