Monday, September 03, 2007

Dark Energy "explained"

Until 1929 practically everyone thought that the stars in the skies are fixed in space, that the Universe was pretty much constant and unchanging. Then the astronomer Edwin Hubble published the results of 10 year's observation that showed that the Universe is expanding. Working backwards from his observations, it turns out that the Universe began about 12 billion years ago with an almighty explosion called the Big Bang. Stephen Hawking and Roger Penrose showed mathematically that it all started from an almost dimensionless point, and has been expanding ever since.

The big question was, would it keep expanding forever, or would the force of gravity eventually suck it all back into a dimensionless dot again?

Then in 1998 more precise measurements showed that the Universe is expanding at an ever-accelerating rate. This was a big surprise, because no one knew of any force that could cause this acceleration. It was soon called Dark Energy. Since then, theoretical physicists have had a field day speculating about what Dark Energy might be, and where it came from.

Not to be left out of the fun, I have developed my own theories. They start out with some rather unimportant and boring thoughts about the behaviour of ionized gases and free electrons in the Earth's atmospheres, and that of other planets, and the atmospheres of the sun and other stars. Then they move onto more exotic settings, like the accretion disks around neutron stars and black holes. Up to 10% of the matter falling into a black hole is converted into energy through friction, releasing huge amounts of electromagnetic radiation. This would ionise much of the gas in the accretion disk, freeing electrons. The equipartition of energy principle, an outworking of the second law of thermodynamics, dictates that those electrons that remain free will attain the same mean temperature (i.e. kinetic energy) as has the surrounding gas. Since protons weigh 1836 times more than do electrons, the free electrons will gain much higher velocities than the surrounding gas. Many will achieve escape velocity, and leave the environs of the black hole, while the heavier protons will fall into the black hole and in due course into the singularity at its centre.

In the singularity at the centre of the black hole, the curvature of space, density of matter, and dilation of time are infinite. Cause and effect break down, since it would take an infinite amount of time for a cause to have an effect. It is reasonable to hypothesize that the net positive charge that enters the singularity will become sequestered, and its charge will be completely invisible to the surrounding cosmos, leaving a net and growing surplus of negative charge in the form of the free electrons still rattling around outside. These would flee the environs of the black hole where an apparent excess negative charge holds sway, eventually percolating out of the containing galaxy, but their flight would be impeded by the gas, dust, and magnetic fields within the galaxy. This flight would take a long time, especially for larger galaxies. Those galaxies with central black holes would therefore have an apparent net negative charge; the larger the galaxy, the larger the charge.

If the free electron hypothesis is true then it may account for the Dark Energy that is held to be responsible for the accelerating expansion of the cosmos. The growing numbers of free electrons will repel one another, and this repulsive force is much stronger than the force of gravity, pound for pound.

If all big galaxies have big black holes at their centres, helping to give them gravitational cohesion, then many of the earliest massive galaxies must have been largely consumed by their central black holes by now. If the free electron hypothesis is true then these galaxies would have released prodigious numbers of free electrons by now. These would expand like gigantic, invisible bubbles in the fabric of the cosmos, repelling other (negatively charged) galaxies from their vicinity, and perhaps giving rise to the observed "foam-like" structure of the cosmos. Observation shows that the cosmos is mainly composed of vast empty bubbles of space, with gas, dust, and the visible galaxies clumped into skeins and membranes between these voids. The BBC recently reported the discovery of a huge void in the cosmos.

You can find all of these wild conjectures, and several more, in a paper that I put online recently at

I have also started another blog just to talk about this topic. It's kind of esoteric.

My blog got mothballed!

Hello, World. Again.

My blog is back from the near-dead. It was mothballed by a Blogspot bot, trawling for spam links in blogs. There have been a rash of spam links in blogs, sucking gullible viewers to sites that plant Trojans on the PCs – at least those that run vulnerable operating systems. Here's a link (dare I do this?) to a BBC article that talks about the problem:

Anyhow, I'm back. Sorry for the short interruption in service.