Dark matter matters
DARK matter, discovered 50 years ago, is now part of our pop- culture, as evidenced by the title of a short- lived space opera.
Astronomers who recently discovered an ultra- diffuse galaxy with 99.9 per cent dark matter have now found one with no dark matter at all.
Previously maverick physicists have been trying to modify the gravitational laws of Newton and Einstein to do away with any need for dark matter in the universe.
Stephen Hawking, whose ashes have been interred next to Newton in Westminster Abbey, was a great advocate of dark matter when he was not promoting black holes or making guest appearances on The Simpsons or The Big Bang Theory. The sitcom even had a parody of astrophysicists trying to write a formula for dark matter and the traditional torch joke.
One of the sci- fi episodes had a dark matter nebula, which theoretical physicists claim is not beyond the realms of possibility. It’s use as a fuel source in Futurama, however, is too fanciful to solve any of the world’s problems.
Although dark matter has been detected indirectly through its effect on acceleration of stars and on light waves from distant galaxies, direct detection is more difficult because scientists don’t know what it is. Apparently, in the 1930s Fritz Zwicky’s dunkle Materie should have been called “clear” or “invisible” matter.
Evidently it passes through our body billions of times per second without any ill- effects. Because there is no agreement as to whether it is a particle like WIMPs or neutrinos or a field, experiments to find it have failed.
The Large Hadron Collider, after discovering the Higgs boson particle, has just spent two years discovering nothing. Although dark matter was formed in the first trillionth of a second after the Big Bang and currently occupies 25 per cent of the cosmos, five times more than ordinary matter, it is being diluted by a universe which is expanding exponentially.
Perhaps we should just be glad, as one science author claims, that dark matter was responsible for the demise of the dinosaurs and hence the evolution of mammals. WILLIAM ROSS,
Cranbrook.