Mystery of the universe confounds our understanding

UNDER THE MICROSCOPE:THE FUNCTION of science is to explain the natural world. However, many natural phenomena remain unexplained by science and some of these are very major matters indeed. In this article I will briefly describe five phenomena that currently challenge science.

Readers who are interested in reading further can consult an entertaining article by Michael Brooks in New ScientistMarch 19th, 2005, entitled "13 Things That Do Not Make Sense".

1. Dark Matter:In the 1970s, the astronomer Vera Rubin noted an anomaly in the way that galaxies rotate around their centres. The galaxies rotate under the force of gravity, but astronomers cannot detect enough matter in the galaxies to produce the observed rate of spin.

Therefore, there must be additional hidden or “dark matter” to account for the spin. But, nobody can yet explain the nature of this dark matter. And, the astonishing and embarrassing fact is that there is five times as much dark matter in the universe as the ordinary matter with which we are familiar.

2. Dark Energy:Since 1998 astronomers have added another phenomenon they cannot explain – dark energy. The universe is expanding, but until 1998 it was thought that the rate of expansion was gradually slowing down. Wrong! The rate of expansion is accelerating and nobody knows why.

A mysterious “dark energy” seems to be pushing the galaxies apart. Overall, the universe is made up of 74 per cent dark energy, 22 per cent dark matter and only 4 per cent ordinary matter.

3. The Horizon Problem:The universe has a diameter of 28 billion light years, having been expanding for 14 billion years from its point origin in the Big Bang. Nevertheless, the universe is incredibly homogenous, with its background microwave radiation at the same temperature everywhere. This implies that even widely separated regions must have been in communication at one time to reach thermal equilibrium, but how this happened is mysterious.

The speed of light sets a limit on how far apart two points can be and still communicate. If you roll back the expanding universe until two opposed points on its perimeter are 299,792km apart (the distance light travels in one second), you would have to roll back time to less than one second after the Big Bang. But light needs an entire second to communicate between these two points, so the universe cannot equilibrate. No matter how much you roll back time, light never has enough time to span the entire universe. This is called “the horizon problem”.

The current proposal to explain the horizon problem is inflation. This says that, shortly after the Big Bang, the universe inflated exponentially, ballooning up by a factor of 1050 in a time of 10–33 seconds (faster than the speed of light). As you roll back time, when you reach the inflationary period you get an exponential contractionwhich overcomes the barrier set up by the speed of light. It can be calculated that the universe now has plenty of time to reach equilibrium.

But the problem is that nobody knows for sure what made inflation happen – if it did happen.

4. Cold Fusion:In 1989, Martin Fleischman and Stanley Pons announced that they had produced cold fusion in the laboratory. Fusion is a nuclear process whereby atoms that are extremely close fuse together releasing massive amounts of energy. Fusion of hydrogen atoms in our sun at a temperature of 20 million degrees is the basis for the massive energy generated by that star. Pons and Fleischman claimed that they had produced fusion at room temperature by inducing deuterium atoms (a heavy form of hydrogen) to fuse together in a lattice of palladium atoms by placing a voltage across palladium electrodes immersed in heavy water (deuterium oxide). Their experiment proved impossible to reproduce.

However, since 1989 many experiments have been run to investigate cold fusion and several researchers report promising results despite the fact that accepted scientific theory pronounces cold fusion to be theoretically impossible.

If controlled cold fusion could be realised the world’s energy problems would be solved. This hope continues to fuel the search for this Holy Grail.

5. The Placebo Effect:The placebo effect is well known in medicine. It refers to a positive therapeutic result when a patient is treated with a placebo, a therapeutically inactive substance, believing the treatment to be a tried and tested therapeutic agent. An example is the substitution of pain-controlling morphine with saline without the patient's knowledge. The saline will take the pain away. To add to the mystery it was recently shown that if you go on to substitute the simple saline with saline containing naloxone, a drug that blocks morphine, the pain relieving power of the saline disappears.

Much work remains to be done to elucidate how the mind affects the biochemistry of the body.

William Reville is associate professor of biochemistry and science awareness officer at University College Cork – http://understandingscience.ucc.ie