Saturday 14 April, 2001
To Infinity And Beyond
Will cosmologists ever fully understand the universe?
Living Universe explains the latest in astronomical research and unravels some of the mysteries of the galaxy. Here series producer, Martin Redfern, explores the work of scientists and cosmologists who visualise the unimaginable.
Star Gazing
Astronomers seem to have it all their own way! If they lived on Venus or another cloudy planet they would never see the stars. If space was a little more dusty they would never see distant galaxies.
As it is, they can use their telescopes like time machines, looking out into the universe and back through the time it has taken for light to reach them, to see young galaxies as they were 12 billion years ago. With sensitive microwave radio antennas they can see even further back, to the dull remnant of the fireball of the “Big Bang” of creation itself.
Inflation Theory
Cosmologists are even better off. Their speculations and calculations about the early universe often take them far beyond the scope of even the best observations, where no one can prove them wrong.
The best cosmologists make predictions, which can be tested by observation. And the latest observations of the microwave background fit perfectly with the idea that the universe began in a hot “Big Bang” and expanded so rapidly by a process known as “inflation” that it gave us a universe far larger than we can ever observe.
If inflation theory is correct then, what are seen as ripples in the microwave background radiation, have expanded in the present universe to form vast super-clusters of galaxies hundreds of millions of light years across.
They must have begun life as sub-atomic quantum fluctuations: random events on a scale smaller than the size of a single atom and embedded in a universe that was not much bigger.
| 'Today, the universe is still expanding from the “Big Bang.”' |
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The expansion is not as rapid as it must have been in the brief instant of inflation, though it does seem to be accelerating again.
The Big Bang And The Pea
The idea of the “Big Bang” came originally from drawing the lines of that expansion back to a time when the entire universe must have been microscopic. Under such conditions, it seems that the laws of physics that we know, break down and for a long time it was pure speculation as to what went on.
But now, theorists such as Neil Turok, who works with Stephen Hawking in Cambridge, have developed a way of describing that very early universe mathematically. In simple terms Turok model fits the idea of a living universe very well, for it is like a seed, which he calls an “instanton.”
The early universe "or seed" is the size and shape of a pea - indeed, a wrinkly pea, as it carries ripples on its surface that are to be magnified by inflation, leaving their mark in the microwave background and becoming clusters of galaxies.
Everything we can now observe was once contained within that seed and it carried within it, at least embedded in the mathematics, something like the genetic potential of the universe that was to grow from it.
Maths Make Sense
Whether Turoks seed theory is correct or not, there is one remarkable thing about cosmology and that is that it seems to work. The maths makes sense, at least to the minds of people such as Neil Turok and Stephen Hawking. And that in itself is amazing.
Why should it be that we can understand the universe? It's hard to see any evolutionary advantage in having that ability, so perhaps it says something fundamental about our relationship with the universe. Perhaps, in some strange way, we are meant to understand it.
|  |  | | | Understanding The Universe |  |
| | All civilisations have had their own accounts of how the world began. Many religions state that God created the universe.
In the Old Testament of the Bible it took six days. In the Navajo cosmology this world is the fourth world – our being in the world is seen as the final stage of an ascending series.
In the Hindu view, this world is supported by eight elephants and eight snakes.
Now Western science has its version of events: the universe started with a "Big Bang". A massive fireball – and everything that is in the cosmos now, was created then.
All the matter – all the galaxies and all the stars and dust within them – came from that one event. |
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