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50 years after Big Bang theory, we're still not sure what happened

bobmcdonald-190.jpgBy Bob McDonald, Quirks & Quarks

Half a century after the idea that the universe began with a colossal explosion was first proposed, scientists are still trying to figure out what exactly happened. They're also hoping to build the largest machine in the world to find out.

At a recent meeting in Geneva, Switzerland, Dr. Rolf Heuer, director general of CERN, home of the Large Hadron Collider, proposed building an even larger particle accelerator to probe the mysteries of the early universe. The new device would have a ring of electromagnets 100 km in circumference - more than three times the size of the existing facility.

This may seem like an extravagant request, considering the Large Hadron Collider is already the largest accelerator in the world, has only been running for a few years and is not even at peak power. The facility has already delivered evidence of the long-sought-after Higgs Boson, but scientists believe there is still much to be learned about the Big Bang - and it will take more power to do it.

The idea of the Big Bang stems from Edwin Hubble's landmark discovery that all distant galaxies are moving away from us. The universe is expanding. It doesn't take a rocket scientist to conclude that if the universe is getting larger today, then if you run time backwards, everything must have been squeezed tightly together at one point.

Whenever anything is squeezed, it gets hot; and if all the matter in the universe were pulled together into one small space, the temperatures and pressures would be so extreme that the object would not be able to hold itself together. In 1931, Georges LemaƮtre proposed that whatever that object was, it must have gone "bang" in a really big way, producing the expanding universe we see today.

It's a nice idea, but it wasn't confirmed until two young astronomers, Robert W. Wilson and Arno A. Penzias, working at Bell Labs in New Jersey 50 years ago pointed their horn-shaped radio antenna towards the sky and heard a persistent hiss from all directions. That hiss, coming from beyond the galaxies, is the remnant of the Big Bang explosion. That discovery won the pair the Nobel Prize.

Since then, more sensitive instruments aboard satellites, such as COBE and WMAP, have mapped the background glow in fine detail, showing how early fluctuations in that explosion evolved into stars, galaxies, planets and, eventually, people trying to understand the whole process.

But the Big Bang Theory left some important questions that have remained unanswered for half a century. If the early universe was unimaginably hot and dense at the beginning, it would have been nothing but pure energy, the same smooth energy everywhere. So how did it change from smooth to lumpy? (Planets, stars and humans are the lumps.)   

And when matter - the stuff we're made of - appeared, there should have been just as much anti-matter produced. So where is all that anti-matter? More recently, dark matter has been detected between the galaxies, and it doesn't seem to be like anything we know. So what is it made of?

Thanks, in part, to the Hubble Space Telescope, astronomers have found that the universe is speeding up. Something called dark energy is pushing it outwards with a force that acts against gravity.

Those last two elements, dark matter and dark energy, make up 95 per cent of the universe and we don't really understand what they are. You would think that after 50 years of research, we would be a little less ignorant about the nature of the universe.

That's why the scientists at CERN want a bigger machine. The only way to re-create the conditions of the Big Bang is to smash pieces of atoms together with unbelievable energy. For a few billionths of a second, in a very tiny space, events could reproduce what happened back at the beginning.

When the Large Hadron Collider comes back online at full power, it will beat its own world record for energy production. But it will not be enough. The energies of the Big Bang far exceed anything that can be created on Earth today.

This is science at its most fundamental. Understanding the laws that govern even a small part of the universe has yielded everything from rockets to quantum computers. Who knows where the laws of the "dark universe" will take us, 50 years from now?

We won't know until we take a look.