Vacuum Decay

It has been thought that an asteroid or comet hitting the earth would be the worst possible thing to happen. But theoretical physicists have been studying a different and new phenomenon that if it were to happen would destroy not just the earth but the universe itself in an instant! It has been termed vacuum decay. This is a cosmic catastrophe no one could do anything about, the vacuum state in which all things live would disintegrate. It would destroy the universe as we know it. Harvard's theoretical physicist, Sidney Coleman, was the first to uncover the full implications of such a catastrophe, he states, "...I was just delighted to see such a beautiful and novel result coming out of equations that other people had looked at before and not seen that it was there." The equations that Coleman had studied showed him that the vacuumous states as we know them, did not have the same structure as first believed. Coleman says, "Let's gear ourselves and imagine that the familiar vacuum we've been living for 13 billion years or so, is in fact not the most stable vacuum. This is now known as the false vacuum. There's another vacuum even more stable, that's the true vacuum - more nothinger than nothing." This means that if in fact there is a more stable vacuum than 'ours' than our universe could collapse into it!

But, what could make it happen?

The present theory is that it requires a great amount of energy in a very very small concentrated place. Another theoretical physicist, from the college of William and Mary in Virginia, Mark Sheriff, explains, "Cosmic rays are going through space all the time. The highest energy cosmic rays that we know about, you'll have hitting the earth roughly once a century and occasionally, very occasionally one of these cosmic rays, going in one direction, will hit another one head on going in the other direction, that is the sort of energy you would need to touch this thing off and now because it hasn't happened yet, you never know, another cosmic ray might come along with slightly more energy and that might be enough." Sheriff says if this were to happen it would first create a tiny bubble of true vacuum, which is surrounded by the rest of the universe (still in its false vacuum). Sheriff says, "Inside the bubble the laws of physics will be different than outside the bubble and the bubble would expand at roughly the speed of light ( 3x10⁸ms^-1) converting everything it encounters to the new laws of physics." By saying 'new laws of physics' Sheriff means there would be no electrons, protons, atoms, people or even planet! Everything would literally pop out of existence, and vacuum decay doesn't just stop either. Sidney Coleman tells of the consequences, "This would be the ultimate ecological catastrophe, not only would life as we know it be impossible, chemistry as we know it would be impossible; it would be an utterly different universe. It would come without warning and be so swift that there would be no reason, actually no opportunity to amend. No time for phone calls, no time for fear, no time to acknowledge anything is wrong. Were it to happen, you wouldn't know it - you just stop!"

Some people that have learned of the prospect of vacuum decay have taken to protesting outside high-energy physics labs. For example the Thermic National Accelerator Laboratory in Chicago, here scientists use huge accelerators to collide things with atomic nuclei into one another. The people are protesting as they fear this is just the sort of energy required to trigger a vacuum decay. Coleman expresses that this is an unlikely event, "High energy cosmic rays are hitting the earth atmosphere all the time, they are much more energetic by factors of billions or billions and billions and billions, much more energetic than anything we could ever make in any accelerator in the foreseeable future and they haven't initiated vacuum decay - we're still here."

Because vacuum decay is such an unlikely event there are few scientists that study this aspect of it. They are preferring to look at a similar but in some ways an opposite aspect to the vacuum decay. It has been suggested that earlier situation of vacuum decay may been the cause of the beginning of the universe with the cosmological scenario known as the inflationary universe. A physicist at the Massachusetts institute of technology, Alan ? (unsure of last name) states, "The inflationary universe theory cossets that in the very early universe the space was filled with a kind of false vacuum that should in fact have the exact properties you would want to explain how the big bang happened. What it was that drove the big bang. What it was that sent the universe into expansion. At the same time this rapid expansion of the false vacuum can actually create all of the matter that we see in the universe. So it turns out to be a very simple, economical explanation of how the visible universe that we see has originated."