What could anyone possibly mean when they say “Theory of Everything”?
In day to day life, the word theory usually implies conjecture. It is typically a proposed explanation for an unsolved mystery. In science, however, a theory is a mathematic or logical explanation that can be used to reliably predict the outcomes of similar future occurrences. For example, the Theory of Gravity allows us to predict that an apple will fall to the earth. It also tells us that a satellite, if it is traveling fast enough, will orbit the earth. I suppose the apple, if it traveled fast enough, could also orbit the earth; but I digress.
So if theories are supposed to predict similar future occurrences, does it follow that a “Theory of Everything” should predict, well, everything? Sort of.
What physicists aspire to attain in a “Theory of Everything”, or unified theory, is a theory that can account for the force gravity into the mostly reconciled theories of quantum mechanics (really small subatomic stuff) and special relativity (E=mc^2).
Would a unified theory help you predict how your boss will react to your hangover tomorrow? Probably not. In that sense, it isn’t a theory of everything. However, it would make it possible to understand a least a bit more about how our universe began and where we fit into it. On a more practical level, in the same way Einstein’s theories led to nuclear power and space travel, mankind will likely experience similar benefits (and possibly detriments) as a result of any unified theory discovery.
Many possible unified theories have been proposed, the most popular of which are the many variations of String Theory. Unfortunately, much to the consternation of many physicists and other curious observers, up until now the theories have been mostly untestable. That brings us to why that particle accelerator/collider in
What are Hadrons and why will colliding them help lead to a “Theory of Everything”?
In 1995, the CERN Council approved the construction of the world’s largest subatomic particle accelerator and collider to be funded by CERN’s 20 member states. The multibillion euro (or dollar) effort has resulted in a collider housed in a 17 mile circumference tunnel crossing the French/Swiss border twice that sits as far as 450 feet underground.
Simply put, the tunnel contains two pipes that are designed to shoot beams of tiny subatomic particles, broadly referred to as hadrons, but mainly in this case the more commonly known protons, directly at each other in order to observe their interactions before, during, and after moment when the beams collide.
What type of information could come out of proton collisions? Well, it can be explained in a small way by addressing the now universally known equation: E =mc^2. That is to say that Energy = mass * the speed of light squared. By accelerating hadrons at each other to speeds approaching the speed of light, the hadrons will acquire very very high energy levels. The energy released during the particle collision will theoretically generate subatomic particles of masses never before observed by humans. These theoretical particles, often referred to as Higg’s Bosons (alias: God Particle), and their properties are expected to fill gaps in current theories. Physicists hope that the gravity force will finally fit into current understandings of quantum mechanics and relativity.
Looking Back in Time
Many scientists believe that the high energy proton collisions generated by the LHC will replay the moments immediately after the “Big Bang” inception of the universe. Some have gone so far as to call the LHC a time machine. Personally, I think that is a pretty lame comparison. The LHC will no more carry as back in time to the Big Bang than a Battle of Gettysburg reenactment takes us back in time to the Civil War. I think the metaphor preys on the sensibilities of us sci-fi geeks who dream of flux capacitors and warp drives. However, what is important to note is that it is possible that the only way for us to understand the underlying nature of the present state of the universe might be for us to understand its nature at its beginnings.
When Will We Know?
Just last month in May of 2007, press releases told us that the accelerator was virtually completed and that the first experiments to unlock the secrets of the universe would be conducted during the summer of 2007. As recently as last week, however, CERN announced that the experiments would be put off until 2008 because a confluence of minor problems across much of the new equipment.
Some doomsday alarmists don’t mind the delay. Some believe that the LHC at CERN will generate a black hole or some other “un”natural manifestation which will destroy the world or maybe even the universe. While the concept would be great for a Dan Brown book about a lone scientist trying to avert global/universal destruction, most of us can choose to rest easy. Experiences with other colliders in the past seem to indicate that any problems with the experiments can be contained neatly below ground.