In order to dig down into what CERN is all about and why some people are anxious about the organization's activities, we thought the following pro and con approach would be helpful.
PRO: According to our understanding of the universe, the matter we can observe only accounts for about 4 percent of all the matter that exists. Physicists have proposed a kind of substance called dark matter that might make up to 25 percent of the matter in the universe when combined with what we can see. The other 75 percent might come from dark energy. Some scientists at CERN hope the LHC will uncover evidence of dark matter.
CON: The LHC could also produce black holes. A black hole compresses matter into a point of infinite density called a singularity. In general, most people think compressing matter like that constitutes a bad thing -- some worry the black holes generated by CERN could destroy the Earth. CERN scientists say that if the LHC does create black holes, they will be very small, harmless and will decay almost instantaneously.
PRO: CERN might discover a hypothetical particle known as the Higgs boson particle. One of the big mysteries of the universe deals with mass. Why is there mass? What determines if a particle has mass? A theory called the Higgs mechanism says that there may be an as yet undiscovered particle that could explain mass. Controlled collisions within the LHC could produce evidence of this particle.
CON: CERN might unleash a dangerous substance called strangelets upon the Earth. Like the Higgs boson particle, strangelets are purely hypothetical. But unlike Higgs particles, strangelets are really nasty customers. According to some, this stuff could disassemble any matter it comes into contact with and reassemble it into strange matter. One big drawback of this strange matter is that it's lifeless. CERN scientists point out that strangelets have never been observed in nature and that even if they did exist, they'd quickly decay before causing any trouble.
PRO: A further understanding of the universe could lead to amazing practical applications, including time travel! Some physicists theorize that the LHC could become the world's first time machine. They say that time travel to the past might only be possible as far back as to the invention of the first time machine [source: The Telegraph]. Other scientists aren't convinced by these theories, though.
CON: A greater understanding of the universe could allow a future super villain unprecedented access to information that could put us all in jeopardy. Granted, this is a very unlikely scenario, mostly because CERN is not in Metropolis.
In the end, it seems like CERN has everything under control. Their experiments recreate conditions that happen in nature all the time, and the world is still standing. The only difference is that the laboratory conditions are carefully controlled and observed.
Either way, CERN's activities could have a profound effect on us here on Earth. But the rest of the universe is likely to stay the course -- expanding continuously with little regard for what we get up to down here on our planet.
To learn more about CERN and the Large Hadron Collider, follow the links on the next page.