I think it is the Large Hadron Collider
It can do the following that can destroy the either the Earth or the UNIVERSE:
1) Time Travel
2) Strange Matter
3) Recreating the Big Bang
1) What Could Possibly Go Wrong?
Of course, there are plenty of ways in which the universe can screw us for daring to violate that most fundamental of laws, cause and effect. We can't even imagine them until we know the first thing about time travel, which we don't. But some speculate that the very attempt to travel back in time could result in the world exploding, imploding, collapsing, shrinking into a singularity, or simply disappearing. But because I strive to bring you only the weirdest of possibilities, so consider the chronological collapse scenario. In the distant future, when the stars have burned out and the planets have wobbled out of their celestial orbits, the descendents of humanity will be staring extinction in the face, and if they have access to a **** time machine then it's likely they're going to say "screw this" and just return to a more comfortable point in history. A flood of refugees from the future might set up home in the present and flourish, until the world ends again and they decide to do what worked last time. And again. And again. Effectively, the moment we switch on our very first time machine, our universe is going to be home to approximately infinity refugees from the future. You do the math.So, Basically It's Like... http://www.youtube.com/watch?v=9XfVl6_R7_k
According to some Russian scientists, yes. Sure, there are no serious plans in motion to research into building time machines, but who says it has to be deliberate? The discovery of penicillin was a complete accident. The theory is that the LHC might open wormholes with its high-energy collisions that future generations can manipulate for time travelling purposes. Apparently it's possible that those Swiss eggheads will switch on the machine only to find a naked Arnold Schwarzenegger asking for their clothes. You may be thinking, "If we get a time machine, and realize it will destroy the universe, then all we'd have to do is travel back in time and destroy the time machine! Easy!". But then...if we destroyed the time machine, then we wouldn't be able to go back in time... so the machine would remain intact, in which case we could use it to go back and... Look, we don't know. Screw science.
2) What Could Possibly Go Wrong?
There are two hypotheses about strange matter. One is that the stuff will simply disappear a fraction of a second after it appears. The other is that it will stabilize and convert every atom it comes in contact with into more strange matter. It could go either way, really. There's a theory that there are entire stars out there in the universe that are made out of strange matter, just because a microscopic fragment of the stuff made contact once and then everything went to hell. Now imagine, just theoretically, if some of this strange matter should appear on Earth. And, just theoretically, it should be stable enough to start a reaction with regular matter. Theoretically, we'd all be dead as hell.So, Basically It's Like...
Imagine you're like the fabled King Midas, and you have the power to convert matter with a single touch. Except that instead of gold, everything you touch turns into crap. And everything it touches turns to crap. Before you know it, the whole world is crap, and it's all your fault.
That's right, our friends at the LHC project expect a lot of weird things to pop up when they start smashing atoms together, and strange matter is one such possibility. That's why scientists have written papers with boring titles such as Will Relativistic Heavy-ion Colliders Destroy Our Planet?, the rebuttals to which were basically, "Let's turn them on and find out!" At this point we're kind of wondering whether there's anything this machine can do that doesn't involve killing you and everyone you care about. Scientists respond to the strange matter problem by saying if it was ever going to happen, it would have happened already (since these kind of reactions happen a zillion times a second in our atmosphere anyway). We like to call this piece of rhetoric the cop-out hypothesis, because they know pretty well that if it turns out they're wrong, there won't be anyone left to sue them.
3) What Could Possibly Go Wrong?
Well, first imagine an apocalyptic nuclear holocaust. Multiply that by about one hundred and twenty thousand billion, and then multiply that by around the neighborhood of infinity. That equals around one eighth of the magnitude of the Big Bang. Nevertheless, scientists are pretty sure they can contain their Big Bang in an erlenmeyer flask, just so long as they remember to cork it.So, Basically It's Like...
Imagine you have a huge tanker truck parked outside a children's hospital. You don't know what's inside it, but you're fairly confident that it's either a cure for cancer, or 20,000 gallons of explosive nitroglycerin. To find out which, you have to shoot at it with an AK-47.
The problem, of course, is that even the eggheads don't really know what's going to happen, which is sort of why they're doing it in the first place. That's also why a lawsuit was filed to put a stop to it. Scientists on the LHC project insist there is no danger, and predict that the resulting observations could revolutionize science and send us into a golden age of knowledge, in the event that we actually survive. Experts assure us that based on everything we know about science, the chances of doom are fairly slim. Experts also say LHC will change everything we know about science. So there is a certain chance that one of the brand new things they learn about the LHC is that the LHC has the ability turn the entire planet into a fine cloud of particles.Expletive deleted per poster request -PtA