You must be thinking. Another of those rumours about the Earth
being destroyed on 12 Dec 2012?
This, ladies and gentlemen, is different. Large Hadron Collider is
the world's most powerful particle accelerator located in a tunnel
under France and Switzerland.
Purpose of this experiment?
Beyond revealing a new world of unknown particles, the LHC
experiments could explain why those particles exist and behave as
they do. The LHC experiments could reveal the origins of mass, shed
light on dark matter, uncover hidden symmetries of the universe,
and possibly find extra dimensions of space.
What has this gotta do with
Doomsday?
During this course of experiment, there
will be production of micro black holes, and strangelets,
potentially resulting in a doomsday scenario. The risk of a
doomsday scenario was indicated by Sir Martin Rees as being at
least a 1 in 50,000,000 chance and by Professor Frank Close, with
regards to (dangerous) strangelets, that "the chance of this
happening is like you winning the major prize on the lottery 3
weeks in succession; the problem is that people believe it is
possible to win the lottery 3 weeks in succession. Accurate
assessments of these risks are impossible due to the present
incomplete, or even hypothetically flawed, standard model of
particle physics.
What are Mirco Black Hole and
Strangelets?

Let's Countdown to it.
http://www.lhcountdown.com/
I know all these sounds very complicated, at first it did to me,
but these links below might help you get a better picture.
http://en.wikipedia.org/wiki/Large_Hadron_Collider
http://www.uslhc.us/What_is_the_LHC
http://public.web.cern.ch/public/en/LHC/HowLHC-en.html
A video to add on...
http://ted.streamguys.net/BrianCox_2008_480.mp4
Don't freak out yet. Chances of the experiment going wrong is 1
in 50,000,000 chance. So if this experiment succeeds, the next one
we will be looking out for would be 12 Dec 2012.
If the Earth is to die tomorrow, just die lor. Worry for what? As
if we can escape the catastrophe by travelling to other nearby
planet.