No, that's not a Death Star under construction -- it's the Large Hadron Collider at CERN, featured in a great slideshow over at SEED. The world's largest particle accelerator, it will open in November 2007, barring any Big Dig-style catastrophe. Wikipedia says 2,000 scientists are building this thing primarily to answer the following questions:
- Is the popular Higgs mechanism for generating elementary particle masses in the Standard Model violated? If not, how many Higgs bosons are there, and what are their masses?
- Will the more precise measurements of the masses of [protons, neutrons, and other "heavy" subatomic particles] continue to be mutually consistent within the Standard Model?
- Do particles have supersymmetric ("SUSY") partners?
- Why are there violations of the symmetry between matter and antimatter?
- Are there extra dimensions, as predicted by various models inspired by string theory, and can we "see" them?
- What is the nature of the 96% of the universe's mass which is unaccounted for by current astronomical observations?
- Why is gravity so many orders of magnitude weaker than the other three fundamental forces?
I'm not sure I understand what Higgs bosons are, but I do know that second-to-last question refers to "dark matter," which you'll be able to read about in an upcoming issue of mental_floss.