Large Hadron Collider[LHC]
[1] 
[2] 
[3]
[1] Superconducting quadrupole electromagnets are used to direct the beams to four intersection points, where interactions between accelerated protons will take place.
[2] CMS detector for LHC [3]LHC-experiment
The Large Hadron Collider (LHC) is the world’s largest and highest-energy particle accelerator. It is expected to address some of the most fundamental questions of physics, advancing the understanding of the deepest laws of nature.
List of unsolved problems in physics
This is a list of some of the major unsolved problems in physics. Some of these problems are theoretical, meaning that existing theories seem incapable of explaining a certain observed phenomenon or experimental result. The others are experimental, meaning that there is a difficulty in creating an experiment to test a proposed theory or investigate a phenomenon in greater detail.
Theoretical problems
The following problems are either fundamental theoretical problems, or theoretical ideas which lack experimental evidence and are in search of one, or both, as most of them are. Some of these problems are strongly interrelated. For example, extra dimensions or supersymmetry may solve the hierarchy problem. It is thought that a full theory of quantum gravity should be capable of answering most of these problems (other than the Island of stability problem).
Quantum gravity, cosmology, and general relativity
Why does the predicted mass of the quantum vacuum have little effect on the expansion of the universe?
Can quantum mechanics and general relativity be realized as a fully consistent theory (perhaps as a quantum field theory)?[1] Is spacetime fundamentally continuous or discrete? Would a consistent theory involve a force mediated by a hypothetical graviton, or be a product of a discrete structure of spacetime itself (as in loop quantum gravity)? Are there deviations from the predictions of general relativity at very small or very large scales or in other extreme circumstances that flow from a quantum gravity theory?
Black holes, black hole information paradox, and black hole radiation
Do black holes produce thermal radiation, as expected on theoretical grounds? Does this radiation contain information about their inner structure, as suggested by Gauge-gravity duality, or not, as implied by Hawking‘s original calculation? If not, and black holes can evaporate away, what happens to the information stored in them (quantum mechanics does not provide for the destruction of information)? Or does the radiation stop at some point leaving black hole remnants? Is there another way to probe their internal structure somehow, if such a structure even exists?
See-details-click=http://en.wikipedia.org/wiki/Unsolved_problems_in_physics
Why the LHC and STANDARD model
A few unanswered questions…
The LHC was built to help scientists to answer key unresolved questions in particle physics. The unprecedented energy it achieves may even reveal some unexpected results that no one has ever thought of!
For the past few decades, physicists have been able to describe with increasing detail the fundamental particles that make up the Universe and the interactions between them. This understanding is encapsulated in the StandardModel
[click=http://user.web.cern.ch/public/en/Science/StandardModel-en.html] of particle physics, but it contains gaps and cannot tell us the whole story. To fill in the missing knowledge requires experimental data, and the next big step to achieving this is with LHC.
[details-click=http://user.web.cern.ch/public/en/LHC/WhyLHC-en.html
sgisjr's notes,references & writtings 
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