CERN opens its doors to the world

On 6 April 2008, CERN(1) will open its doors to the public, offering a unique chance
to visit its newest and largest particle accelerator, the Large Hadron Collider

(LHC), before it goes into operation later this year. This scientific instrument,
the largest and most complex in the world, is installed in a 27km tunnel, 100 metres
underground in the Swiss canton of Geneva and neighbouring France. CERN will open
all access points around the ring for visits underground, to the tunnel and the
experiment caverns. On the surface, a wide-ranging programme will be on offer,
allowing people to learn about the physics for which this huge instrument is being
installed, the technology underlying it, and applications in other fields.

In the LHC, particles such as protons or heavy ions will be accelerated to close to
the speed of light in two tubes. At four intersection points the particles will
collide at an energy never before reached in a particle accelerator to study new
areas of physics that so far have not been accessible. Experiments at the LHC expect
to be able to answer a number of fundamental questions, such as the origin of mass
or the nature of the so-called "dark matter". However, since the LHC will explore a
new energy range, there will also be unexpected results, resulting in new questions
and new physics.

On the Open Day, many visitors to CERN will be able to descend and see the LHC and
its big experiments, ALICE, ATLAS, CMS and LHCb in place in their underground
caverns. However, since access to the underground areas is limited due to the
capacity of the elevators and safety concerns, a range of activities is also planned
on the surface where visitors will be able to learn about particle physics and talk
to CERN engineers and physicists.

A central theme apart from the LHC, its magnets and experiments, will be
superconductivity, the principle on which the operation of the LHC is based. At the
heart of the LHC magnets lie 7000 kilometres of superconducting cables, cooled to a
temperature close to absolute zero, which are able to conduct electricity without
resistance. Spectacular experiments, exhibitions and films will introduce the public
to this exciting phenomenon, visitors will be able to meet physicists to "ask an
expert" and there will be the chance for an encounter with two Nobel laureates who
will give lectures about their prize-winning discoveries.

The fun and excitement of physics will be demonstrated in the Globe of Science and
Innovation and physics shows taking place at various venues around the ring.
Children will be able to meet up with the presenter of a popular French TV show on
his tour through eight communes close to the LHC access points or take part in a
"magical physics" show.

More details on the programme and additional information can be found on the CERN
website at

Notes to the editor:
A Press Welcome point will be set up in the Globe of Science and Innovation
( in front of the CERN
Meyrin main site.