Scientists at The University of Manchester have discovered a new way to test
Einstein's theory of relativity using the 'lead' of a pencil.
Until now it was only possible to test the theory
by building expensive machinery or by studying stars
in distant galaxies, but a team of British, Russian
and Dutch scientists has now proven it can be done
in the lab using an ultra-thin material called Graphene.
The group, led by Professor Andre Geim of the School
of Physics and Astronomy, discovered the one atom
thick material last year. Graphene is created by
extracting one atom thick slivers of graphite via
a process similar to that of tracing with a pencil.
Geim, said: "To understand implications
of the relativity theory, researchers often have
to go considerable lengths, but our work shows that
it is possible to set up direct experiments to test
relativistic ideas. In theory, this will speed up
possible discoveries and probably save billions of
pounds now that tests can be set up using Graphene
and relatively inexpensive laboratory equipment."
In a paper published in Nature (November 10, 2005),
the team describes how electric charges in Graphene
appear to behave like relativistic particles with
no mass (zero rest mass). The new particles are called
massless Dirac fermions and are described by Einstein's
relativity theory (so-called the Dirac equation).
The team also reports several new relativistic effects.
They have shown that massless Dirac fermions are
pulled by magnetic fields in such a manner that they
gain a dynamic (motion) mass described by the famous
Einstein's equation E=mc2. This is similar to the
case of photons (particles of light) that also have
no mass but can still feel the gravitational pull
of the Sun due their dynamic mass described by the
Kostya Novoselov, a key investigator in this research,
added: "The integer and fractional quantum
Hall effects are two of the most remarkable discoveries
of the late 20th century. It is not easy to explain
their significance but both discoveries led to Nobel
prizes. One can probably appreciate the importance
of our present work in terms of fundamental physics,
if I mention that one of the phenomena we report
is a new, relativistic type of the quantum Hall effect."
Contact: Simon Hunter
University of Manchester