文档介绍：New quasar studies set stringent limit
EUROPEAN SOUTHERN OBSERVATORY NEWS RELEASE
Posted: April 3, 2004
Detecting or constraining the possible time variations of fundamental physical constants is an
important step toward plete understanding of basic physics and hence the world in which we
live. A step in which astrophysics proves most useful.
Previous astronomical measurements of the fine structure constant - the dimensionless number
that determines the strength of interactions between charged particles and ic fields -
suggested that this particular constant is increasing very slightly with time. If confirmed, this
would have very profound implications for our understanding of fundamental physics.
New studies, conducted using the UVES spectrograph on Kueyen, one of the -m telescopes of
ESO's Very Large Telescope array at Paranal (Chile), secured new data with unprecedented
quality. These data, combined with a very careful analysis, have provided the strongest
astronomical constraints to date on the possible variation of the fine structure constant. They show
that, contrary to previous claims, no evidence exist for assuming a time variation of this
fundamental constant.
A fine constant
To explain the Universe and to represent it mathematically, scientists rely on so-called
fundamental constants or fixed numbers. The fundament