[NetBehaviour] A cosmic hall of mirrors.
marc
marc.garrett at furtherfield.org
Mon Dec 18 16:37:56 CET 2006
A cosmic hall of mirrors.
(Jean-Pierre Luminet )
Most astronomers think that the universe is infinite, but recent
measurements suggest that it could be finite and relatively small.
Indeed, as Jean-Pierre Luminet describes, we could be living in an
exotic universe shaped rather like a football.
At a Glance: Cosmic topology.
• There are three possibilities for the curvature of the universe: space
can be flat, spherical or hyperbolic
• The geometry of the universe depends on its curvature and also on its
topology, which governs the way space is connected and so determines if
it is finite or infinite
• Measurements of the cosmic microwave background constrain the
curvature of the universe and provide hints about its topology
• Recent data suggest that the universe might be multiply connected,
like the left- and right-hand sides of the screen in a computer game
• Since the early 1990s the number of cosmo-topologists around the world
has grown to more than 50.
or centuries the size and shape of space has intrigued the human race.
The Greek philosophers Plato and Aristotle claimed that the universe was
finite with a clear boundary. Democritus and Epicurus, on the other
hand, thought that we lived in an infinite universe filled with atoms
and vacuum. Today, 2500 years later, cosmologists and particle
physicists can finally address these fundamental issues with some certainty.
Surprisingly, the latest astronomical data suggest that the correct
answer could be a compromise between these two ancient viewpoints: the
universe is finite and expanding but it does not have an edge or
boundary. In particular, accurate maps of the cosmic microwave
background - the radiation left over from the Big Bang - suggest that we
live in a finite universe that is shaped like a football or
dodecahedron, and which resembles a video game in certain respects.
more...
http://physicsweb.org/articles/world/18/9/3
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