Rumors of a Dark Universe
Explanation:
Twenty-one years ago
results were
first presented indicating that most of the energy in our
universe is not in stars or galaxies but is tied to space itself.
In the language of cosmologists, a large
cosmological constant -- dark energy -- was directly implied by new distant
supernova observations.
Suggestions of a
cosmological constant were
not new -- they have existed since the advent of
modern relativistic cosmology.
Such claims were not usually popular with astronomers,
though, because dark energy was so unlike known
universe components, because
dark energy's abundance appeared limited by other observations,
and because less-
strange cosmologies
without a signficant amount of dark energy
had previously done well in explaining the data.
What was exceptional here was the seemingly direct and reliable method of the observations
and the good reputations of the
scientists conducting
the investigations.
Over the
two decades, independent
teams of astronomers have continued to accumulate data
that appears to
confirm the existence of
dark energy and
the unsettling result of a presently
accelerating universe.
In 2011, the team leaders were
awarded the Nobel Prize in Physics for their work.
The
featured
picture of a supernova
that occurred in
1994
on the outskirts of a
spiral galaxy
was taken by one of these collaborations.
News:
APOD is now available via
Facebook in Hindi.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
