Is dark energy uniformly distributed throughout the universe, even at
cosmic scales? I have not read that claim before, so I'm not sure if it
is true or false. What data support the claim of uniform distribution?
I've also read that the amount of dark energy is increasing, at least
relative to the amount of baryonic matter and dark matter. This claim
was made in the context of the total mass-energy density of the universe
being the critical density for a flat universe. I'm not sure if that
means that the density will increase beyond the critical density. If
the total density increases due to an increase of dark energy, what does
that imply about the ultimate fate of the universe? In the absence of
dark energy, a supercritical density implies a Big Crunch, but dark
energy increases the rate of expansion.
Daniel Crowe
Oklahoma School of Science and Mathematics
Ardmore Regional Center
dcrowe@sotc.org
-----Original Message-----
From: Forum for Physics Educators [mailto:PHYS-L@list1.ucc.nau.edu] On
Behalf Of STRatliff@NWC.EDU
Sent: Monday, January 10, 2005 10:53 AM
To: PHYS-L@LISTS.NAU.EDU
Subject: [PHYS-L] Basic Facts About Dark Energy
Dear PHYS-L,
I've been thinking about dark energy, and have come up with a simple
list
of its properties. I am trying to come up with a list of properties
that
is both correct but also in simplified form for non-scientists to
understand.
Would you please comment on the statements below and let me know if I
have
left anything out, or made any mistakes.
If dark energy exists, it has the following properties:
1. It exists uniformly throughout the universe.
2. It makes up most of the energy of the universe.
3. Unlike other forms of energy (visible light, sound, radio waves,
etc.), it cannot be directly detected.
4. It causes empty space to repel itself.
Thank you,
Steven Ratliff
Steven T. Ratliff
Institutional Researcher / Professor of Physics
Northwestern College
3003 Snelling Ave. N.
St. Paul, MN 55113-1598
U. S. A.