Free Republic
Browse · Search
News/Activism
Topics · Post Article

To: Physicist; PatrickHenry
It seems to me this team has taken a giant leap backwards to the time when dark matter and dark energy were treated as the same thing.

The more recent articles I've read make a huge distinction between the two with regard to gravity. Dark matter, like black holes, has the property of high positive gravity (center of the galaxy, etc.) Dark energy, OTOH, has the property of negative gravity, e.g. the "vacuum" of space between galaxies, causing the acceleration of the universe.

12 posted on 03/17/2004 8:32:10 AM PST by Alamo-Girl
[ Post Reply | Private Reply | To 4 | View Replies ]


To: Alamo-Girl
It seems to me this team has taken a giant leap backwards to the time when dark matter and dark energy were treated as the same thing.

I don't think they were ever treated as the same thing.

The more recent articles I've read make a huge distinction between the two with regard to gravity. Dark matter, like black holes, has the property of high positive gravity (center of the galaxy, etc.) Dark energy, OTOH, has the property of negative gravity, e.g. the "vacuum" of space between galaxies, causing the acceleration of the universe.

Well, there isn't any negative gravity; it's the same old gravity that causes that repulsive effect when the vacuum itself has an energy density. Analogously, the bubbles in your glass of Yuengling Lager aren't accelerated away from the center of the Earth because of anti-gravity, but because of gravity. It's not the same effect, but it gives you the idea. Mmm, Yuengling.

I guess I'm not really seeing why you think dark energy is considered to be behaving differently in this case.

13 posted on 03/17/2004 8:49:08 AM PST by Physicist
[ Post Reply | Private Reply | To 12 | View Replies ]

Free Republic
Browse · Search
News/Activism
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson