S3?

Dark matter is just like normal matter but it neither emits nor absorbs light (electromagnetic radiation) or it doesnt absorb enough light to be detected easily. Dark matter can include non-luminous gases, planets, objects condense by black holes, and just about ANYTHING else we cannot detect with electromagnetic radiation. It is only detectable by means of gravitational lensing or other gravitational effects on non-baryonic matter (ie a planet orbiting a star and causing that star to appear to wobble or pulse). There is nothing special about dark matter and it does NOT hold our universe together any more than regular matter does. Dark matter is only a name for matter we cannot detect with light (electromagnetic radiation).

BTW, the universe is expanding and there isnt enough gravity in 3 universes to even come close to slowing it down. What causes this expansion? Dark energy. What causes dark energy? Virtual particles. Virtual particles are constantly popping into and out of existence throughout the universe. The interaction (energy exchanged) between these virtual particles is what we call "dark energy". The virtual particles repel one another (for lack of better terminology) and give rise to the expanding universe. These forces put gravity to shame and it is why the universe does not collapse in on itself. In trillions of years the universe will have expanded so far that even atoms will be ripped apart. This is known as "the big rip"....look it up.

It would be nice if people took the time to understand what scientists claim rather than coming up with half-baked theories.

Gravity is simply a curve in space created by matter (even dark matter). Dark matter IS NOT gravity any more than matter is gravity. When something has mass it creates a "dent" in space. Other objects with mass (if close enough) will feel this "dent" and respond accordingly.

Think of it like being underwater. Water is pressing in on you much in the same way space presses around mass. The difference being that space is curved/dented by mass and that in turn can effect other objects. Any object close enough will tend to roll toward the "dent".

Good explanation, Lee. I was going to type something similar when I got home. I have a good friend working on his post grad studies on the LUX experiment in SD. A lot of what he does sounds really boring but if they are successful it could mean big things.

Dillian, what scope are you using? Saturn on my C8 looks pretty good. Helps to have an autoguider to keep it in view for extended periods of time. This is a picture of my setup minus my DSLR and laptop I use to run it. I remember the first time I saw the moon through a 3.5" refractor. Hooked for life after that. Let alone seeing Jupiter, Saturn, and Mars. I'm working my way up to imaging deep space objects. I've been trying to get the Orion Nebula but I might have to upgrade some of my imaging equipment to get to where I want to be with it.

http://i56.photobucket.com/albums/g1...oala/scope.jpg

Now I have to post my telescope pics when I get home :p Proud owner of an Orion 10" Reflector, Atlas goto mount, Orion ED80 80mm Refractor (my guide scope), Orion G2 (color) and G3 (monochrome) Imaging Camera, 2 auto-guider cameras (forget the models offhand), and about 60 eyepieces and various other accessories. The equipment cost me more than my last car :o

/drool

How is that liberal arts degree treating you?

Some of us aren't obsessed with ourselves.

I've heard the theory the aliens cloaked their civilizations and made themselves virtually undetectable and thus this has led to the theory of dark matter. The problem is the aliens could not hide the gravity influence of their civilization, so one day we may be able to find them by piecing all the dark matter together.

But why? Why hide? Because their civilizations are immense and obvious and spread out everywhere. They would light up the night sky like fireworks. Perhaps by cloaking some things it protects us (or other life) from their presence. It may also protect something else even more important than lifeforms.

There's another theory which postulates there's a galactic or universal agent watching every young civilization - such as ourselves - for signs of expansion into the rest of the cosmos. The mission of this agent is to ensure every participant follows the rules, so that the universe and its history is preserved. So at some point, as we break the chains which bind us to Earth, we will be contacted and given the rules. If we do not abide by them, we will be forced to and may lose our rights temporarily or permanently to exist outside Earth.

Now, all of that belongs in science fiction, and may or may not be plausible.

Here's a good link:
http://www.scilogs.com/the-dark-matt...or/mpawlowski/

My prediction - for the future - is whatever we find out about the universe it'll expand the limits of existence to more and greater things never appreciated in their fullness before. Just as the most informed star gazers 500 years ago were speculating of other earths around other stars, people these days are similarly speculating about things which have yet to be shown to be true, but will undoubtedly bloom and amaze.

Your first theory would require aliens to cloak 73% of all matter in the observable universe. The power required alone would be astronomical. Our puny planet accounts for less than 1% of the total mass of our solar system. If we wanted to hide Earth why would we hide 72.8% more mass than we had to? That would make detection trivial simply by watching the wobble of our sun. A hidden planet our size is near undetectable on its own.