how can something we can't see as dark matter really exist?

Have you seen that movie, Dark Matter starring Meryl Streep? That movie was based on actual events. Perhaps research on the Chinese physicist Gang Lu might shed insight on your inquiry.

The problem with your average galaxy is that there is no way to account for it's motion (ie: spiraling) without adding an extremely large amount of extra (apparently unseen) matter to its size, like 10 times it size. For example, take the Milky Way. For it to spiral like it does there is simply not enough matter for it to do so. According to computer simulations the Milky Way should either break apart or actually be much much larger than it is. And not by just a few planets and suns, it's short of visible matter many millions of times its own mass. I find it helps to think of dark matter as a sink full of water and your average galaxy as the left over dish soap after washing dishes. When you pull the plug, the water begins to circle down the drain and the soap forms into a spiral on top. The waters motion directly affects the shape of the soap and gives the soap it's form. Dark Matter acts in the same way towards a galaxy. Except (as you point out) DM has not yet been seen or detected which just means science does not have the complete rule book on light and as such doesn't know of the wavelengths necessary to "see" dark matter. Simply put, Just because we haven't seen it doesn't mean it doesn't exist, it just means we haven't figured out "how" to see it yet. Hope this helps somewhat

Planets (and in fact everything that isn't a star) account for only a tiny fraction of the total mass of a stellar system. Visible matter only accounts for 1/4 of the total mass of galaxies. Neither planets nor black holes have enough mass to explain this discrepancy.

Dark matter so far offers the best explanation for observational data even if its exact nature is not understood. Whatever it is, it seems to provide an invisible "scaffolding" for the structure of galaxies and clusters of galaxies.

ADDED: I'm not confusing black holes with dark matter. Don't you confuse non-luminous planets with dark matter either. I'm merely saying that NEITHER of these can account for the observed effects of dark matter.

I am no wizard or scientist, however dark matter is not the only force we can not see. Scientist want us to think of dark matter as another aspect of gravity. I suggest it may be the lack of gravity releasing the force of the universe that allows it to increase it's seperation from surrounding matter. As if to say the universe has travelled so far from it's origin and other gravity inducing material (suns, stars, etc) that the actual force of the gravity that was present and binding at first, is waning, allowing the 'pushing' force to 'push' with less resistance. OR that the increased gravity from other 'nearby' clusters of material is pulling us with an increased effect as we join the 'cotton-web' of galaxies that prevade the universe. Of the two, I think the latter is the more logical. just my $.02

Well from what I understand, there are only a few states of matter that we, as humans, can relate to. The most obvious being solid, liquid and gas. Dark Matter is neither of these, as it is not a solid structure, neither liquid, but it cannot be a gas either as space is an airless space. Even though dark matter is still a theory, from what we know right now it sounds likely that it exists as it ties up a lot of loose ends.

"i'm asking if there is any info for it, apart from the extra desirable gravitational pull between the galaxy." i do no longer understand what you recommend by using "the extra desirable gravitational pull between the galaxy.". "no rely if or no longer it incredibly is feasible that area-time curvature can clarify the extra desirable gravitational pull" it incredibly is like announcing something's heavier with the aid of fact it weighs extra. So what info is there that something's there ("dark rely" is in basic terms a label):- Galaxy clusters are extra massive than their luminosity exhibits Galactic rotation curves do no longer coach a Keplerian decay Dwarf galaxies in galaxy clusters are extra stable than they might desire to be - they might desire to be torn aside by using their neighbours Gravitational lensing exhibits that there is something there that we won't see None of it incredibly is opinion - it incredibly is observational info. additionally, laptop fashions of galaxy and galaxy cluster formation do no longer paintings without some variety of dark rely. The characteristics of the dark rely may well be distinctive and the outcomes in comparison with observations.

dark matter bends light

Have a look at this, it might give you an idea.

http://www.youtube.com/watch?v=PNpa6z2YXXE&feature...