Astronomy Problem! help!?
What is the evidence for dark matter? What is the dark matter that surrounds galaxies made up of? Based on your research, in your opinion, does the evidence of the observed phenomena attributed to dark matter actually point to an extension of gravity?
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A long time ago, astronomers calculated how fast stars should be orbiting the centers of their galaxies. What they found was that the stars motion was *much* too fast for how much matter was present - they were in orbit, but they should be flying out & away.
The only thing that would allow them to stay in orbit was mass that couldn't be seen - so-called "Dark Matter" - because they don't know what it is... yet.
"And extension of gravity"....? Not sure what this means.... We know very well how mass affects space - gravitational pull is the result of the warping of space by matter. We know how much mass a planet or star has by the speed with which it's moons or planets orbit it. ****Unless the law of gravity changes elsewhere in the cosmos*****, then the effect we see must be caused by some sort of unseen matter, or different, massive particle we're unable to perceive (at least so far...)
are you in todds astronomy class at ccsf?