RE: No dark matter?
April 20, 2011 at 8:47 am
(This post was last modified: April 20, 2011 at 8:48 am by lilphil1989.)
(April 20, 2011 at 7:43 am)alemcodon Wrote: If dark matter does exist then is it at a perfect balance in EVERY galaxy, from trillions of billions of galaxies, where it keeps order and prevents mass mayhem. Why is it not in some galaxies the stars on the outer edge could be going too fast, or too slow? (thus causing mayhem and 'randomness' - in which our universe is built???)
Dark matter is nothing to do with 'keeping order'. If you're going to argue against something, at least make sure you actually understand what you're arguing against.
(April 20, 2011 at 7:43 am)alemcodon Wrote: Next youll be saying dark matter is relative to matter....? Then why not the matter in our solar system? why only on a galactic scale?
The interstellar spaces between star relative to stellar masses are orders of magnitude greater than the spaces between solar system planets relative to planetary masses.
Therefore, the mass density of the solar sytem is considerably greater than the average galactic density. So the solar system is (relatively) more strongly gravitationally bound than a galaxy, allowing the influence of any homogeneous, gravitationally interacting matter field to have a much more obvious effect on galactic dynamics than on solar system dynamics.
(April 20, 2011 at 7:43 am)alemcodon Wrote: Ich bin muslim (yeah yeah save your curses for an anti islamic forum)....the quraan tells us angels are keeping order in the stars - so my personal belief would therefore be this order is being kept by angels, and not dark energy/mass. Although it would be feasible to decsribe the angels as dark energy since we cannot see them, and they have a impact/force which cannot be seen or measured.
Angels are described as being made of 'light', which is kinda like a metaphore as humans are made from 'earth', although our mass is physically from the earth, it is not just mud we're made from, so angels are made from light, or various components of light.
Quraan also tells us the angels travel in 1 earth day the same distance as the moon in 10,000 years, if you derive a speed from there the answer is 299,999.457m/s. So if the book written 1400 yrs ago tells me that, then when it says angels regulate the stars, i believe it.
Nice try, but false.
Firstly, one of the observable quantities you need to make that calculation is the average orbital radius of the moon. Since your value is given to 9 significant figures, it must follow that you know the average lunar orbital radius to the same number of significant figures. And we simply don't know it to that degree of precision.
Secondly, let's actually do the calculation.
Taking the average lunar orbital radius as 0.38 megametres and the orbital period as 27.3 days, all you need to do is find the circumference of the moons orbit, 2*pi*r, multiply by 10000years(converted to days)/27.3days to get the number of orbits in 10000 years and divide that by the number of seconds in a day.
What you get is 3.3*10^9, which is 10 times too large. For a more accurate calculation you would also need to account for the motion of the earth around the sun, and the motion of the sun around the galactic centre, which would only increase the distance travelled by the moon, thus increasing your calculated speed.
But if you'd actually bothered to do the calculation for yourself instead of being a credulous idiot that repeats everything the Imam tells him in parrot fashion, you'd know that.
(April 20, 2011 at 7:43 am)alemcodon Wrote: It has also told us about the big bang, the steadily expanding universe, how the heavens and the earth were once joined but are now split, and also the numerous forms of life between earth and the heavens which we will never see.
Yeah sure, and by the same kind of dishonest interpretation, Nostradamus also predicted my next bowel movement.
Galileo was a man of science oppressed by the irrational and superstitious. Today, he is used by the irrational and superstitious who claim they are being oppressed by science - Mark Crislip