I just finished with Galileo's Sidereal Messenger/ Kepler's Dioptics for the umpteenth time and I marvel at the discoveries made in those first few years after the invention of the telescope. Galileo got so many things right with his observations but the genius Galileo got a slew of things wrong too. Johannes Kepler the wunderkind that came up Kepler's three Laws of Planetary Motion, got his share of stuff wrong. Some cases in point with these two giants are...Galileo was trying to figure out why the edge of the moons disk appeared smooth and the rest of the Moon was littered with mountains and valleys. Galileo wrote: To this explanation may be added another, namely, that there is round the body of the Moon, just as round the Earth, an envelope of some substance denser than the rest of the ether, which is sufficient to receive and reflect the Sun s rays, although it does not possess so much opaqueness as to be able to prevent our seeing through it—especially when it is not illuminated. That envelope, when illuminated by the Sun's rays, renders the body of the Moon apparently larger than it really is, and would be able to stop our sight from penetrating to the solid body of the Moon, if its thickness were greater; now, it is of greater thickness about the circumference of the Moon, greater, I mean, not in actual thickness, but with reference to our sight-rays, which cut it obliquely; and so it may stop our vision, especially when it is in a state of brightness, and may conceal the true circumference of the Moon on the side towards the Sun. This may be understood more clearly from the adjoining figure, in which the body of the Moon, A B c. is surrounded by an enveloping atmosphere, D E G. An eye at f penetrates to the middle parts of the Moon, as at a, through a thickness, dia, of the atmosphere; but towards the extreme parts a mass of atmosphere of greater depth, E B, shuts out its boundary from our sight. Galileo, using the data he had acquired, was way off base with this solution. Galileo also originally and erroneously thought Saturn was a triple system with two smaller planets on either side of the planet.This is from the preface of Kepler's Dioptics. : For if the earth were banished from the centre of the universe, some fear lest the water should leave the orb of the earth and flow to the centre of the universe ; and yet we see that in the moon, as well as in the earth, there is a quantity of moisture occupying the sunken hollows of that globe ; and although this orb revolves actually in the ether, and outside the centres not merely of the universe, but even of our earth, yet the mass of water in the moon is not at all hindered from cleaving invariably to the orb of the moon, and tending to the centre of the body to which it belongs. So Kepler thought that the Moon had water on it lots of water. Hmmm The Moon does have water but not where he said and not how much he said.
That is the problem with RAW data. The interpretations are as varied as the Universe itself. That might be a little over the top but you definitely get my meaning. They can be varied using the same science available to any thinking human being. This is where Dark Matter /Dark energy comes in. Can it be explained by just baryonic sources such as Brown dwarfs, black holes and the like. Or just maybe it is non baryonic in nature? So if it is non baryonic, is it cold, warm or hot Dark matter? If it is one of those three, could the particles be neutrinos super-neutrinos or even neutralinos. or maybe weakly interacting massive particles etc. or how about theoretical partcles yet to be found? By the way it could be a combination of some or all of the above... or none of it.
It could be one of several gravity theories floating out there (paradox intended) Modified Newtonian dynamics ie MOND, TeVes, MOG NGT and back reaction theory etc. each one might include the some quantity of Dark Matter to shore up it's point. The latest MOG theory is stand alone in nature. there are many others out there clamoring to stay off the trash pile of dis-proven theories.
I have seen mandates that call for a solution in the next two years or science will have to reevaluate the whole Dark "stuff" scene. I have seen the Ether come up to explain some of this circa 2006? Are you kidding me? Do I have a favorite theory? Well, yes I do but my vote hardly counts. What does count is the hard working scientist of this age striving to make sense out of the many Terra-bites of information continuing to be gathered by oh so many sources. Two years is a short time to sort out all of this.One thing is for certain these next couple of years are sure to be exciting! For the many theories that will go by the way side just remember you are in some very good company.
Until next time
Keep looking up!