One of my favorite science quotes is comprised of two words from Galileo Galilei: "oculate certitudine"...which loosely translates as "visible certainty." More below on why these two simple words changed the nature of science.
Modern science is evidence driven, hypothesis-based experimentation confirmed by replication. Science deals with testable hypotheses in the natural world. You must use data obtained in a reasonable and confirmable way to advance your ideas. If you claim secret information or no one else can replicate your findings, your ideas are ignored and rapidly fade away.
You may think it has always been that way, and it seems entirely rational way to think about nature and science: observe something and record what you see. It hasn’t always been that way.
"Oculata certitudine." Visible certainty. Galileo Galilei published those two words in 1610 in his treatise "Sidereus Nuncius."
The whole quote is:
In Latin:
"Quod tertio loco a nobis fuit observatum, est ipsiusmet LACTEI Circuli essentia, seu materies, quam Perspicilli beneficio adeo ad sensum licet intueri, ut et altercationes omnes, quæ per tot sæcula philosophos excruciarunt, ab oculata certitudine dirimantur, nosque a verbosis disputationibus liberemur. Est enim GALAXIA nihil aliud, quam innumerarum Stellarum coacervatim consitarum congeries: in quamcumque enim regionem illius Perspicillum dirigas, statim Stellarum ingens frequentia sese in conspectum profert, quarum complures satis magnæ ac valde conspicuæ videntur; sed exiguarum multitudo prorsus inexplorabilis est."
English translation:
"What was observed by us in the third place is the nature of the Milky Way itself, which, with the aid of the spyglass, may be observed so well that all the disputes that for so many generations have vexed philosophers are destroyed by visible certainty, and we are liberated from wordy arguments. For the Galaxy is nothing else than a congeries of innumerable stars distributed in clusters..."
It was a push for evidence-based science to dispute dogma. To be believed, your information must be publicly available, credible, and easily explainable. While Galileo is well known for many scientific findings, it was his meticulous attention to detail and data recording that made it all possible. His data was so powerful that it was "liberated from wordy arguments."
Galileo carefully documented many heavenly objects through his telescope including Saturn’s rings, sun spots, and Jupiter’s moons, but it was his findings on Venus’ phases that allowed him to make the seemingly innocuous statement: "e queste diversita nascono dal movimento annuo della Terra." This translates to "...and these difference are born of the annual movement of the Earth."
"The annual movement of the Earth"...those few, simple words were dangerous indeed. The geocentric model of the universe was central to the Catholic Church dogma at the time. This was seen as a challenge to Church authority. While the heliocentric model was certainly not a new concept (Copernicus published his heliocentric theory over 60 years earlier near the time of his death, so he was not personally subjected to the wrath of the Church), it was Galileo’s observations that gave direct evidence for Copernicus’ theory. His observational findings and drawings directly contradicted over a thousand years of known "fact" according to scripture.
So just what did the Scripture actually say to support a geocentric model? You might be surprised at the few verses used to support this view:
"the world is firmly established, it cannot be moved" Psalm 93:1, Psalm 96:10, Chronicles 16:30
"(God) set the earth on its foundations; it can never be moved." Psalm 104:5
"the sun rises and the sun sets, and hurries back to where it rises." Ecclesiastes 1:5
Galileo argued that the scriptures weren’t wrong, just the interpretation by the Church was incorrect. He believed in a figurative interpretation, not the literal interpretation by the Church. This was still controversial because many believed the Bible to be inerrant.
While the original treatise was controversial, it wasn’t until after Galileo published his "Dialogue Concerning the Two Chief World Systems" at the behest of Pope Urban VIII did the full focus of the inquisition fall onto him. Faced with ex-communication, imprisonment, and possibly torture, Galileo publicly recanted his heliocentric findings. Galileo was subjected to house arrest for the duration of his life. Although the Church officially reversed its prohibition against heliocentrism in 1758, it wasn’t until a statement made by Pope John Paul II in 1992 that the Church formally apologized for its treatment of Galileo.
I think especially in this day and age, given the Bush Administration's battles against science, we should remember the power of evidence-based science. Scientists need to communicate more effectively with Society. Ultimately, the power to change course depends upon an educated populace that votes in an informed manner.