'Consensus' science embedded in late 19^th century textbooks and dogma, clearly presented the medieval period as an irrational epoch in which the vast majority of people believed in a flat-earth. This is an utter lie of course. No one after the time of Christ, who was remotely educated or alert, believed in the flat disc theory, a few cranks and misfits excepted. Historian Garwood has compiled an interesting account of the 'flat earth' beliefs, how they came about and why even today some people – such as the atheist-evolutionist who is President of the Flat Earth Society – still believe in them.

'Consensus' history about science in the Medieval period is remarkably ignorant.

“..educated medieval people did not believe the earth to be flat, and it was neither Columbus’s intention nor the outcome of his voyage to demonstrate to doubters that it was a globe.”

“Columbus’s contemporaries assumed that it was spherical – indeed, the point was far beyond any sort of dispute – many believed that the stretch of water between Europe and Asia was uncrossable and sailors risked becoming stranded or running out of food.5 Under these circumstances, what is widely assumed to be his greatest achievement is a chimera: no educated person in fifteenth-century Europe would have imagined that Columbus was bound to sail off the edge of the world.”

Propaganda from Humanists aka Atheists and Naturalists, is not fact:

“Italian humanists, set on glorifying the literary achievements of classical antiquity and their role as restorers of this golden age, likewise promoted the idea that the time that went before them was an era of intellectual stagnation and gloom.”

“Enlightenment propaganda, hope and optimism pervaded the age, and man was depicted as master of his own fate: through rational empirical investigation, it was said, humankind could be improved and progress and perfectibility were achievable. Such endeavours were to be founded on critical thinking; reason and empiricism were posted as the new brooms that would sweep society clean of irrational and outmoded beliefs and institutions.”

From Pythagoras [550 BC] to the Christian Scholastics [1100-1400 AD]; no one believed the Earth was flat:

“Pythagoreans believed that the earth was a globe floating freely in space because the sphere was the perfect shape.”

“Aristotle invoked the proof of ships disappearing over the horizon, hull before masts, along with the earth’s circular shadow on the moon during a lunar eclipse and the different appearance of stars when viewed from different latitudes, to support the contention that the earth was a globe in his book On the Heavens.”

“Greek writers, from Plato to Eudoxus (c. 375 BC), Euclid (c. 300 BC), Aristarchus (c. 310–230 BC) and Archimedes (287–212 BC), accepted a globular earth, while Aristotle’s geocentric cosmology – centring on an immobile sphere at the centre of the universe with the planets moving around it in perfect concentric circles – was to dominate Western cosmological thinking until the work of Copernicus and Galileo nineteen centuries later.”

“popular Roman writers Pliny the Elder (c. 79), Macrobius (c. 400), Martianus Capella (c. 420) and Boethius (c. 480–524), all of whom helped the Ptolemaic view of a spherical earth to survive in the Christian West without any input from the Islamic world.”

Christian belief was vital in the development of civilization, and so central to its creation, that there is no modern world without it:

“Christianity had a critical role in preserving and spreading the scientific knowledge that had survived from Greco-Roman times. Of particular importance was the study of the quadrivium, the study of four liberal arts – arithmetic, geometry, astronomy and music (often accompanied by medicine) – which took place in monastic and cathedral schools between the fifth and twelfth centuries and further disseminated knowledge of the spherical shape of the earth.”

Science is never settled. Even extremely smart Catholics such as Kepler and Copernicus had no idea about the real distance from the Earth to the Sun [90 million miles]:

“...earth’s distance from the sun, for example, Copernicus computed it as 3,391,200 miles, Kepler contradicted him with an estimate of 12,376,800 miles, while Newton had asserted that it did not matter whether it was 28 million or 54 million miles ‘for either would do well’.”

Copernicus was off by 97% [the usual percentage given for scientific 'consensus']. I doubt that many today would call him a quack. In any event Christians were central to the innovations in all areas of science. Stating otherwise only shows the ignorance of the speaker.