No matter how convinced we are that X is true, there is always the possibility that it is not, because we have been ignorant of, overlooked, misinterpreted, or misunderstood something. From The Correction Heard 'Round The World: When The New York Times Apologized to Robert Goddard by Kiona N. Smith.
Fifty years before Neil Armstrong, Buzz Aldrin, and Michael Collins climbed into their small capsule to fly to the Moon, many people weren't even convinced that rockets would work in space. When a rocket engine ignites, it burns fuel and pushes exhaust out the back end of the rocket with tremendous force. According to Isaac Newton's Third Law of Motion, every action produces an equal and opposite reaction -- which means the backward thrust of the rocket's exhaust also acts on the rocket, pushing it forward. Many people, including the author of a January 13, 1920 editorial in the New York Times, misunderstood Newton's law and assumed that rockets worked because their exhaust pushed against the air itself. With no air to push against, how could a rocket actually push itself through space?The New York Times, however, never regrets its errors enough to actually display humility when dealing with complex science, especially if they have an ideological dog in the fight. Witness their multi-decade commitment to anthropogenic global climate warming. An ideological fig leaf for authoritarian action based on skimpy data and an incomplete understanding of multiple loosely coupled complex dynamic systems, none of which are fully understood.
Today, we know that Newton's Third Law means that rocket engines don't need air to "push against," but in the early days of January 1920, Goddard faced instant skepticism when he published an article in Popular Science describing how rockets could launch ships into space. It was an ambituous piece of work, and Goddard even outlined an uncrewed Moon mission, in which a rocket carrying an explosive payload would crash into the Moon, producing an explosion so large that scientists could see it from Earth. Goddard was ahead of his time in some ways: NASA and other space agencies have crashed quite a few objects into various Solar System bodies, because slamming a heavy, fast-moving object into a planet turns out to be a great way to learn something about what it's made of.
Although the article caught the public imagination, it also drew harsh criticism. Various outlets argued that the velocity required to escape Earth's gravity would produce so much friction that the rocket wouldn't survive the heat (rockets accelerate gradually, so by the time they reach escape velocity, they're in the thin upper layers of the atmosphere), that payloads would never survive re-entry into Earth's atmosphere (engineers worked that problem, and Goddard himself proposed an ablative heat shield to protect returning spacecraft from the heat of re-entry), or that there was no scientific or social reason to shoot things into space (shortsightedness is not a new phenomenon). Others argued that it would be impossible to make all the calculations required to account for high-altitude winds and the complex relative motion of Earth and the Moon. Fortunately, the Apollo program had Katherine Jonson, Dorothy Vaughan, Mary Jackson and other "computers" to make that happen, but it's easy to see how daunting the prospect would have been in 1920.
And on January 13, 1920, the New York Times published an editorial insisting that a rocket couldn't possibly work in space:
"That professor Goddard, with his 'chair' in Clark College and the countenancing of the Smithsonian Institution [from which Goddard held a grant to research rocket flight], does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react -- to say that would be absurd. Of course he only seems to lack the knowledge ladled out daily in high schools."[snip]
Eventually, of course, Goddard would be vindicated by the 1944 launch of a German V-2 guided ballistic missile. But it took until July 17, 1969, the day after the launch of a crewed mission to the Moon, for the New York Times to take back its harsh words. The 1969 correction is almost comically dry and conspicuously doesn't mention the Apollo mission.
"Further investigation and experimentation have confirmed the findings of Isaac Newton in the 17th century, and it is now definitely established that a rocket can function in a vacuum as well as in an atmosphere," the Times editors wrote. They added, "The Times regrets the error."
AGCW has virtually disappeared from the lexicon, first replaced by climate warming, and then, as that failed to appear in the data, replaced yet again by the virtually meaningless climate change. Given that climate is always changing and that virtually no one claims otherwise, the hunger for imposing ideological solutions remains, even as the evidence for the problem disappears.
Goddard had to wait 49 years for an apology. Perhaps all the "deniers" (as mischaracterization if ever there was one) will get an apology circa 2039.