Aristarchus of Samos theorized in the third century BCE that the Sun, not the Earth, was the center of the solar system. It took 17 centuries for Nicolaus Copernicus to arrive at the same conclusion.
In the first century AD, Heron of Alexandria developed what has been called the world’s first steam engine, which he described in his Pneumatica. The Aeolipile was a metal sphere with two bent rods placed on an axle that brought steam into the sphere. The steam coming out of the bent rods caused the sphere to turn. In his day this device was used only for entertainment. Again, it took 17 centuries for others to transform the principle underlying this novelty into the industrial steam engine that changed the world.
The Mesoamericans who lived in North and South America before the arrival of Europeans had discovered the wheel but used it only in their children’s toys.
In the first half of the 19th century, Charles Babbage designed a kind of mechanical computer that later came to be called the Analytical Engine. He was not much of an organizer and failed to build the engine during his lifetime. It was not until the 1990s that a team built a machine according to his design and found that it worked. It is possible that the age of the computer would have begun a century earlier if Babbage had built his machine during his lifetime. The weaker example of the Antikythera Mechanism, an orrery and the world’s oldest analog computer dated to the second century BCE, and similar machines from antiquity provoke related questions.
These are all missed trains of history. Had these connections been made earlier by someone perceptive enough to have a certain thought at a certain time, the expeditions into the lightless caverns of our collective ignorance would have covered more ground than they have up to today. The aggregate of human knowledge would be vastly deeper and wider than it is. Progress is not as simple as we would like to believe but I think that more knowledge is better than less in almost every case. This fact alone should light a fire of urgency and energy under us in our pursuits. Who knows what connection is waiting to be found on the next page or in the next investigation?
 Direct.mit.edu/posc/article/24/3/264/41548/The-Aeolipile-as-Experimental-Model-in-Early, May-June 2016.
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 Johnrhudson.me.uk/computing/Menabrea_Sketch.pdf, 1843.
 Computerhistory.org/babbage, accessed October 15, 2021.
 Nature.com/articles/nature05357, November 1, 2006.