Defining an “Earliest-Time” tag

Question

From time to time we encounter questions of the form:

What is the earliest time X could be discovered or built?

Examples include:

• What is the earliest time a pulsejet could be built?
• How early can transparent glass windows be easily available?
• How early can nuclear reactors be built?
• Earliest Possible Gun?
• What is the earliest that a civilization could develop airships?

These are fun questions because they ask us to look backward with 20/20 hindsight and consider what shifts in history would have permitted an earlier discovery. In this regard, they are alternate-history questions.

They're also prone to being primarily opinion-based due to the scope of the problem. Any one aspect of technology stands atop a mountain of experience, education, and innovation that has been influenced heavily by societal developments including philosophy/religion and government, as well as resource availability. The development of any technology or scientific discovery is quite complex and determining how much of that mountain need not have existed to permit earlier discovery is a challenge.

Because the question type is relatively unique and represents a quality challenge for Worldbuilders, I would like to create an earliest-time tag that defines the nature of this question, warns of its weaknesses (to avoid closure), and helps guide the development of good questions with (hopefully) a modicum of research.

Question: what guidance should we give to users of this tag? (Alternatively, "what's the best way to ask this type of question?")

Answer 1

Be specific about the tech you're interested in.

The more ambiguous your technology or scientific development reference, the more likely your question will be closed. For example, consider the question, "how early could steam tech be invented?" Here's the problem:

• The Aeolipile was invented 2,000 years ago.
• The first commercially-successful steam engine (an engine, not a locomotive) was the Newcomen atmospheric engine in 1712.
• The first full-scale steam locomotive was the Coalbrookdale Locomotive built by Richard Trevithick in 1804.
• The Age of Steam was a period of steam-powered industrialization between 1770 and 1914.
• Steam turbines used everywhere from military naval vessels to electric power generation are still manufactured and in use today.

And that's a short list of major advancements. There are hundreds (if not thousands) of individual technologies that fall within "steam technology." As you can imagine, moving the Aeolipile back 100 years is a very different question compared to moving the development of the Pacific class 4-6-2 steam locomotive back 100 years.

Unless your question addresses a specific technology, answers may span thousands, hundreds, and tens of years and refer to everything from bronze or brass metallurgy to industrialized manufacturing to laser-guided milling; making the question primarily opinion-based.

Answer 2

Attempt to "discover something early" as late as possible.

The further back you wish to push the development or discovery of a technology, the less likely it can be achieved. Every advancement stands atop a mountain of experience, education, and innovation. Each of those are dependent on social status, government type, philosophical and religious influence, resource availability, and communication. The resulting interdependence of any one technology on a vast web of necessary conditions is considerable (and often difficult to define).

Consequently, the less time needed for the push-back, the simpler it is to justify whether it is possible to do so. It's worth noting that 99% of the technology we enjoy today was invented in the last 150 years — which suggests pulling any modern advancement back another 150 years is very difficult, and pulling it back earlier is next to impossible.

Therefore, if you only need to develop a specific technology 20 years earlier, please do not ask for 100.

Answer 3

Clearly outline any timeline or resource modifications (limitations & enhancements)

Occam's Razor is a problem-solving philosophy that can be simply (and popularly) expressed as, "all things being equal, the simplest answer is usually correct." If we apply Occam's Razor to the question, "how early could technology X have been discovered?" then, all things being equal, the answer is, "not one moment before it was discovered."

This is due to the natural complexity of advancement, although it ignores the possibility of epiphany. But, epiphany could only advance anything by, perhaps, days or weeks. All of the thought, experimentation, innovation, hypothecation, and experience that came before any specific advancement must logically be required for that advancement.

But, what if there were some change in history that could affect that advancement? Often, the user asking the "how early" question is seeking that change in history, which is the most difficult way to ask the question. They're seeking that quirk of plot that rationalizes the story they want to tell.

It is better if that quirk comes first. Does your plot have the technology for gun powder find its way out of China centuries before it did? That would advance firearm development considerably! What if the bauxite deposits of Virginia (U.S.A.) were discovered in the 1790s rather than in 1915 when they were actually discovered? How would that affect the development of aluminum and, thereby, naval technology during the 1800s? What if coal was scarce in England? How would that have affected the development of Steam and, thereby, the Industrial Revolution?

If possible, the OP should explain any limitations or enhancements to the technology tree that would affect the question. Failure to supply limitations or enhancements may cause questions to be closed as Too Broad.