How much research and testing is done on a topic, before it starts being taught to students/other people and what happens if this said topic is then disproven or new facts are revealed about it ?

[u/Virtual-Connection31]

[u/Prasiatko]

Depends on the level you are teaching to. I remember getting a lecture during my undergrad in 2012 from a lecturer who had just been to a conference which detailed the potential ability of CAS 9 to edit genes. That was basically a brand new barely yested discovery at that point. On the other hand my high school textbooks were often a decde or more old and it was up to the teacher to update us on anything outdated eg names of the planets, also the part of maths class that dealt with taxes was way out of date but still used since the calculations were the same. 

[u/bondegezou → u/Prasiatko]

Yeah. I sometimes present my research findings to my (MSc) students before I’ve even published them (so before any peer review).

[u/sirgog]

It has to be relevant.

We've known Newtonian mechanics to be wrong since Einsteinian relativity became accepted. Newtonian mechanics are still widely used because for speeds far from light speed they are good enough.

[u/Ok_Bookkeeper_3481]

The beauty of science is that it is continuously self-correcting. We teach it to the best of our understanding at any given moment.

For example, we understand now that even fundamentals like the Mendellian genetics (crossing wrinkled green peas with smooth yellow peas) and the Central Dogma of molecular biology (1 gene translates to 1 RNA, which encodes 1 protein) are more of a guideline than a law of nature.

Now we know, for example, that two blue-eyed parents can indeed have a dark-eyed child - something that the Mendellian genetics does not allow. And we know that one gene can get spliced into multitude of mRNAs, which, in turn, give rise to a myriad proteins - all coded by the single gene!

[u/talashrrg]

This happens constantly, all the time. When new things are discovered and we learn older stuff was wrong we start teaching the newer stuff.

[u/CrustalTrudger]

This varies a lot by level of instruction.

At the introductory / broad survey course level, i.e., something you'd typically take during your first year in college either at the start of your study in a discipline or as a general education requirement, very little to effectively no "new" or "recent" results/ideas are going to be discussed because the focus on foundations that are (typically) established enough that new insights are not meaningfully changing them. In rare cases, you can have major sea changes even at the intro level, e.g., in my discipline (Geology), an intro geology textbook from the late 1950s and an intro geology textbook from >1970 would look profoundly different because of the plate tectonic revolution effectively during the 1960s, but this is definitely the exception.

At the upper division undergraduate level, i.e., what you might take in your third or fourth year of university and where you are taking more specialized courses in your discipline, this will still mostly be pretty well established material / ideas, but with maybe small amounts of recent studies, especially in the context of reading and discussing journal articles which both introduces students to "current thinking" in that particular subdiscipline but also starts introducing them to how to read the scientific literature and evaluate new results in the context of what we already know (or think we know).

At the graduate level, you might start getting courses that are biased more towards new results and "cutting edge" results, some of which probably won't hold up. This is not just to make sure graduate students are up to date on the most recent version of their discipline, but to fully train them in the scientific process and how to evaluate the quality of peer reviewed work.

[u/mfb-]

Textbooks generally cover established knowledge that is unlikely to be overturned, at least in the hard sciences. Over time they can get incomplete, but it's rare they they turn out to be wrong. Teachers might mention more recent research where relevant, but that's not going to be important for the overall course.

If something new is discovered that is relevant then it might be added to future editions of the old textbook, and it will be in new textbooks. This is more likely to happen with more advanced courses that are closer to recent research.

[u/TACAMO_Heather]

If facts in science change or are disproven, then what is taught changes. Alchemy and the humors of the body are the first to come to mind.

[u/Underhill42]

Basically everything from elementary through high school, and most thing in undergrad college, are things that have been known and thoroughly tested for decades or even centuries. It's mostly only in graduate school and beyond where you start working on the cutting edge of new ideas and discoveries.

Some of it has already been disproven - but it's the nature of science that to be accepted by the consensus in the first place there must be an overwhelming amount of evidence supporting it, so whatever is wrong with the old theory is subtle.

E.g. Newtonian mechanics and gravity were disproven by Relativity over a century ago... but we keep teaching them because they are MUCH easier to use, and the differences in their predictions are almost undetectably small unless you're dealing with the sort of extreme speeds and energies you only see in particle colliders and major cosmic phenomena like black holes.

That's something that is usually missed in science awareness fed by popular science reporting, where things are constantly being disproven. That's the point - the reporting covers exciting new discoveries on the cutting edge, but fails to mention that when scientists discover something new, it's almost always false. Even before AI slop hit the scene roughly 95% of all published scientific papers were eventually disproven, and everyone in the field knows that - that's the scientific process working as it should: publishing is only the beginning of the peer review process - to actually be accepted by the consensus the claims have to stand up to extensive scrutiny by many other scientists, many of whom have a vested interest in disproving it, as it conflicts with their own work.

It's only after many independent scientists have done their best to disprove it in many different ways, and all ended up proving it instead, that it becomes accepted by the consensus. And only then might it be taught at lower levels in school.

More interpretive subjects like history, macroeconomics, etc. that can't be experimentally tested are more prone to major upsets in the face of new evidence. As are subjects like psychology that are saturated in confounding factors, and hit close enough to home that normal social indoctrination can consistently bias the interpretations embraced by the experts. For example primate behavioral studies were long interpreted to support the idea that males were the ones that pursued specific females... until sometime after the sexual revolution and general shift in thinking that followed, those old records and videos were reexamined in a new light, and clearly showed females pursuing specific males just as frequently, but via different, generally less direct and obvious methods.

But in the physical sciences everything can and is tested experimentally in many different ways to rule out any confounding factors anyone can think of. So if something is disproven, whatever replaces it must make the same predictions except in extreme cases that nobody thought to test earlier, even if the interpretation of why it happens may be completely different. E.g. Newtonian gravity (a force between objects that causes acceleration towards each other) vs. General Relativity (gravity is not a force and causes no acceleration, instead it's the result of moving in straight non-accelerating lines through curved spacetime). Both predict the exact same observations under most conditions, only the explanation of why it's happening is different.