This question is similar to What was the longest delay between prediction and confirmation of a theory? but I want to frame it in a different way. I am looking for long delays between prediction and discovery, that were predicted under the frame of the current theory. Here are some examples of what I mean by this:
Examples that fit the description:
- Einstein prediction of gravitational waves in 1916 and discovery by LIGO in 2015. Many people suggested it before like Heaviside or Poincaré but under complete different classical theories.
- Prediction of the Higgs boson 1964, discovery in 2012. Predicted under a new theory but clearly the right one as it is the current one in the Standard Model.
- Prediction of planets. For example Neptune was predicted in 1846 using Newtonian mechanics, and found short after.
Examples that do not fit the description: Based on the previous question, here are some examples based on that question that are not what I am looking for
- Atomism by Democritus in Ancient Greece and confirmed definitively in 1905. Clearly a good guess, but science had to break so many paradigms that his predictions have more to do with philosophy than science. Dalton is also not that great because chemistry models were to be refined many times after him (also quantum mechanics was weirder than anything imagined).
- John Michell's prediction of black holes in 1783. Again a good guess based on classical mechanics but general relativity is more clearly suited.
- Heliocentrism, it is not truly a prediction, it is more like we have data, we have two models, which is it?
So are there any predictions under the theory of the time or closely-suggested theory that took as long or more than the time between the prediction and detection of gravitational waves?