Indeed, you can't know what you know until you know it, and you can't know the value of knowledge until perhaps decades or centuries after it was originally acquired. Thus the logical choice is to be quite promiscuous in the acquisition of knowledge and to maintain a healthy degree of curiosity towards all manner of knowledge, no matter how seemingly abstract or useless.
The study of electromagnetism and quantum mechanics in the 19th and early 20th centuries has resulted in an economic benefit somewhere in the range of quadrillions of dollars of value, and hundreds of billions of person-years of life/lives added which would not have been possible otherwise. And all from some nerds futzing around with things they thought were interesting.
I think that sort of RoI justifies spending a few billion here and there now and again on seemingly esoteric research.
Case in point: think about lasers. They were described as interesting but totally useless phenomena when first developed in the 50s/60s. They were called a "solution looking for a problem". Look where are we now with them, just 50 years later.
The study of electromagnetism and quantum mechanics in the 19th and early 20th centuries has resulted in an economic benefit somewhere in the range of quadrillions of dollars of value, and hundreds of billions of person-years of life/lives added which would not have been possible otherwise. And all from some nerds futzing around with things they thought were interesting.
I think that sort of RoI justifies spending a few billion here and there now and again on seemingly esoteric research.