(Michael Vassar has an extended thesis on how the scientific community in our Earth has been slowly dying since 1910 or so, but I'll let him decide whether it's worth his time to write up that post.)

I put the inflection point near 1970 instead, and a variety of reasons support this:

• Disappearance of merit scholarships to elite universities in America

• Explosion of the cost of attending elite universities in America

• Explosion of income of doctors and lawyers, without any explosion of income for scientists and engineers

• Leveling off of the US science budget, which had grown exponentially until about 1970

• Leveling off of the number of scientists trained in the US, which grew exponentially until about 1970

• Rise of semiconductor-related industries, which had huge commercial returns and have absorbed most commercial research investment money since then (resulting in lower return on investment for research because you need exponentially-increasing funds to get constant output in terms of important discoveries within a single field)

• Project Hindsight concludes that basic research is a waste of money

• US enters a prolonged period of cultural economic irresponsibility

• NASA diverts a high percentage of US brains and research dollars into research with a very low discovery/cost ratio

• Government regulations on business and research rise dramatically in the 1960s, e.g., FDA regulation goes from specifically naming drugs to be regulated, to requiring all drugs to prove safety and efficacy

But you might be able to come up with just as good a list for some other decade, if you tried.