While it is possible for great scientists or scholars to continue making significant contributions to their fields in their later years, the ability to create entirely new fundamental theories and concepts may become more challenging as they age. However, it's important to note that every individual is unique, and there can be exceptions to general trends.
Advancing scientific knowledge often requires a combination of creativity, mental agility, and the ability to assimilate and integrate complex information. As individuals age, cognitive abilities may naturally decline, and they may face challenges in processing and integrating new information. Additionally, the scientific landscape and research methodologies may have evolved, requiring familiarity with new technologies and approaches.
That being said, there have been instances of eminent scientists and scholars making significant contributions in their later years. For example, Paul Dirac, a renowned physicist and one of the founders of quantum mechanics, made substantial breakthroughs in his research in his 70s. Similarly, Vera Rubin, an astrophysicist, made pioneering discoveries in her field well into her later years.
As for whether Einstein could have produced his concept of relativity at the age of 75, it's difficult to say with certainty. Einstein's development of the theory of relativity occurred when he was in his early 30s. While it's possible for an individual to continue making important contributions later in life, it is less common to develop entirely new fundamental theories at such an advanced age.
Nevertheless, it's important to recognize that scientific progress is a cumulative effort that builds upon previous discoveries. Even if a scientist does not create entirely new fundamental theories in their later years, they can still make valuable contributions by refining existing theories, providing insights, mentoring younger researchers, and synthesizing knowledge from their extensive experience.
Ultimately, while age can present certain challenges to creating groundbreaking theories, the potential for intellectual growth and contributions to science persists throughout a lifetime, albeit in different forms.