YES: Various processes, branches and specializations of modern science are increasingly speculative rather than empirical, making it unreliable to human knowledge and experience.
Some radical branches of science, such as string theory, aim to provide an overarching theory or framework to represent the totality of reality and human experience, and are presently speculative rather than conclusive in their findings.
Specialized branches of medical science, such as psychiatry, incorporate theories on human behavior and social practices that are highly context specific rather than replicable in nature, making their practice less predictable or reliable than other forms of science.
Science may occasionally stretch the boundaries of human experience, knowledge and credulity by venturing into highly theoretical constructs, such as time travel and fourth dimensional spaces, that our present levels of technology cannot meaningfully prove or support.
NO: Many processes, branches and specializations of science are based on empirical findings and outcomes, thereby reaffirming its reliability and centrality to human knowledge and experience.
The more established branches of science are built upon the empirical research and findings of previous generations of scientists, providing many reliable theories and practical applications of knowledge to multiple aspects of human life and endeavors.
Contrary to popular misconceptions, specialized branches of medical science, such as the inherited behavioral traits of twins, incorporate theories on human behavior and social practices only after extensive trials and research into their veracity, replicability and relevance to medical practice.
With time and developments in technology, previously theoretical constructs, such as stealth technology, have been proven or supported substantively, making science an empirical rather than abstract discipline.