1. Albert Einstein is the physicist credited with proposing the revolutionary concept that space and time are not independent entities but are intertwined into a single fabric of spacetime.
   
2. This idea is a cornerstone of his Theory of General Relativity.
   
3. While there isn’t a single, exact quote that encapsulates this concept, Einstein’s writings often emphasized the interconnectedness of space and time.
   
4. Here’s a passage from his popular science book, “The Meaning of Relativity,” that conveys the essence of his idea:
   

The fundamental idea of the theory of relativity is that space and time are not independent entities, but are aspects of a single entity called spacetime. The laws of physics are the same in all inertial frames of reference. This principle, combined with the assumption that the speed of light is constant in all inertial frames, leads to the conclusion that space and time must be interconnected in a way that is different from our classical intuition.

5. This passage highlights Einstein’s groundbreaking realization that space and time are not separate entities but are intertwined and influenced by each other. The concept of spacetime has become a fundamental pillar of modern physics.
   

1. The physicist who first introduced the idea that space and time would no longer exist as independent entities but would instead be unified into spacetime is Albert Einstein.
   
2. He introduced this concept as part of his theory of special relativity in 1905 and then expanded upon it with his theory of general relativity in 1915.
   
3. One famous physicist who summarized this concept clearly was Hermann Minkowski, Einstein’s former professor.
   
4. In 1908, Minkowski gave a lecture in which he introduced the notion of spacetime. He said:
   

Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.

5. This quote is from his lecture “Space and Time,” delivered in 1908, which laid the groundwork for thinking of space and time as a unified four-dimensional spacetime continuum.
   

1. My question at StackExchange History of Science and Mathematics