Final answer:
Albert Einstein proposed that gravity is the bending of space-time due to the presence of matter, an idea which is central to the theory of general relativity.
The concept was first confirmed by the bending of starlight observed during the 1919 solar eclipse.
Step-by-step explanation:
The person who first proposed that gravity is the bending of space-time due to the presence of matter was Albert Einstein.
His groundbreaking work laid the foundation for the general theory of relativity, which transformed our understanding of gravity, space, and time. Einstein's theory postulated that the presence of matter distorts the fabric of spacetime, and this curvature is what is perceived as gravity.
Einstein's insights were affirmed when observations during a solar eclipse in 1919 revealed the bending of starlight near the Sun, which matched his predictions and thereby provided the first verification of general relativity.
This observation indicated that not just physical objects, but even light itself, must follow the curvature of spacetime created by mass.
Einstein's revolutionary theory has since passed numerous tests and remains a cornerstone of modern physics.