The work that led to our understanding of why objects fall to Earth instead of floating into space is attributed to Sir Isaac Newton and his groundbreaking work "Philosophiæ Naturalis Principia Mathematica" (Mathematical Principles of Natural Philosophy), published in 1687.

Here's why:

* Universal Gravitation: Newton's Principia introduced the concept of universal gravitation, which states that every object in the universe attracts every other object with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

* Earth's Gravity: This universal attraction applies to the Earth and everything on it. The Earth's massive size and density create a strong gravitational pull that attracts all objects towards its center, causing them to fall.

* Orbital Motion: Newton also explained that objects don't necessarily fall straight to Earth. If they have enough horizontal velocity, they can enter orbit around the Earth, continuously falling but never hitting the ground.

While earlier thinkers like Galileo Galilei had made important observations and contributions regarding falling objects, Newton's work provided a comprehensive mathematical framework for understanding gravity and its effects, ultimately explaining why things fall to Earth.