The reason the Earth hasn't fallen into the Sun is due to its orbital motion and the balance between gravitational attraction and centrifugal force.
The Earth is in a state of constant freefall toward the Sun, but its forward motion keeps it in a stable orbit. This motion is a result of the gravitational pull of the Sun and the initial velocity of the Earth. The Earth's velocity is directed tangentially to its orbit, creating a balance between the inward pull of gravity and the outward force generated by its motion.
This balance is governed by Newton's laws of motion and the law of universal gravitation. The gravitational force between the Earth and the Sun depends on the masses of the two objects and the distance between them. The Earth's mass is relatively small compared to the Sun, but its distance from the Sun allows for a stable orbit.
In essence, the Earth is constantly falling toward the Sun but keeps missing it because of its forward velocity. This motion creates an orbit that follows an elliptical path around the Sun. The Sun's gravity continually pulls the Earth inward, while the Earth's velocity prevents it from falling directly into the Sun.
It's worth noting that the Earth's orbit is not perfectly circular but slightly elliptical, which means its distance from the Sun varies slightly throughout the year. However, this doesn't affect the overall stability of the orbit.
In summary, the combination of the Earth's gravitational attraction to the Sun and its forward velocity creates a balanced orbit, preventing the Earth from falling into the Sun.