A common question in physics is whether a human body generates its own gravitational field, and the scientific answer is yes. Gravity is a fundamental force described as the attraction between any two objects that possess mass. Since every person has mass, they inherently exert a gravitational pull on everything else in the universe. This phenomenon applies equally to a person, a grain of sand, or a distant star.
Universal Law of Gravitation
The exact magnitude of this universal force is described by Isaac Newton’s law of gravitation. This law states that the force of attraction is directly proportional to the product of the two masses involved. If either mass doubles, the gravitational force between them also doubles. The law also includes an inverse square relationship with distance, meaning the force drops off rapidly as the distance between objects increases.
The formula requires a proportionality factor known as the gravitational constant, or “Big G,” which is a fixed value used in all gravitational calculations. This constant is approximately 6.674 x 10^-11 Newton meters squared per kilogram squared. The extremely small value of Big G is the reason why gravity is such a weak force in everyday experience. Only objects with masses on the astronomical scale, such as planets or stars, can generate a gravitational field strong enough to be easily observed.
Quantifying the Force
To put the human gravitational pull into perspective, consider the force of attraction between two average-sized people. If two people, each weighing about 150 pounds (68 kilograms), stand one meter apart, the gravitational force between them is minute. Calculating this attraction using Newton’s formula yields a force of roughly 3 x 10^-7 Newtons.
This tiny magnitude is equivalent to the weight of a microscopic dust particle or a single small bacterium. This attraction is billions of times weaker than the electromagnetic forces that hold atoms together. Even the gentle force from a light breeze is vastly greater than this gravitational pull. The slightest tremor or vibration in the floor would easily overwhelm this minuscule attraction.
Overwhelmed by Earth’s Gravity
While the gravitational pull between two people is real, it is completely imperceptible in daily life because of the massive influence of the Earth. The planet’s gravitational force is the overwhelming factor that dictates all movement and stability on its surface. When a 150-pound person stands on the ground, the force of Earth’s gravity pulling them down is approximately 667 Newtons.
Comparing the 3 x 10^-7 Newtons of person-to-person attraction with the 667 Newtons of person-to-Earth attraction reveals the dominance of the planet. This difference means the Earth’s pull is more than two billion times stronger than the mutual pull of two nearby humans. The Earth’s immense mass, nearly 6 x 10^24 kilograms, creates a gravitational field that completely overshadows the tiny forces generated by human bodies.