Why do fields exist around mass and charge?

Fields exist around mass and charge because they exert forces that influence other masses and charges in their vicinity.

In physics, a field is a region in space where a mass or charge experiences a force. The concept of a field is used to explain how forces can act at a distance, without any physical contact. Fields are a fundamental concept in physics, and they are used to describe the forces between charged particles (electric fields), between masses (gravitational fields), and between magnets (magnetic fields).

The existence of fields around mass and charge can be understood by considering the effects they have on other masses and charges. For example, if you place a small test charge in the vicinity of a larger charge, the test charge will experience a force due to the electric field of the larger charge. Similarly, if you place a small test mass in the vicinity of a larger mass, the test mass will experience a force due to the gravitational field of the larger mass. This is how we know that fields exist: we can observe their effects on test charges and test masses.

The concept of a field is a way of describing how a mass or charge 'reaches out' and affects other masses or charges. It's a bit like the way the sun's light reaches out and illuminates objects in the solar system. Just as the sun's light is a form of energy that travels through space, a field is a form of energy that exists in space around a mass or charge. The strength of the field decreases with distance from the mass or charge, just as the intensity of the sun's light decreases with distance from the sun.

In summary, fields exist around mass and charge because they exert forces that influence other masses and charges in their vicinity. The concept of a field is a fundamental part of our understanding of the physical world, and it is used to explain a wide range of phenomena, from the forces between charged particles to the gravitational attraction between planets.