The discussion revolves around whether the gravitational field of Earth strengthens upon receiving light from the Sun, specifically focusing on the implications of photons and their energy in relation to gravitational fields. The scope includes conceptual and theoretical considerations regarding gravity, mass, and energy in the context of relativity.
Participants express disagreement regarding the role of photons in contributing to Earth's gravitational field. While some assert that photons cannot contribute due to their lack of mass, others explore the idea that energy can influence gravitational fields. The discussion remains unresolved with multiple competing views.
Participants note the assumptions regarding mass, energy, and the nature of gravitational fields, as well as the implications of thermal equilibrium on the discussion of gravitational effects from incoming light.
D H said:
You don't need mass , to create a gravitational field , In relativity mass or energy bends space time , and if the field associated with the photon goes away where does the field go or the energy , doesn't the energy from the photon still create a field .clustro said:DH... did you post in the right thread?
And cragar: I am pretty sure to have a gravitational field, you need mass. Photons don't have mass, so they don't have the field, and therefore can't contribute to Earth's gravity field.
of course, even if they had mass, you have to assume that all photons impinging upon the Earth actually stay on the earth, leading to a buildup of mass.
Seems weird, no?
clustro said:
The Earth is in thermal equilibrium. The incoming solar radiation is balanced by outgoing radiation, mostly thermal. Think of the Earth as an energy-neutral frequency converter.
Photons carry energy. Energy, like mass, curves space-time. (Mass is energy.)