THE GENERAL THEORY OF RELATIVITY

The general theory of relativity derives its origin from the need to extend the new space and time concepts of the special theory of relativity from the domain of electric and magnetic phenomena to all of physics and, particularly, to the theory of gravitation. As space and time relations underlie all physical phenomena, it is conceptually intolerable to have to use mutually contradictory notions of space and time in dealing with different kind of interactions, particularly in view of the fact that the same particles may interact with each other in several different ways-electromagnetically, gravitationally, and by way of so-called nuclear forces.

Newton's explanation of gravitational

THE GENERAL THEORY OF RELATIVITY

The general theory of relativity derives its origin from the need to extend the new space and time concepts of the special theory of relativity from the domain of electric and magnetic phenomena to all of physics and, particularly, to the theory of gravitation. As space and time relations underlie all physical phenomena, it is conceptually intolerable to have to use mutually contradictory notions of space and time in dealing with different kind of interactions, particularly in view of the fact that the same particles may interact with each other in several different ways-electromagnetically, gravitationally, and by way of so-called nuclear forces.

HEAT TRANSFER

 Heat can be transferred by three processes: conduction, convection, and radiation. Conduction is the transfer of heat through a solid object; it is this process that makes the handle of a poker hot, even if only the tip is in the fire. Convection transfers heat through the exchange of hot and cold molecules; this is the process through which water in the kettle becomes uniformly hot even though only the bottom