"celestial mechanics, in the broadest sense, the application of classical mechanics to the motion of celestial bodies acted on by any of several types of forces."
https://www.britannica.com/science/celestial-mechanics-physics
"Physicist Michio Kaku doesn't entirely rule this possibility out, but he cautions that powering a time machine to travel in this way is beyond human capabilities right now, and would demand either negative energy or the energy of a star"
https://futurism.com/how-much-energy-need-power-time-machine
"kinetic energy, form of energy that an object or a particle has by reason of its motion. If work, which transfers energy, is done on an object by applying a net force, the object speeds up and thereby gains kinetic energy. Kinetic energy is a property of a moving object or particle and depends not only on its motion but also on its mass. The kind of motion may be translation (or motion along a path from one place to another), rotation about an axis, vibration, or any combination of motions."
https://www.britannica.com/science/kinetic-energy
"Potential energy is an energy, which exists because of the mutual interaction between two or more systems. The energy possessed by the body or system due to its position or configuration, or arrangement is called potential energy."
https://lambdageeks.com/is-potential-energy-stored-energy/
"Energy can be in many forms! Here we look at Potential Energy (PE) and Kinetic Energy (KE)."
https://www.mathsisfun.com/physics/energy-potential-kinetic.html