Energetics

The scientific study of Energy, primarily how to transfer move energy and change energy states.

The main job of energetics is to produce useful energy for automating processes that would normally require human labor.

Sources

Energy comes in a lot of forms. The two main theoretical forms are potential energy (stored energy) and kinetic energy (moving energy).

Kinetic energy more formally is a form of energy that an object or a particle has by reason of its motion. 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.

Potential energy more formally is stored energy that depends upon the relative position of various parts of a system. A spring has more potential energy when it is compressed or stretched. A steel ball has more potential energy raised above the ground than it has after falling to Earth. In the raised position it is capable of doing more work. Potential energy is a property of a system and not of an individual body or particle; the system composed of Earth and the raised ball, for example, has more potential energy as the two are farther separated.

These two types of energy can be transformed into each other. A good example is if you raise an object up, you give it potential energy. The more you raise it, the more energy you give it. If you release it, it loses potential energy the closer it gets to the ground, but it gains kinetic energy as it picks up speed and slams into the earth.

Perhaps one of the most immediately useful sources is water. When you have flowing water, like a river or waterfall, you can use some of that kinetic energy to move other things.

The primary way to do this is by something called a water wheel. This can be constructed out of any material but usually it is made out of wood. A water wheel is a large wheel that has buckets attached so that the moving water source catches the buckets and turns the wheel. The resulting energy from the spinning wheel can be used to rotate a shaft which can transfer the moving energy anywhere you want. This rotating energy is usually used for massive turning operations. Some of these operations may include grinding grains into flour, turning a spit that has food on it so that the food gets cooked well all around, even turning large machines like textile machines. This spinning motion can also generate electricity. Electricity is perhaps the most useful form of energy that humans have discovered so far because it can travel really far and fast without losing energy.

Since spinning an axel is the best form of generating energy, here are several ways to do it.

Water wheel

The water wheel is perhaps the best device to start off with. It can easily be built as a wheel with buckets attached. This wheel can spin the axel attached to its center and the spinning axel can transfer the energy.

Heat

Once you find coal, you can use this or other heat sources to create steam with water. The steam can be directed to move in an upwards direction where there can be a fan. The steam will attempt to push upwards through the fan thus rotating the fan. This is the basics of a steam engine. Heat can also be generated using radioactive elements. This is the basics of a nuclear reactor.

Gasoline

Assuming there is actually an earth left still, you should be able to scrounge around for leftover parts. You should be able to find cars and other heavy equipment that has an engine in it. This is powered by an oil byproduct called gasoline.