What Is Energy?

Energy may be best understood as a potential or presence that allows for some type of work to be performed. Some of energy’s more recognizable forms are heat, light, mechanical, chemical, and electrical energy. Without energy we simply would not exist. The universe, if it existed at all, would be a frigid, barren, motionless void.

Energy is neither created nor destroyed, however it can be converted from one form to another. This means that while the total amount of energy in the universe remains constant, the quantity of the different forms can change relative to one another. For instance, you are probably reading this book by the light of a nearby lamp. The light bulb has a thin filament inside, which transforms the electrical energy running from the wall socket and through the cord to the filament in the bulb where it is converted into two other forms of energy—light and heat. As the filament illuminates, there is a reduction in electrical energy and an increase in light and heat energies. So energy is not lost but transformed to other forms.

A little bit closer to nutrition, food contains chemical energy in the formof carbohydrates, proteins, fats, and alcohol. Once inside our body the

chemical energy of these substances can be transformed into mechanical energy to power muscular movement and other activities as well as heat to maintain our body temperature. Furthermore, we can store these energy molecules when we cannot immediately use them.