Life is an expression of the mind's vision. This indicates that Life, the Source, utilizes your ideas, mental pictures, as instructions to construct your reality in the material world. Life is the manifestation of your mental pictures into actual reality. To express means to make known, to say, to articulate, to communicate, and to transmit. All living things express their nature through three distinct forms of communication: sight, sound, and sense perception. Sight can be thought of as the source of inspiration for artists and designers. Sound is used by musicians to create harmony and melody. Sense perception allows us to experience the physical world around us.
Life is also an illusion, a virtual reality created by the mind. We think this world is real because all we experience are our perceptions of the world through our senses. Our brain makes sense of what it receives from our eyes and ears and combines it with data from our other senses (such as touch, taste, and smell) to produce a seamless picture of the world. This picture is called a model of the world in the mind.
You may wonder how something that is only a model of the world could be considered true. The mind believes in its illusions just like it believes in the reality of life; both are false but useful inventions. Illusions provide us with protection, guidance, and enjoyment. There is no such thing as death because nothing is truly real at any point in time. All is energy, and energy can be re-created at will.
Existence as we know it is a temporal notion defined by minutes, hours, days, and years in the many seasons of life. However, it is made up of time, space, and energy in its metaphysical composition. Peace is the means by which we might live in love, pleasure, and togetherness... forever.
Life is the component of existence that processes, acts, responds, assesses, and grows (reproduction and metabolism). The key distinction between life and non-life (or non-living entities) is that life requires energy for physical and conscious growth. Energy can be derived from within or without the organism.
Organisms are classified into three main groups on the basis of how they obtain their energy: autotrophs, heterotrophs, and phototrophs. Autotrophs produce their own food by photosynthesis; they include plants. Heterotrophs eat other organisms or their products (e.g., bacteria) to get their energy; they include most single-celled organisms. Phototrophs use the light energy in sunlight to create organic compounds with which they build their cells. They include algae and some bacteria. Humans are heterotrophic because we must eat other things to survive. However, we can convert part of our food into gasoline using a process called fermentation and then consume the alcohol created.
The study of life forms includes the classification of living things according to their structure, function, and behavior. Scientists also investigate how species evolve over time by comparing different individuals or populations of organisms with each other and with related species.
Scientists use several methods to study life forms including morphology, biogeography, taxonomy, cytology, chemistry, and genetics.