Originally posted by scottishinnz
Yes, I think there is a great deal of confusion surrounding "life". Mainly because people seem to think that it's some magical substance. It's not. The same ones seem to think it's only magical when it comes to humans though, strangely, they don't think the same when they get their can of "Raid" out!
Life (taken from wiki)
Conventional defin rictly speaking it also describes the production of new cells in the process of growth.
I wanted to do an example for "life", using a vending machine as an example.
1. Homeostasis: Regulation of the internal environment to maintain a constant state; for example, sweating to reduce temperature.
Many vending machines regulate their internal temperatures, cooling for cold drinks, and heating for coffee and the like. Tick
2. Organization: Being composed of one or more cells, which are the basic units of life.
Whilst vending machines are not composed of cells, their body design in some ways represents a "cell". Cross
3. Metabolism: Consumption of energy by converting nonliving material into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.
Yes. Energy is used in the manufacture of vending machines, and they then require an energy "metabolism" to continue functioning. Tick
4. Growth: Maintenance of a higher rate of synthesis than catalysis. A growing organism increases in size in all of its parts, rather than simply accumulating matter. The particular species begins to multiply and expand as the evolution continues to flourish.
No. Vending machines do not grow. Cross
5. Adaptation: The ability to change over a period of time in response to the environment. This ability is fundamental to the process of evolution and is determined by the organism's heredity as well as the composition of metabolized substances, and external factors present.
Yes. Vending machine design can, and has changed through time.
6. Response to stimuli: A response can take many forms, from the contraction of a unicellular organism when touched to complex reactions involving all the senses of higher animals. A response is often expressed by motion, for example, the leaves of a plant turning toward the sun or an animal chasing its prey.
Yes. You put money in, you get fizzy juice out.
7. Reproduction: The ability to produce new organisms. Reproduction can be the division of one cell to form two new cells. Usually the term is applied to the production of a new individual (either asexually, from a single parent organism, or sexually, from at least two differing parent organisms), although strictly speaking it also describes the production of new cells in the process of growth.
No. Vending machines don't reproduce.
So, as we can see, whilst vending machines do fulfil some of the requirements for life, they are not alive themselves.
If we look at viruses, they fulfil 6 of 7 criteria.