Life
From RationalWiki
Life is like a box of chocolates, in the context that chocolate is extracted from the seed of the tropical cacao tree, which is alive. We are all alive. You, me, that guy at the train station, and that mole on your back with the long hair sticking out of it, are all "life".
Life is very difficult to define[1] but "everyone knows it when they see it"[2]. Unfortunately when we get down to microscopic life forms the obviousness of life is not so universal. Most life performs the following essential functions: adaptation, metabolization, and some mode of reproduction. However, these functions are debatable with organisms such as viruses.
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[edit] Requirements for life
Life has to be inherited through something hard enough and/or protected enough to survive while simultaneously being soft enough to allow mutation. Something very similar to DNA, or of course RNA, is almost certainly required. Various other compounds have been proposed but all require carbon compounds. No scenario has been realistically proposed which does not require liquid water in sufficient amounts to completely envelop a basic reproducing unit such as is represented by a cell on Earth. Viruses and some primitive archaebacteria can exist in totally dry environment but the former are not normally classified as alive and the latter do not perform any life functions (e.g. respiration) in the absence of water. The first life on earth probably existed by trapping a small volume of water in a sphere of emulsion created from hydrophobic/hydrophilic molecules.
The only other requirement for life is an energy source. Two classes of energy source are recognized:
- primary (sunlight, thermal gradient, chemical reaction)
- secondary (interaction with other life forms using primary or other secondary source)
[edit] Fire
A wildfire demonstrates all the characteristics needed for life. It breathes oxygen, consumes food (wood), grows, reproduces by division or by spreading spores (embers) through the air, and eventually dies.
[edit] How to get a Life
- See the world (but not on a cruise ship)
- Enjoy good food
- Get drunk (occasionally)
- Get stoned (at least once, but not too often)
- Have great sex with people you really like
- Enjoy a wide range of music, literature and art
- Make a stranger happy and ask nothing in return
- Treat other people as you would expect them to treat you
- Appreciate what you have, rather than strive for what others have
- Remember that life is not a dress-rehearsal for something later
- Laugh (as often as you can)
- Don't concern yourself with the perceived failings of others
- Leave the world in as good shape as possible for those who come after you
- You're gonna die. Accept it!
- Click on the little red box with the white "x" on the top right of this screen.
[edit] See also
[edit] Footnotes
- ↑ An attempt to define life
- ↑ Like Pron!
