For those of you who have read my blogs regarding the definition of life as a process that evades thermal equilibrium, by now you are probably aware that a definition of life must include the fact that life does many activities of many kinds in order to stay alive and also that ultimately there are two energy sources that life has evolved to use, one is the energy released by the sun because of thermonuclear reactions where earth receives a tiny amount of sunlight on its surface and that energy is transformed into biomass through photosynthesis while oxygen is released and organisms that use oxygen, namely animals convert all the food they eat into biochemical energy while releasing carbon dioxide and waste heat and heat, mainly infrared energy is released into space. The other energy source is generated from within the planet which powers all the plate tectonics and through geothermal energy, there are organisms that are adapted to cold and high pressure at the ocean bottom converting chemical energy into biochemical energy or chemosynthesis as it is called.
Life uses two forms of energy to power all of its vital activities of growth, reproduction, and metabolism but ultimately from organism to biosphere dissipate all the energy that was used to power those three vital functions into the larger environment where it can no longer use the wastes and so must continuously be replenished using those two kinds of energies.
As a process, what life is doing is actually breaking down a chemical gradient and in doing so create disorder or rather life is not so much as using energy to do work but to create entropy. What is entropy? If you have read my previous blog ” Energy, Life, and the Second Law”, then you may know that entropy is basically the amount of disorder that result from any energy converting processes, In physics, there is thermodynamics which studies how energy is converted into many forms, and that is the basis of the first law or that energy can change into many forms and life is in the business of transforming energy. What life cannot do, and this has been confirmed by experiments is that energy can never be created nor destroyed. Life may change energy starting from sunlight into the growth of leaves. Some species of animals can expend energy such as finding food, synthesize enzymes for the breakdown of carbohydrates if the animals is a herbivore as well as synthesizing enzymes for protein digestion if the animal is a carnivore for preying herbivores. Energy is passed first from sunlight into plants, then into herbivores of all sizes from caterpillars up to deers and then up into carnivores such as hawks and bears and up into what is called the food chain, some of that energy is used in supporting metabolism while the rest is dissipated as heat. According the first law, energy is converted but it is not created out of nothing nor is it destroyed. Life is no exception to this rule and the same is true for life, its origin, and its distribution throughout the universe.
As you also know there is a second law which states that disorder increases until no more disorder further increases or rather that entropy increases until it is maximum and that maximum is what is known as thermal equilibrium and nothing changes once equilibrium is achieved.
Ever since the laws of thermodynamics was found, it seems life evades the second law because it is organized and does something unlike an inanimate object such as a crystal. It has structure but it does not do anything. Life can do many things such as grow from the ground, expand into larger territory, swim through the seas, and even wonder about its own origin, future, and destiny. Life may evade equilibrium or death it cannot evade the second law. Why is that? That is because when the second law was first studied, physicist first studied thermal equilibrium by considering what are called “isolated systems” which are basically systems where nothing can come out and nothing can enter. Equilibrium was easy to study since the fact that nothing changes once entropy becomes maximum, certain properties like temperature would be also easy to characterize but in truth, nothing in the biosphere ever reaches true equilibrium and it is because of these two energy sources, the sun and the earth which prevents anything alive from reaching that state of equilibrium and from the fossil record which shows that life on earth, despite extinctions of species, is as old as the earth, and will continue to evolve until the sun goes red giant.
To understand how this is possible, is to focus from isolated to open systems and an open system is the opposite of the isolated system. An open system never reaches thermal equilibrium that is as long as there is a flow of matter and energy in and a flow of matter and energy out. Energy flows into the biosphere from the sun as well as from the earth and whatever is living from bacteria to humans will take advantage of forms of energy such as glucose molecules that are accessible to bacteria to proteins, carbohydrates, and fats that make up a slice of pizza all of which can support the metabolism needed for life. Wastes such as heat and carbon dioxide then leak out into the environment.
Notice that to support organizations wastes must be released and that is as vital and as long as wastes are produced, there can be organization. Also note the importance of the open system which I argued about in depth in my previous blog and only by treating an organism as an open system, we can then see that there is no conflict to the second law. A small region can organize or become disorganize and if you add up the entropies in the surroundings and system, the total entropy increases but also some parts of the system can become organized so entropy can become negative or with more order but the overall entropy increases.
Entropy can be positive and only positive once system and surroundings are considered but at the level of the system, positive or even negative and with negative entropy there is usually a high degree of order and that can be the organelles all performing their functions in an eukaryotic cell, movement of cytoplasm in a cell, cells performing similar functions in a tissue, flow of blood in a small mammal, formation of an embryo, the migratory patterns of birds, and distribution of populations in a savannah, all of which are forms of biological organizations from organism to ecosystem, all of which are examples of negative entropy. A handful of these forms of biological negative entropy can be seen by the videos displaying life processes below
From watching these life processes in action, there is nothing at all random in how these processes are conducted and that beginning at the cellular to the organisimal level, the parts that make up each organism is anything but random. Randomness, on the molecular level is indicative of matter in equilibrium but none of these are in equilibrium and being far from equilibrium, matter in the form of carbon, nitrogen, and oxygen are arranged in two chief important molecules, proteins and nucleic acids, the former is functional and the latter informational. This degree of order that is necessary to carry out these functions in order for the organisms to survive is also a form of negative entropy but at this point you may interject and say that living things are not the only entities with negative entropy. There are crystals such as a quartz crystal which is composed of atoms of oxygen and silicon and since there is a regular array of atoms, the crystal has negative entropy in lieu of the fact that the atoms are arranged periodically throughout in one local region of space. There is a difference between life and the crystal in that the latter is a static object while life is a dynamic object which has the ability to seek out sources of food as well as evolve into new forms with effective ways of finding foods to attracting mates that is life is a dynamic system that evolves through natural selection while it has the ability to find chemical gradients or food for the sole purpose of staying away from equilibrium. There is that crucial difference in that life in all its forms does what it can to stay alive while ultimately breaking down gradients and creating positive entropy something objects in equilibrium can never do ( if it is possible for a crystal to actually seek out energy and matter, then we would have no hesitation in saying that it is alive according to this definition but let’s not complicate the argument further).
Flow of energy is all that is needed and as long as there is the right amount that is not too much nor too little and in the right amounts, then matter can organize itself spontaneously into far from equilibrium structures which could evolve into life and with the imperative of finding ways to survive then life can evolve into various forms with new forms along with new species, and the degree of organization that is negative entropy can to our eyes be of such wondrous and fascinating delights to behold, delights that can inspire the most wondrous works of art and philosophy.
Flower in the crannied Wall,
I pluck you out of the crannies
I hold you here, root and all, in my hand,
Little flower-but if I could understand
What you are, root and all, all in all,
I should know what God and Man is.
Alfred Lloyd Tennyson
Flower in the Crannied Wall. (n.d). All poetry. Retrieved from http://allpoetry.com/Flower-in-the-Crannied-Wall
Martinez, A (2015, August 19). What is Life, Really?[Web log post]
Martinez, A (2015, Sept 9). Evolution and the Second Law can go Together[ Web log post]
Martinez, A (2105, Nov. 24). Energy, Life, and the Second Law [Web log post]
Morowitz, H.J (1968) Energy Flow in Biology: Biological Organization as a Problem in Thermal Physics New York, NY: Academic Press, Inc
Photo and Video Credits:
Ashwin Kumar Cherrapunjee Rain Forests https://www.flickr.com/photos/ashwinkumar/7158995367/in/photolist-bUBHUB-6C64t-r9KW6-pNm6CM-bUBJdg-cbYY5Q-bUBJ92 CC BY-SA 2.0
NOAA Ocean Explorer NOAA Ocean Explorer: NOAA Ship Okeanos Explorer: Galapagos Rift Exploration 2011 – EX1103 Leg2 https://www.flickr.com/photos/oceanexplorergov/6837383487/in/photolist-bqcnUc-5JoavG-6q35rB-8D9zZR-8DcGS1-93kmya-8D9zuP CC BY-SA 2.0
Paul Sullivan Snapdragons 05-11-10 https://www.flickr.com/photos/pfsullivan_1056/4752408638/in/photolist-8eXkvY-6DM5j1-88cKpS-6cUU47 CC BY-ND 2.0
fijimermaid 9 (n.d) cytoplasmic streaming in Amoeba[ video file]. Retrieved from https://www.youtube.com/watch?v=wEK9EdvDz2w
Giampero cai (n.d) Pollen tube growth.[ video file].Retrieved from https://www.youtube.com/watch?v=4Kw2U2E1POM
dan izzo (n.d) Cell division [ video file]. Retrieved from https://www.youtube.com/watch?v=rgLJrvoX_qo
Kanal na Nicknamercho (n.d) Inner Life of a Cell-Full Version. [ video file] Retrieved from https://www.youtube.com/watch?v=B_zD3NxSsD8
Light at Work (n.d) WaveFX-Drosophila 17h Embryo Development.[ video file] Retrieved from https://www.youtube.com/watch?v=rxECLgspbnI
tglab (n.d) Amoebea aggregation and slime mold formation. [ video file].Retrieved from https://www.youtube.com/watch?v=GYu3F8VyGTQ
hnm13 (n.d) CapillaryBloodFlow.wmv. [ video file].Retrieved from https://www.youtube.com/watch?v=QuWhKN1bHLA
Strang Entertainment (n.d) Caterpillar to Chrysalis Metamorphosis. [ video file]. Retrieved from https://www.youtube.com/watch?v=-gsm_ZyJz_s