Scaling down astrophysical world of gravitation in biological microworld
Iresh Ranjan Bhattacharjee*
*Institute for Intrinsic Gravitation Biology
In contrast to astrophysical world (106 to 1036 m) in macroscopic length scale, or quantum gravity at microscopic world (10-12 to 10-36 m); biological microworld at mesoscopic scale (100 to 10-12m ) is kept outside the purview of gravitation because of historical oversight. Interaction phenomena of mutual gravity are now-a-days getting some attention on initiation of space life science research at microgravity. Fluids constitute 50-90 % of the total biomass. Under buoyant property of such extra-ordinary quantity of fluid, biomass bounded in closed surface, get advantage of apparent reduced ‘weight’ under same quantity of ‘mass’. In terms of gravitation, distinction between ‘living’ and ‘non-living’ mass has not yet been framed out. Living mass can keep independent gravitation identity because of spontaneous generation of metabolic energy against binding action of self gravity. A ‘planet within planet’ situation arises at macromolecular, cellular and multi-cellular levels bringing self gravity into the scenario. So there is enough scope for scaling down astrophysical world of gravitation. The paper examines various aspects of scaling down operations with support of biological evidences and reasoning, as enumerated in new biophysics topic ‘Self gravitation bio’.
The 'Self gravitation bio', a new topic has been annexed in the study of biophysics by the Biophysical Society (USA) in 2008 on being presented by the author . Self gravitation bio contemplates the concepts of gravity to the microscopic world of life science. Gravity as variable in life science was proposed for the first time. But many of its working remains elusive. Gravity is customarily considered as long distance force acting on massive body at macroscopic length scale. Presence of gravity at macroscopic scale at 106 to 1036 m, especially from planet to universe is virtually understood through various astrophysical principles. Similarly presence of gravity at microscopic scale at 10-12 to 10-36 m is being felt under particle physics mainly through quantum gravity. At mesoscopic length scale, interaction phenomena of mutual gravity are now-a-days getting some attention after initiation of space research on life sciences at microgravity. In contrast to astrophysical world (106 to 1036 m) at macroscopic length scale, or quantum gravity at microscopic world (10-12 to 10-36 m); biological micro world at mesoscopic scale (100 to 10-12m ) is kept outside the purview of gravitation because of historical oversight. Under equal quantity of gravitational mass, distinction between living and non-living is never projected in proper gravitational perspective. In living biomass, there is extra-large quantity of fluid, buoyant force of which was, however, never given prominence. Buoyant force of denser fluid apparently reduces gravitational load, thereby enhances the distance of separation between two gravitating bodies. Biomass mostly remains under neutral buoyant condition. As such under a closed surface within a membranous boundary, it can become an independent gravitating body and can interact with other gravitational bodies, as per general astrophysical principles of gravitation. Under such a state of affairs, if astrophysical principles are allowed to be scaled down to biological micro world, there would be great break through to understand various intricacies, still present in living organisms. Easiest way for such distinction, at least at preliminary level of investigation, is to carry out feasibility of scaling down larger mass to smaller mass on the principle of equivalence.
So in this paper, we would examine various aspects of scaling down operations with support of biological evidences and reasoning, as enumerated in new biophysics topic ‘Self gravitation bio’. To put into affect the concepts of self gravitation bio and to provide realm of its application to the living world, the paper is divided into four parts. In Part I, we will speak on possibility of apparent seclusion (working as astrophysical distance) due to presence of extra-large quantity of fluids in membrane bound structure of closed surface, significant force of nanometer scale free fall acceleration at picometer size biomass, process of homogenous and heterogeneous accretion under reduced weight, transmission of fluid pressure with increase in mass. In part II, we will discuss input and output of metabolic energy in living organism compared to radiation energy of the astrophysical bodies, basal metabolic rate proportional to ¾ power of an animal's mass, division in metabolic energy for working against intrinsic and extrinsic gravity including stoppage of metabolism under reduced level of fluid. In part III, we will try to understand planet within planet situation in biological micro world on being secluded and under discontinuous condition. And finally in part IV, we would discuss various biological evidences and reasoning in support of conjecture on gravitational phenomena.
Part I: Mass and weight under fluid
I(a) Role of extra-large quantity of fluids in self gravitating environment of living
Presence of extra-ordinary quantity of fluids in living bodies is one of the most poorly understood aspects in life science. On average, the body of an adult human contains 60% water. Most of the water in the human body is contained inside cells. For example, a 70-kg man is made up of about 42 litres of total water- 28 litres is intracellular water; 14 litres is found in extracellular fluid of which 3 litres is blood plasma, 1 litre is the transcellular fluid (cerebrospinal fluid, ocular, pleural, peritoneal and synovial fluids), 10 litres is the interstitial fluid (including lymph), which is an aqueous medium surrounding cells. Also, all our vital organs contain different amounts of water: the brain, the lungs, the heart, the liver and the kidneys contain a large quantity of water – between 65 to 85% depending on the organ, while bones contain less water (but still 31%). Most interesting fact is that whatever large quantity of fluid present, their accumulation generally varies according to age, context etc. For instance, the body of a newborn is composed of more water (75%) than that of an elderly person (50%). Also, the more muscular a body is, the more water it contains. Conversely, the more fat in the body, the less water the body contains – as body fat has little water. In case of fetus it follows a distinct curve. For instance, at 10 weeks gestation, amniotic fluid is 10 to 20 milliliters of volume, at 16 weeks gestation ~250 milliliters, at 33 weeks gestation ~800 milliliters, at 38-39 weeks reaches a plateau of ~1000 milliliters, and finally decreases at 40 weeks to ~800 milliliters. In fact, the total amount of water in human body is found in three main locations: within cells (two-thirds of the water), in the space between cells and in blood (one-third of the water). Importance of such large volume of water in living bodies has not yet suitably defined in life science. Fluids not only play a role for transportation, but can create apparent seclusion environment in universal gravitational field. Resultant force vector, due to up thrust of fluids against vertical gravitational acceleration, would alter loading pattern in biomass, out of change in external reaction force, following Archimedes Principle.
I(b) Property of fluids to avert gravity’s central pull
In water, hydrogen atoms are attached to the oxygen atom causes one side of the molecule to have a negative charge and the area in the opposite direction to have a positive charge. The resulting polarity of charge causes molecules of water to be attracted to each other forming strong molecular bonds. Water again has a high surface tension due to its adhesive and elastic property and tends to aggregate in drops on averting gravity's central pull. Thus under a closed surface, fluid has the capacity to avert gravity's central pull and to provide desired up thrust for maintaining distance in terms of astrophysical seclusion. The situation has been visualized in Illustration 1, where cytosol in animal cell i.e. fluids that contains organelles also works against central pull of self gravity, analogous to up thrust or buoyant force that works against earth's gravity.
Illustration 1. Cytosol in animal cell i.e. fluids that contains organelles works against central pull of self gravity, analogous to up thrust or buoyant force that works against earth's gravity.
I(c) Buoyant force of fluid seclude living mass from onset of gravity
An egg floats on saline water, on working against earth's gravity, due to buoyant force. Buoyancy acts against the force of gravity and so makes objects seem lighter with respect to gravity. At microgravity, everything floats in absence of gravitational attraction. These are phenomena for attraction or lack of attraction for mutual gravity. Similarly an intravenous drip of ‘isotonic’ saline not only corrects disturbances in water and electrolytic balance, but also provides buoyant force against gravitational weight .
I(d) Under neutral buoyancy, self gravitating biomass gets secluded on reducing gravitational drag force
Amniotic fluid index (AFI) is a rough estimate of the amount of amniotic fluid (expressed in cm) in pregnant uterus and is an index for the fetal well-being in mothers' wombs. Through ultrasonograph, deepest, unobstructed, vertical length is measured. An AFI between 8-18 is considered normal. An AFI < 5-6 is considered as Oligohydramnios where as > 20-24 is considered as Polyhydramnios . Proper role of AFI remains elusive in health science. It is considered as a part of the undefined biophysical profile.
Similarly, cytoplasm is composed mainly of water and also contains enzymes, salts, organelles, and various organic molecules. Spaargaren  coined the term ‘metabolically inert infrastructure’ (MII)to describe liquids in the cell. In unicellular organisms, cell’s environment- viz. a substratum beneath it, a liquid medium around it and neighboring cells beside it; whereas in multicellular organisms, aggregation of cells and tissues with sufficient intra and extra-cellular matrix in totality affect ‘life’. The mucilaginous jelly surrounding the embryo, or adequate depth of liquid media for multiplication of green algae, cultural media for bacteria, living host for viruses, plasmid or bacteriophage for transfer of gene from one chromosome to other etc are some of the examples of undefined biophysical profile. Without MII support death occurs. It is presumed that MII or ‘medium’ play the role of ‘astrophysical distance’, due to co-moving non-accelerated position of the metabolically inert infrastructure (MII) that are relatively stationary or at constant velocity, or non-aligned or acting in opposite direction of the energized accelerated self gravitating biomass or of the steady state supporting inertial reference frame at the specific point of time.
I(e) Kids imitate playing football by the adult
Soccer is being played by all ages. Age wise, not only materials, circumference or weight of ball may differ but playing standard would be different. For youth/adult, ball may be of leather having 70 cm circumference and 450 gram weight. For kids, ball would of lighter materials having circumference bigger than 30 cm and weight could be less than 100 grams. But one thing is common that everyone will play as per individual capabilities. Kids imitate playing football by adult. So for judging kid’s play, one can compare their performances quantitatively on scaling down the performance of adult.
I(f) Nanoscale acceleration due to self gravity in Angstrom scale biomass
The length of macromolecules of biomass is traditionally measured in Angstrom scale. An angstrom or ångström (Å) is a non-SI unit of length equal to 10^-10 metres, 0.1 nanometres. In biology, protein aggregation or folding starts after formation of some critical mass that spread up to certain critical distance (say, 2.8-3.0 A^0). Under secluded gravitating environment, nanometer level free fall acceleration would be a tremendous force for femtometer size or in Angstrom length scale macromolecules. Let us interpolate and visualize the phenomena with some superimposed data. Though literature on neutral buoyant force of amniotic fluid and utero as well as ex utero measurements is scanty, but some assumptions could help us to visualize the situation. A normal weight of a human child at birth is say 3200 gm on earth but at moon its weight would be 531 gm. The actual mass of the human brain is about 1400 grams; however, the net weight of the brain suspended in the cerebrospinal fluid (CSF) is equivalent to a mass of 25 grams. i.e. what is 56 gm in human body will appear to be 1 gram only under neutral buoyant condition of the brain. Ignoring difference in the value of neutral buoyancy in cerebrospinal and amniotic fluids, due to differential presence of salt and other matters, acceleration due to self gravity in 0.792 gram at 16 days of gestational age of mice with radius 9.9 mm, separated by neutral buoyant force, as provided by Junwu Mu et al , using standard formula g(s)= GM/R^2, comes to be about 5x10^-9 m/s^2. That is free fall acceleration to the tune of 5 nanometer per second square in a massive body of the planet may be negligible, but in a secluded (~ vector wise discontinuous/ diverted) living mass of the size 9.9 picometer (9.9x10^-12 meter), acceleration of 5 nm/s^2 is quite a significant force. Mass would have experienced a force of 7.70-8 N downwards due to gravity, had it been outside the fluid. But under neutral buoyant condition, mass would experience a upward resistance force/ upward force of the water of 0.14-8 N. Thus upward force would be greater than downward force due to planetary gravity.Thus mass remain same, but its weight gets reduced under neutral buoyant condition.
I(g)Addition of mass invites addition of weight in the cell
Mass is the fundamental parameter of cell growth. On the basis of source of cellular carbon as a mode of nutrition, there are mechanism of energy conversion into biochemically active form of ATP through principal metabolic type in which phototrophic organisms uses electromagnetic radiation (light) and chemotrophic organisms gained energy by oxidation-reduction reactions of nutrient substrate, irrespective of the way in which the biochemical energy is obtained, whether by respiration or fermentation. In case of organotrops, organic compounds uses hydrogen as donors, where as in case of lithotrops, inorganic hydrogen uses NH3, H2S, S, CO2, Fe^2+ and others as donors. Green plants, cyanobacteria and purple sulphur bacteria are photolithotrops, nitrifying bacteria are chemolithotrops and animals and the vast majority of microorganisms are chemo-organotrops. When lithotrophy is linked to autotrophy, it is photoautotrops, chemoautotrops & chemoheterotrophs. It is to be remembered that due to individual mode of nutrition, there is constant addition and reduction of mass in a living cell. On the average, cell mass must double from birth to division during steady-state growth in a culture. But this requirement need not apply precisely to cell length or volume, both of which are critically dependent on cell shape, which is altered at division. It has been established that cell volume is only proportional to cell mass during the growth cycle when cell buoyant density is constant. On the other hand, cell mass may be thought of as an indicator of the number of molecules needed to sustain a self replicating system. Therefore mass (added or get compressed) invites addition of weight within the closed surface of the cell. Such addition of weight creates a pressure within the closed surface of the cell, similar to 'The Crow and the Pitcher' story, when thirsty crow drop pebbles one by one, until the water rises to the top of the pitcher, allowing it to drink.
I(k) Transmission of fluid pressure in cell
Biologists consider external fluid stresses, the internal driving moments, and the passive elastic resistance is the primary cause of swimming of macromolecules over fluids. Pascal's law or the principle of transmission of fluid-pressure is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure variations (initial differences) remain the same. Now imagine, had there been no resistance, equal and opposite bounding force, there would not have been an unbalanced pressure to exert. So there is a need for compressive action. Here elastic force cannot be a substitution for gravitation.
I(k) Homogeneous and heterogeneous accretion in living cell
According to current astrophysical theories, the planets like Mercury, Venus, Earth and Mars formed over a time period of 100 million years ago in three stages viz. planetesimal, planetary embryo and finally planet formation . During formation of self gravitating body, particles are collected within a giant disc of gas through process that probably includes both homogenous and heterogeneous accretion. In homogenous accretion, similar elements stick together, creating a solid mass. The heavier elements sink to the center because of self gravity, creating the solid core. In heterogeneous accretion, particles of metal first stick together, creating the core. Lighter elements stick to this core as it continues to cool.
During formation of living bodies, though constitution and materials are different, similar situation arises. Under neutral buoyant conditions, molar mass and density of macromolecules decide their 'central tendency' or mutual aggregation, as demonstrated in Illustration 2. For instance, in case of nucleic acid, molar mass of DNA fragments etc. is say, 1000 - 5,000,000 g/mol. Therefore under near neutral buoyant condition, nucleic acid which has higher molar mass or molecular weight as well as density, would tend to remain at the central core due to attraction of self gravity. It is to be noted that nucleic acids contain phosphorus, in addition to C, H, N & O. Unlike proteins, nucleic acids contained no sulfur. The DNA polymer is much larger and may extend up to 2 meters in length. The DNA is packed tightly and fit in that small volume. The molecular weight of double stranded DNA is approximately 660 x the number of base pairs. The genome of E. coli, for instance, contains 4,639,221 base pairs. The molecular weight of one E. coli genome, therefore, would be 660 x 4,639,221 = 2,840,000,000 g/mole. Molecular weights for the DNA from multicellular organisms are commonly 10^-9 or greater. The DNA from the smallest human chromosome is over ten times larger than E. coli DNA. The buoyant force is directly proportional to volume of the body submerged in the fluid. As volume of nucleic acid is comparatively less than protein, potential energy of gravitation could move to the central position. Therefore accumulation of nucleic acid under tightly packed condition at the central position possibly demonstrates presence of compressive central force of self gravity.
Illustration 2. Macromolecules find position according to individual molar mass, density and characteristic solubility under neutral buoyant conditions. Higher the molar mass, central would be its location.
Proteins, on the other hand, which have intermediate molar mass or molecular weight as well as being comparatively less denser than nucleic acid, would remain in intermediate position or as heterogeneous accretion in self gravitating environment under free floating condition. In case of fats and lipids, molar mass are also intermediate. But the density of fats and lipids is less than protein on equal volume basis. So fats and lipids are under duress of self gravity to occupy the peripheral position under free movement (free fall) condition. Hence finding of lipids in cell membrane is not accidental, but a simple instance of comparatively delayed action of self gravity in attracting less dense materials compared to high dense materials at particular point of time. The solubility of carbohydrate (approximately 683 g/ liter) however makes its distinct property as being miscible from other similar situated macromolecules. Depending upon the timeline of formation along other types of macromolecules, nucleoid in prokaryote and nucleolis or nucleus in eukaryote would tend to lie in the central position due to priority of inward attraction of self gravity to drag higher molecular weight at the initial stage of cell growth. Such higher weight macromolecules subsequently become lighter than the equivalent volume of cytoplasmic fluid due to concentration of salts, matrix and therefore could float away to the outward periphery from the central position of self gravity due to side thrust generated by the co-moving denser fluids. At this late stage, denser macromolecules are pushes outward due to hydrostatic or turgor pressure. With the decrease in mutual attraction due to increase in distance, twin centre of mass forms, each exhibiting individual gravitating barrier.
From the evidences and reasoning above, especially apparent seclusion (working as astrophysical distance) due to presence of extra-large quantity of fluids in membrane bound structure of closed surface, significant force of nanometer scale free fall acceleration at picometer size biomass, process of homogenous and heterogeneous accretion under reduced weight, transmission of fluid pressure with increase in mass, it can be presumed that a self gravitating environment prevails in the living cell or organism. Such environment is therefore conducive for scaling down the astrophysical world to biological microworld.
PART II: METABOLIC ENERGY
II(a) Input and output of metabolic energy in living organism
Although planets and stars are neither in thermal equilibrium with their surroundings nor perfect black bodies, black-body radiation is used as a first approximation for the energy they emit . In living organism, situation seems little different, but major outline remains same (Illustration 3).
Illustration 3. Schematic diagram shows input and output of metabolic energy in living organism. Rate of basal metabolic energy, resting metabolic energy, physical activity level and generation of heat and radiation are the primary mode of distribution of energy in living organism.
Anabolism (build-up) and catabolism (break-down) through various process including photosynthesis and respiration respectively result a ‘change in masses per unit volume’ continuously, resulting contraction and relaxation alternately in living body. The living body converts energy stored in food into prominent three mode viz. work, thermal energy, and/or chemical energy (including that is stored in fatty tissue). The rate at which the body uses food energy to sustain life and to do different activities is called the metabolic rate, and the corresponding rate when at rest is called the basal metabolic rate (BMR). About 75% of food calories are used to sustain basic body functions included in the basal metabolic rate. The energy consumption of living organisms during various activities can be determined by measuring their oxygen use, because the digestive process is basically one of oxidizing food. For instance, total power consumed at rest (Watt) and total Oxygen consumption (mL/min) for an adult human is 85 and 250 respectively. In different organs, there are liver & spleen 23 and 67, brain 16 and 47, skeletal muscle 15 and 45, kidney 9 and 26, heart 6 and 17, other 16 and 45 respectively.
II(b) Basal metabolic rate is proportional to the ¾ power of an animal's mass
But most interesting fact is that basal metabolic rate (R) is proportional to the ¾ power of an animal's mass (M). This relationship, known as Kleiber Law [7,8], holds from simple organisms to most complex ones, from microbes to giant blue whales across 18 orders of magnitude in body mass . Part of mass (say 2/3 to ¾ or 66 to75%) is expended towards maintaining metabolic rate. On other hand, 100 percent of the same mass works towards generating self gravitational potential energy. There is thus a huge difference (a tug-of-war) between kinetic (metabolic) and potential (gravitational) energies. When force of gravity and inertia are balanced there will be no change of motion, object remains stationary i.e. net force is zero. When metabolic energy is put at the rate of 10-12 to 10-6 kcal/hr, it can move unicellular organisms. Similarly cold blooded animals can be in motion when metabolic rate is 10-8 to about 100 kcal/hr. Warm blooded animals do the same work with metabolic rate having less than 100 to 103 kcal/hr. Thus presence of metabolic energy can be felt taking into account both intrinsic and extrinsic ‘gravitational force’ with resting metabolic rate (RMR) for meeting most of the demands on working against self gravity where as physical activity level (PAL) could be mostly to meet demands for working against extrinsic gravitational force. This will be clear from the under mentioned discussions.
II(d) Broad division in metabolic energy for working against intrinsic and extrinsic gravity
Take an example on movement of dome shape arc structure of human thoracic diaphragm. Here potential energy of self gravity contracts its dome shape structure. The inertia attempts to bring back contracting surface to original position. Kinetic energy of metabolism works against it, thereby, allowing the dome shape structure to relax. Unbalanced forces causes change in motion in a curved surface in speeding up and slowing down (Illustration 4). Resting metabolic rate (RMR) is therefore primarily involved in such internal activity against self gravity.
Illustration 4. During movement of human thoracic diaphragm, potential energy of self gravity contracts the dome shape structure. The inertia attempts to bring back contracting surface to its original position. Kinetic energy of metabolism works against it, thereby, allowing dome shape structure to relax. Resting metabolic rate (RMR) is involved in such internal activity against self gravity.
On the other hand, raising a ball through a height above earth’s surface by hand involves metabolic kinetic energy against potential energy of earth’s gravity and invites spending metabolic energy as per physical activity level (PAL) on contracting and relaxing muscles (Illustration 5).
Illustration 5. Raising a ball through a height above earth’s surface involves metabolic kinetic energy against potential energy of earth’s gravity as well as spending metabolic energy as per physical activity level (PAL) on contracting and relaxing muscles.
II(e) Reduced level of fluid stop metabolism
Studies in the brine shrimp  showed that reducing the amount of water in a cell below 80% of the normal level inhibits metabolism, with this decreasing progressively as the cell dries out and all metabolism halting at a water level about 30% of normal. From the perspectives of gravity an explanation to this observed phenomenon could be possible. With inadequate depth of supporting fluids, macromolecular mass in the interior lost their gravitational seclusion identity- metabolic kinetic energy gets over powered by potential gravitational energy.
Electromagnetic radiation, having specific spectrum and intensity, depending on the temperature of the astrophysical body works against compressive action of the self gravity. The operation of metabolic energy in living organisms seems little different from the working of the radiation energy.
Part III: Scope for incorporation of gravitation at cellular level
III(a) Mass based ten storied biological particle hierarchy
Ten storied particle hierarchy in terms of smallest to largest mass in multi-cellular living organism consists of sub-atom, atom, molecule, compound, organelles, cells, tissue, organ, organ system and organism. At sub-atom (particle) level, strong and weak nuclear forces work as the binding forces. Electrostatic forces are dominant at atom, molecules and up to compound level. At organelles level, joint action of system of various macromolecules like nucleic acid, protein, fats and lipid, carbohydrates starts in a membrane bound structure and that too, on being secluded under buoyant forces of fluids. Gravity therefore could become a binding force of diverse macromolecules from organelles level.
III(b) Possibility of having stronger gravitational force in biological soft matter
It is to be remembered that biology starts in non-Newtonian state as soft condensed matter in which the viscosity changes with the applied shear stress. Unlike fluid (say, water) which could return back to its original position after withdrawal of stress, soft matter displays a range of fascinating generic properties such as ability to ‘self assemble’ into complex structures, a large number of internal degrees of freedom, weak interactions between structural elements, and a large thermal fluctuations at room temperature, a wide variety of forms, sensitivity of equilibrium structures under metastable states to external conditions. The Newton’s inverse-square law would be valid if there is no additional dimension. However, if there are two additional dimensions, the dependence of the gravitational force would change from 1/r2 to 1/r4, or the gravitational potential could take the following form:
r>>R (Newtonian) (2)
If dividing by 1/r2 is a small number, dividing by 1/r4(twice of 1/r2) can make the corresponding gravitational force much stronger [11,12].
On the other hand, logically electromagnetic forces cannot completely overwhelm gravity in the world around us. Most things are composed of an equal amount of positive and negative electric charges whose forces cancel each other out. Whereas electric and magnetic forces are clearly bipolar, gravity is generally assumed to be always attractive so that no analogous cancellations occur, except manifestation of inertia with increase in mass from macromolecular level.
III(c) Gravitational anchor is a criterion for manifestation as living
A single cell cannot survive in isolated way, unless it is anchored by inertia. A minimal inertial mass is required for survival. In plant tissue culture, unless a callus (“explants”) of say above 500 mg  or suspension of cultures of say, 3-4 cubic centimeter (in terms of PCV - packed cell volume) is used, it is difficult to maintain continuity of life and growth from individual cells. Similarly in the final volume for cell culture, maintaining cell density as low as 3 x 105 to high of more than 10–15x 106 cells/ml of inoculums are required. Why a minimum mass is required for cell culture under multi-assembled single cell condition. Is it for anchorage? There is a literary proverb that “A Rolling stone gathers no moss”. This is not only a literary proverb but based on scientific observation and fact of the commoners. In formation of stars, relatively dense concentrations of interstellar gas and dust (molecular clouds) are required.
III(d) Energy producing organelles are little away from central position
Within the bounds of closed surface of structural membrane in a living cell, central equilibrium position of the floating macromolecules may get destabilize due to opposing force of inertia with increase in hydrostatic pressure of compressed fluids. Metabolic energy of biomass works as kinetic energy against potential energy of self gravity. Energy producing organelles like mitochondria, chloroplast etc are therefore always little away from central position (Illustration 6), as in gravitating system, core position have highest gravitational load, as if the entire mass in the sphere of influence would have been concentrated at that point.
Illustration 6. A fluorescent image of an endothelial cell. nuclei (stained blue) are almost in central position with some eccentricity. Energy producing organelles like mitochondria (stained red) are little away from centre. Microfilaments (stained green) act as anchor in the cell. (Photo source .
III(e) Understanding planet within planet situation in biological micro world
Gravitation in microscopic biological world can only be imagined under plant within planet situation. Neucleus and neucleolus of a cell can be considered as ‘core’ segment of the self gravitating interior of a living cell, as shown in Illustration 7. In planet within planet situation, eccentricity of the core is one of the distinguishing features. Deviation from centre or not having same centre is known as eccentricity. For instance, plasma cells are large lymphocytes with a considerable nucleus-to-cytoplasm ratio. They have an eccentric nucleus. For instance, plasma cells are large lymphocytes with a considerable nucleus-to-cytoplasm ratio. They have basophilic cytoplasm and an eccentric nucleus. The Archimedes principle provides not valid but only an average approximation for the buoyancy force of nucleus submerged in surrounding fluid when the size of the nucleus is much smaller than its distance away from the center of the surrounding matrix . Due to compression inside interior of the bounded structure, hydrostatic pressure increases with depth from the surface. Flux of a vector field of gravitation under such a situation can be analyzed in a closed surface in three-dimensional space, especially considering it a Gaussian surface on application of divergence (Gauss's) theorem.
Illustration 7. Pictures showing (a) neucleus and (b) neucleolus as the ‘core’ segment of the self gravitating interior of the living cell. Pictures are taken on using green fluorescent protein (GFP) tagged proteins (photos with permission from Jeremy Simpson and Rainer Pepperkok ) and under inverted colour (a’, b’) respectively.
From the aforesaid facts and analysis, it is evident that force of gravitation could become a binding force for diverse macromolecules from organelles level, with a clear edge over competitive electrostatic force. Electrostatic force is a charge based force, where as gravitation is mass based. Particle hierarchy in living organism is after all mass based. The phenomena like energy producing organelles located little away from central position, description of planet within planet on considering eccentricity of nucleus, as if a core segment, on application of divergence (Gauss's) theorem are of worth notice. All these indicate that there is enough scope for scaling down of astrophysical world to biological micro world.
PART IV: Various evidences and reasoning in support of gravitational phenomena
IV(a) Biological growth means increase in mass
Biological growth means either an increase in number of cells (hyperplasia) or increase in cell size (hypertrophy). Irrespective of expression, growth means increase in mass. However, growth do not occur in uniform arithmetic progression - there is retardation in the percentage increase. The per cent rate of growth is afterwards slowed down in spite of best nutrient supplementation. Say, a day one chick in embryo weighs 0.002 grams, on 7th day, it attains 0.57 gram and at day 14 and 20, it attains 9.74 and 30.21 grams respectively. Subsequently at 8 weeks it weighs about 1200 grams. It is still considered a puzzling feature in developmental genetics , ‘how does genome appreciate that its activities need to be slowed down after the phenotypic task is over’. To bridge the gap in scientific understanding it is postulated that phenomena is due to building up of critical level of growth limiting substance at particular period of growth. What could be the critical growth limiting factors (and not substance)?
Such slowing down in the rate of growth by an unknown factor could be explained with the astrophysical principles of gravitation. Gravitation force increases with increase in Newton’s mass. The gravitational mass is a ‘charge’: an object feels a gravitational force in proportion to its gravitational mass, just as it would feel an electromagnetic force in proportion to its electric charge. There would be an increase in gravitational force, for example, with increase in mass under same distance or under same mass with decrease in distance, even in miniature scale.
Research indicates that physical parameters like ‘membrane surface area’, ‘pathways’ and ‘cell size’ determine cellular growth rate. The increase in growth rate in fast-growing yeast Kluyveromyces marxianus can be explained by a dominant (80%) limitation of growth by the group of membrane processes including membrane surface area. Simultaneous activation of membrane processes may be what is required to accelerate growth of the fastest-growing form of eukaryotic life and may be of potential interest for single-cell protein production . Similarly it was shown that nutrient-dependent pathway and cell size controls growth rate in the Gram-negative bacterium Salmonella typhimurium or Gram-positive model organism Bacillus subtilis . From both the findings, it is clear that ‘membrane surface area’, ‘pathways’ and ‘cell size’ are those that can be manipulated on controlling volume by a compressive gravitation force.
IV(b) Accretion mass and quantity of fluid in various stages of growth
The body of a newborn is composed of more water (75%) than that of an elderly person (50%). The accretion mass is therefore 25% and 50% respectively. Higher the accretion mass, higher would be gravitational pressure, as common in any astrophysical body (Illustration 8).
Illustration 8: Higher the accretion mass, higher would be gravitational pressure. Accretion mass for new born is 25% whereas in case elderly person it is 50%.
IV(c) Retardation in percent increase in growth
Retardation in percent increase in growth is common to all gravitating stellar bodies of the universe, where internal pressure opposes invisible self-gravity . Miniature size of the biological bodies seems do not show hindrance to mimic gravitational phenomena. At infant stage, there would be higher metabolic energy but lesser gravitational energy. At adult stage, there would be equilibrium between metabolic and gravitational energy. At old age, there would be lesser metabolic energy and high gravitational energy.
IV(d) Isostatic balance in a gravitating body also operates in living bodies
Isostatic balance i.e. balances between lighter and heavier mass in relation to centre of self-gravity is a common phenomenon in all gravitating bodies including earth. The basis is the Pascal's law and particularly its consequence that, within a fluid in static equilibrium, the hydrostatic pressure is the same on every point at the same elevation (surface of hydrostatic compensation). Therefore in general terms, subduction in an area is compensated by formation of mountain on other side due to action of self gravity of the earth.
In biological growth, isostatic balance also happens around self-gravity (ignoring minor circumstantial exceptions). Head (especially back) consists of solid mass of brain, muscle, and bone which is much heavier (greater specific gravity) than water on equal volume basis or than of bone and muscle or fatty and air-containing body tissues. During and after embryonic growth, brain’s higher weight is compensated by continued growth towards human leg- an isostatic balancing act of self gravity around central position. Similarly plant growth occurs through balance between roots and shoots alternately, though root growth dominates during early period. Roots are comparatively denser than shoot on equal volume basis.
IV(e) Balance is the Law of Life
From giant universe to tiny microscopic bacteria, though materials for constitution differ, there is one phenomenon common to all - "Balance is the law of life". In giant star, internal pressure opposes self gravity. Radiant energy generates due to balance between outward internal pressure and inward gravitational pressure- keeps sun shining. In living organism outward metabolic energy opposes inward invisible force of self gravity (Illustration 9). Life continues so long balance is maintained. So "keep balance"- that is the universal rule to survive and living organism cannot remain exception.
Illustration 9. Balance is the law of life. Potential energy of inward force of gravity must be balance by the outward kinetic metabolic energy.
IV (f) Living organism mimics contraction-expansion phases of gravitating bodies
The overall biological growth is not a steady increase in mass or weight. An expansion is followed by a recession alternately. Biological growth consists of lag, log or exponential, senescent and steady phase i.e. period of slow, maximum, declining and stationary growth respectively. Growth period in human includes five stages viz. prenatal, infantile, early childhood, juvenile and adolescent plus post-adolescent. There is rapid growth in prenatal and puberty period. There is retarded growth in juvenile and post-adolescent periods followed by little or no growth after the post-adolescent period. Similarly in annual plants, after rapid sprouting stage, there is retardation. Growth increases slowly till mature seedling stage. After slow growth, there is another period of rapid growth up to most active tillering stage after which rate slows down again. After another period of slow growth coinciding vegetative lag-phase, the rate increases and then finally decelerates-ceasing when generative growth phase is reached. In plant, growth occurs in three steps or phases viz. formative, enlargement and differentiation. There is contraction-expansion phase in embryonic growth sequence viz. zygote and morula as contraction phase and cleavage and blastula as expansion phase in the order: zygote (shrinking phase) - cleavage (rapid rates of division) - morula (antagonism phase between periods of rapid cell division and cell movement) - blastula (cells in centre begin to lose contact with one another and a central fluid-filled cavity, the blastocel forms). If we look on the principles enumerated in the science of astrophysics, we find that this kind of inflation followed by recession in the process of growth of stellar bodies is a universal phenomenon. Even the closed model of the Universe has a contraction phase following the expansion phase.
IV(g) Logarithmic spiral formation from gravitational centre
Logarithmic spiral is known as growth spiral, equiangular spiral or spira mirabilis. Length of radius goes on increasing with shell. Logarithmic spiral has unique geometrical property of maintaining a constant angle between radius and tangent at any point on the curve from the core or centre with only length of radius goes on increasing with the growth of shell (Illustration`10). In biological world, such spiral is abundant, say, in Fibonacci numbers, golden ratio, or golden spiral in snails, snakes and others. Mechanism of potential energy of self gravity versus kinetic energy of metabolism is responsible for formation of logarithmic spirals in nature.
Illustration`10. Unique geometrical property of maintaining a constant angle between radius and tangent at any point on the curve from the core or centre with only length of radius goes on increasing with the growth of shell.
IV (h) Symmetry in morphological structure in plant and animal
My present investigation began with the quest - why all living species are in spherical symmetry? Why round? Why not square? The human body- head, hand, leg etc. are all in spherical pattern, starting journey from spherical shaped eggs/ embryo. Tips of fingers, flowers or inflorescences are all in spherical symmetries. Notion of surface tension had to be quashed. Transplanting in agricultural field two to three rice seedlings in a bunch, keeping 15-25 cm isolation between bunches, one can notice that the canopy of three seedlings coalesce and form a single top-round canopy at the end of vegetative phase or at the end of reproductive phase (Illustration 11). Why the middle one gets taller than the neighboring two on synchronization? All rice plants are of same age and same genetic constitution. Nutrient availability is also same for all plants, since they are in the same spatial zone of the soil. Bending of plants towards source of light under indoor condition or the effective spectral region triggering phototropism in between 350-500 nm i.e. the blue region of the spectrum is also not found to be beyond the threshold limit under such open field condition. Unconnected seedlings develop in orchestrated manner with common understanding that can be explained incorporating gravitational concept.
Illustration 11. Unconnected plants having homogeneous accretion, similar elements attract each other, as if they are situated within the sphere of individual’s gravity barrier. The angle between tangent and radius from common centre of gravity remains equal. Roots are denser than shoot on equal volume basis. Next phase of growth is towards root on maintaining isostatic balance (extreme right).
IV(i) Bilateral symmetry in animals
Developmental geneticists  consider cause of bilateral symmetry in animals as ‘necessity’ to cope up with environment. Similarly, if I wish to have a third eye in back, to extend my visibility in rear portion, I cannot have such extra eye or hand. Instead of wishful necessity, there should be a physical cause for every eventuality. In small mass, there is no ‘fountain effect’- only ‘central tendency’ in internal structure of living organisms. Convection is the dominant mode of energy transport in stars when the temperature gradient is steep within the star. Similarly thermal convection active in the embryo can be the driving mechanism for development of bilateral symmetry and morphogenic development in animals. During gastrulation phase of embryonic development in animals, there are ectoderm externally, the mesoderm next to this and the endoderm on the inside. Bilateral symmetry and convectional morphogenic development in animals is evident from the ‘fountain effect’ in frontal region.
IV(j) Genetic sophistication varies with mass and volume
In bacteria and blue-green algae, the nuclear material is not separated from the cytoplasm by a discrete membrane whereas it is so in majority of multicellular organisms. The entire virus consists primarily of viral genetic material enclosed in a proteinaceous envelope. Viroids, very small particles, appear to consist of genetic material alone and lack enclosing membranes. The prion which is about 100 times smaller than the smallest viruses, contain a spherical shell of protein only. Prion can reproduce in the living cell, yet no DNA or RNA has been found in them.
IV(k) Mechanical load bearing structure in cell
Mechanical living cell deformation studies have demonstrated that mechanical loads are borne by microtubules, which are balanced by tensile forces in contractile elements of the cytoskeleton. Moreover, the disruption of microtubules yields a transfer of forces to the extracellular matrix, a decrease in cell stiffness and altered cell shape. Evidence also suggests that similar forces that are active on micro-tubules are integral to the maintenance of nuclear shape and also proposes that the transfer of mechanical stress across the cytoskeleton may link the alterations in cell and nuclear shape that occur during cell spreading and retraction [22, 23]. It is interesting to note that in animal cells, the major microtubule-organizing center for bearing mechanical load is the centrosome, which is located adjacent to the nucleus near the center of interphase (non-dividing) cells. In Illustration 12, picture demonstrates mechanical load bearing structure in cell.
Illustration 12. Pictures show centralized arrangement of microtubules structure bearing mechanical loads in cell. Photo (a) taken on using green fluorescent protein (GFP) tagged proteins (photos with permission ) and under inverted colour (a’) respectively.
There are hundreds of evidences and reasoning which suggest that starting macromolecular, cellular to multi-cellular living organism, gravitational phenomena predominates in the features of living bodies. From few instance like biological growth means increase in mass; accretion mass and quantity of fluid in various stages of growth; retardation in percent increase in growth; isostatic balance in a gravitating body; balance is the Law of Life; living organism mimics contraction-expansion phases of gravitating bodies; logarithmic spiral formation from gravitational centre; symmetry in morphological structure in plants and animals; bilateral symmetry in animals; genetic sophistication varies with mass and volume; mechanical load bearing structure in cell, it is evident that these gravity centered phenomena and can be explained in single stroke. Otherwise ‘ten blind men and an elephant’ story will continue to engulf biological scenario for more centuries to come. In terms of interaction, while on earth, fluids are normally pulled down towards human feet. After ‘catapult effect’ upon entry into microgravity, inertial gravitational anchor gets withdrawn i.e. normal and hypotenuse vectors of the center of self gravity of secluded bio-matters gets pull out from inertial anchor and inverted in orthographic projection. Head ward shift of body fluids occurs. Because of limitation of space, we have avoided evidences and reasoning from current human mission in space endeavor. Incorporation of stellar findings on scaling down would ease out biological complexity.
In the light of multiple evidences and various abductive reasoning, phenomena in biological micro world could be explained on scaling down of astrophysical principles of gravitation. In such scaling down operation, the known biological elements are shown in tabular form below.