By: Wang

The term hydroponics stands for the technique of cultivating plants in a nutrient solution rather than in soil. It’s a novel technique of growing plants in water which contains dissolved nutrients. This technique is also known as indoor gardening, aquiculture and tank farming.

Studies have proved the fact that plant roots are able to absorb the nutrients from the water even without soil. The new technique hydroponics is based on the concept that plants can be grown without any soil at all.

Professor Gericke of the University of California, Davis, is considered the father of hydroponics. Professor Gericke, in 1929, proved his invention by growing tomato plants in water to a quite remarkable size. The Professor coined the name hydroponics for the culture of plants in water.

Almost any plant can be made to grow through hydroponics. Today, the new techniques of hydroponics gardening and hydroponics farming are becoming popular.
Benefits of Hydroponics:
Hydroponics is a very useful technique when there is scarcity of land, and it is growing extremely beneficial and profitable to farmers. The positive aspects of hydroponics are listed below.

Hydroponics

- Gets rid of soil-borne diseases and weeds.
- Requires no soil tilling or ploughing.
- Helpful in land scarcity; plants can be placed very close to one another.
- Can be done in small spaces.
- Highly productive; high yield, large amount of food can be produced from small spaces.
- Requires only a small amount of water compared to traditional farming.

- Allows the production of quality plants under controlled environmental conditions.

- Makes it possible to grow plants all year round.

Future of Hydroponics:

The future of hydroponics seems to be quite bright. As plants are grown indoors, they can be made to grow almost anywhere, in any condition and any weather.It’ll make it possible to grow plants in Antarctica. The techniques such as hydroponics or aeroponics may make it possible to grow vegetables and fruits in space in some near future.

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Biodiesel is a compound of methyl ester derived from the esterification/trans-esterification process of various types of vegetable oils or animal fats. Biodiesel definition has become important since many misleading definitions of biodiesel have been interpreted so as to define biodiesel as a substitute of diesel fuel from any vegetable oil without esterification/trans-esterification process.

Biodiesel production technology has referred to the reversible transesterification reaction, in which triglyceride molecule with methanol (methanolysis) is converted to alkyl methyl ester and glycerol. Although higher alcohols (ethanol) can be used in the transesterification, however, methanol is more advantageous since the two main products, fatty acid methyl ester (FAME) and glycerol, is hardly miscible and thus form separate phases – an upper ester phase and a lower glycerol phase. Moreover, the price of methanol is cheaper than ethanol which makes it preferable for commercial biodiesel production

The chemical and physical properties of biodiesel closely resemble those of diesel fuel. Biodiesel’s cetane number, energy content and viscosity are similar to those of petroleum-based diesel fuel. Biodiesel is essentially sulfur free. Engines fueled by biodiesel emit significantly fewer particulates, hydrocarbons and less carbon monoxide than that operating conventional diesel fuel.

Bio-diesel production and consumption will provide significant contribution for job creation and economic growth due to involvement of farmers and other small scale enterprises in bio-diesel value chain. Some raw material plants that can be cultivated on “marginal” soil will improve the soil environmental condition. One very important factor resulted from utilization of bio-diesel is the availability of domestic knowledge and skills to set up bio-diesel development capacity from raw materials, processing, up to distribution.

However, some challenges must be addressed to maximize the benefit of utilizing biodiesel fuel, among others, i.e. selection of most effective raw materials, sustainable raw material supply, reliable production process, bio-diesel fuel specification, pricing policy, fiscal policy, etc.

from Pilot Plant Biodiesel Puspitek Serpong BPPT

By: David H Urmann

Understanding how human growth hormones work and the possible medical benefits for using supplemental hormones for a variety of disease is a very important scientific achievement. Learn more about all the possibilities and benefits with this article.Human Growth Hormone (HGH) or Somatotrophin is a protein which helps in growth and cell production in animals and humans. It is the hormone which is made naturally in the pituitary glands of humans. The pituitary gland is deep inside the brain just behind the eye. The hormone is made in the body throughout a persons life but the development of this hormone is more when the person is young. The human growth Hormone is a microscopic protein substance and is found secreted in short pulses after the exercise and during first hours of sleep. The hormone plays a very essential role in adult metabolism and growth of children.The growth hormone as then name suggests helps in the growth of the human body. It stimulates the liver and other tissues which in turn stimulates the growth of bones. The process of growing continues till a particular time i.e the time a person reaches adult height. But the role of this particular hormone does not ends, then there will be normal level of this hormone that will maintain the balance throughout lifetime. Another function is to control protein, carbohydrate and fat metabolism, and stimulate the growth of muscle tissue in cell reproduction. Our lifestyle, diet, exercise, adequate sleep, stress levels will have great impact on it and its capacity to function properly.Normal growth and proper function will always keep the body fit but there are condition when there is excessive growth of this hormone or deficiency, both hampers the proper functioning of the body along with some adverse effects. If the level of HGH is increased in the body it results in Giantism in children where the growth is rapid and in continuation. Whereas in adults it results in Acromegaly, a disease in which the bones of the jaws, fingers and toes thickens which exerts pressure on nerves, insulin resistance or a person can suffer from a rare form of type2 diabetes. This is not all, a person with increased growth hormone can have weak muscles and reduced sexual function. This condition is treated with medication which obstructs the release of human growth hormone.When there is deficiency it results in stunted growth in children whereas the effects are mild in grown ups. They will experience muscle weakness, fatigue or weariness and inability to metabolize the fat. The deficiency can be treated with the supplements of human growth hormone. But in more severe conditions the solution lies in surgery.There are HGH injections ,HGH oral sprays and HGH supplements which are meant to fulfill the requirement when the body is not able to produce it naturally. The growth hormone are said to be working as anti aging process, but the more advanced studies reveal that the evidence are inconclusive to prove that HGH reverse the process of aging. Prolong use or regular application of growth hormone will definitely have many side effects and long lasing ill effects on health.

The adaptable nature of bacteria makes it possible to exploit particular strains for their beneficial qualities. The natural biodegradation of organic waste can be greatly enhanced by the introduction of naturally occurring, non genetically engineered, non pathogenic bacteria. Biodegrading "specialists" are scientifically selected for their exceptional enzyme production and long term stability.In the natural environment, both bacteria, and the enzymes they produce, play a significant part in biodegradation: Bacteria produce the enzymes essential for metabolizing the food source (organic waste) into energy necessary for further growth of the living organism. Enzymes facilitate the phase of metabolism in which complex compounds are broken into simpler ones (catabolism). This, in turn, speeds the process of converting the food source into an available energy supply for bacterial growth and reproduction (and continuous enzyme production).A. BACTERIA1. General BackgroundAlthough some bacteria may cause certain diseases, many more bacteria are not only harmless, but they actually are very beneficial. The positive influence of these numerous useful microscopic organisms in our biosphere is incalculable. For example, without bacteria, the soil would not be fertile (and all plants and animals ultimately are dependent upon soil fertility for life sustaining materials). Various species of bacteria are concerned in the decomposition of organic matter, fermentation, and the fixing of atmospheric nitrogen. Many of the common bacteria of air, soil and water are capable of digesting dead organic materials, proteins, carbohydrates, fats and grease, and cellulose breaking them down to simpler molecules and in utilizing these substances. This impressive ability of bacteria as a group to produce such a great diversity of biochemical changes and end results constitutes one of the outstanding facts of the natural world.2. Rate of MultiplicationGiven reasonable and suitable conditions for growth, the rate of asexual multiplication of bacteria is very rapid; it has been found that a cell divides every 20 to 30 minutes. So, assuming that conditions are conducive to a rate of one division every 30 minutes, a single individual cell will have produced 4 cells at the end of the first hour, 16 at the end of two hours, and about one million (1,000,000) at the end of fifteen (15) hours. Thus, when products containing millions of selected bacteria per milliliter are introduced under suitable conditions, the eventual bacterial growth is astronomical, and, by virtue of the presence of such great numbers of efficient, beneficial bacteria, the presence and growth of less productive and often harmful, naturally occurring bacteria are greatly reduced by competitive exclusion. Simply stated, the selected, introduced bacteria are more efficient and out compete the naturally occurring bacteria for the food source.3. Conditions Affecting Growth of Bacteriaa. Food requirements. Bacteria must obtain from their environment all nutrient materials necessary for their metabolic processes and cell reproduction. The food must be in solution and must pass into the cell.b. Temperature. For every bacterium, there 'are certain cardinal points of temperature at which growth is most rapid. Although different bacterial species differ widely, the optimum growth temperature for most bacteria lies between 5° C and 55° C (41 ° F to 131 ° F). Growth may slow at temperatures below 5°C (41 ° F) and cell damage may occur at temperatures above 60° C (140° F). The ordinary cells (non spores) are damaged at temperatures of 60° to 80° C (122° F to 140° F); hence a single boiling of a fluid or even pasteurization (application of a heat of 63° C or 145° F) is sufficient to eliminate them. Bacterial spores, however, must be subjected to very prolonged heating at higher temperatures before they are distressed.c. pH. Each bacterium has a pH range within which growth is possible. Growth will occur in environments that have pH values between 4.5 and 10; the optimum pH value differs greatly between species but an environment kept close to neutral (pH 7) will sustain most bacterial species.d. Moisture. Bacteria require moisture. The importance of moisture for bacterial growth will be seen clearly if it is realized that bacteria have no mouth parts and all their food must be absorbed in a soluble form by the process of diffusion through the cell wall; without sufficient moisture, therefore, the inflow of food and the outflow of excreta becomes impossible.e. Oxygen. Bacteria of various kinds exhibit wide differences in their relation to oxygen of the air. Some need oxygen for respiration and cannot grow unless it is provided. These are known as aerobes. Others grow only in the absence of free oxygen and are unable to use it in their respiration, they are called anaerobes. Still others can grow under either condition and are termed facultative.B. ENZYMES1. IntroductionBacteria exhibit great diversity in their physiological activities. The energy necessary for carrying on cell activity and the building materials needed for the formation of new cells during multiplication is secured in a variety of ways. The acquisition of energy and materials, in turn, is related in large measure to the different enzymes produced by various bacteria.2. Examples of Enzyme ActionMany enzymes are discharged from the cells that produce them and, therefore, function outside the living cells ("extra cellular"). For example, the secretions of the digestive tract of animals contain many such extra cellular enzymes. All of the enzymes of the digestive tract act to convert the complex molecules of food into smaller, simpler molecules which are easier to take into the bacterial cell. The process of degradation is called hydrolysis. This degradation, which involves the conversion of solids into water soluble substances, and of large water soluble molecules into smaller ones, is the essence of the process of digestion.C. SPORE FORMATIONSome bacteria are able to form spores. Spores are formed usually when conditions become unsatisfactory for active metabolism and for cell reproduction. Bacterial spores are extremely stable, and resistant to heat, drying, light, disinfectants and other harmful agents than the original vegetative bacterial organism. Spores may survive for many years.When more suitable conditions present themselves, the spore germinates and again develops a cell similar to the one that originally formed the spore. This new cell, under favorable conditions of moisture, temperature, pH and food supply, begins active metabolism, reproduction, and enzyme production.D. CONCLUSIONBacteria in nature actively compete for nutrients and the most successful species in a given habitat will be those capable of best utilizing the conditions that prevail. The introduced, specially selected, beneficial, problem solving bacteria dominate the system they are added to, and safely and economically resolve problems by eliminating the source of the problem (the organic waste is broken down, digested and metabolized). Odors are reduced by eliminating their source; and as a result, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Suspended Solids (S/S), and Volatile Fatty Acids (VFA) are reduced; and the primary byproducts of this microbial degradation are water (H20)and carbon dioxide (C02).--------------------------------------------------------------------------------BASIC DEFINITIONSAerobic Bacteria:Bacteria that require the presence of oxygen to live and function.Anaerobic Bacteria:Bacteria that do not require the presence of oxygen to survive they are capable of living and functioning in the absence of oxygen.Bacteria:Any of a group of diverse, ubiquitous, microscopic single celled microorganisms.Biochemical Oxygen Demand I(BOD):The amount of oxygen that is required/consumed by bacteria during the digestion of the organic waste in water. BOD is a relative measure of water quality since the higher the BOD, the greater the amount of organic waste in the water. Surcharges and fines are based on the BOD levels of the wastewater.Biodegradation:The digestion of organic substances by biological action, a process usually involving microbes, particularly bacteria.Chemical Oxygen Demand (COD):The amount of oxygen that is required/consumed during the digestion of organic waste by chemical means. COD is a relative measure of water quality since the higher the COD, the greater the amount of organic material in the water.Chemotaxis:The ability of an organism, in this case bacteria, to detect and move toward a particular chemical. Selected bacteria exhibit positive chemotaxis and move toward higher levels of biochemical food sources. This ability is particularly advantageous when the goal is the efficient digestion of organic materials.Colony Forming Unit I(CFU):The standard microbiological method used to count bacteria. The number of viable cells that give rise to a colony of bacteria on a suitable agar medium.Enzyme: (a/k/a non living chemical catalyst):Any of various complex organic substances originating from living microorganisms, and capable of producing certain chemical changes in organic substances by catalytic action. Enzymes are the chemical catalysts of living cells.NOTE: While bacteria metabolize a wide variety of organic material, enzymes are substrate specific. For example:Protease enzyme catabolizes ("breaks down") proteinAmylase enzyme breaks down starch and carbohydrateLipase enzyme breaks down fat and greaseXylanase enzyme breaks down plant material (xylan)Cellulase enzyme breaks down celluloseUrease enzyme breaks down ureaFacultative Bacteria:Bacteria that are capable of living and functioning either in the presence of oxygen or absence of oxygen.Microbial Degradation:The beneficial activities selected of bacteria in carrying out biodegradation.Motile:Capable of motion. Selected bacteria are motile, enabling them to move about their immediate environment.Spore:The inactive/dormant, protected/resistant form that some bacteria can temporarily assume, when conditions are not satisfactory for active metabolism and cell reproduction.Suspended Solids (SS): Particles of organic waste suspended in water. The levels of SS are often used to indicate water quality.Volatile Fatty Acids I(VFA):Volatile Fatty Acids are the compounds primarily responsible for the "sour" or "rancid" odors emanating from decaying organic material. The presence of high levels of VFA's are indicative of inefficient microbial degradation of organic waste.
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Protein crystallography plays one of the most important roles in the structural study of the different proteins. Currently in is impossible to analyze protein functionality without knowing the exact molecular structure of this particular protein. The detailed information about positions of all amino acid residues is crucially important for analysis of protein function.The protein crystallography is relatively young branch of science, which was started from studies of the DNA-double helix structure by James Watson and Francis Crick in April 1953. Currently, it is possible to solve the structure of whole virus with atomic resolution by this technique.From this time the bimolecular crystallography made great breakthrough. It was possible only due to the development of computing power of modern computers. The computational requirements of protein crystallography are enormous. For example, the structure of leucine dehydrogenase contains eight polypeptide chains, each of them contains 350 amino acids, and each of them contains about 15 atoms. So, finally we’ve got about 40 thousand atoms. For each atom we can calculate three positional and between one and nine temperature factors. Then for the simple case we need define about 160 thousand parameters, or about half-million for difficult, high resolution case. Minimization of equation with such amount of independent parameters is not very simple task. Data collection is complicated as well. Modern detectors generate about 30 Mb of raw data per few second. The storage of such informational flow is another problem for computer techniques. Luckily, last few years these computational problems were solved.Modern protein structures, solved by protein crystallography allow to identify not only the exact position of each atoms, including the position of hydrogen atoms but also detect the structural changes related with the enzymatic reactions. This will allow to investigate in great details many of the enzymatic reactions, which was previously only predicted on the basis of the catalytic amino acid residues and on the basis of the static picture of these amino acid residues. These data will be very useful in medicine, biotechnology and other field of human life. The most important is the drug design which is impossible without the knowledge of enzymatic act.Despite the great progress in protein structural studies, there are lot of protein problems which not solved yet. For example, despite the exact knowledge about structures of more than ten thousand protein structures, we do not understand the principles of protein organization and it is almost impossible to predict protein structure. The other problem is to understand the evolution of proteins. Currently we know the static picture of protein structures, but how they appear from scratch? At the moment only small ideas and examples of protein evolution are known. Another great white area in our knowledge is the protein crystallization. We can produce almost any protein by genetic techniques. After this protein purification is a quite routine procedure with the set of standard routines and procedures, but the final step, the protein crystallization is a matter of luck, rather than science. The only one thing can get the results – many trials of different crystallization conditions and maybe lucky you to grow 0.1mm protein crystal.As a conclusion it is possible to note, that despite that protein crystallography is more than 50 year old, this scientific area still have many unsolved problems and it is very interesting and perspective area of science for young biologist, chemist and physicist.

Main articles: Pseudoscience and Nonscience
Any established body of knowledge which masquerades as science in an attempt to claim a legitimacy which it would not otherwise be able to achieve on its own terms is not science; it is often known as fringe- or alternative science. The most important of its defects is usually the lack of the carefully controlled and thoughtfully interpreted experiments which provide the foundation of the natural sciences and which contribute to their advancement. Another term, junk science, is often used to describe scientific theories or data which, while perhaps legitimate in themselves, are believed to be mistakenly used to support an opposing position. There is usually an element of political or ideological bias in the used of the term. Thus the arguments in favor of limiting the use of fossil fuels in order to reduce global warming are often characterized as junk science by those who do not wish to see such restrictions imposed, and who claim that other factors may well be the cause of global warming. A wide variety of commercial advertising (ranging from hype to outright fraud) would also fall into this category. Finally, there is just plain bad science, which is commonly used to describe well-intentioned but incorrect, obsolete, incomplete, or over-simplified expositions of scientific ideas.
The status of many bodies of knowledge as true sciences, has been a matter of debate. Discussion and debate abound in this topic with some fields like the social and behavioural sciences accused by critics of being unscientific. Many groups of people from academicians like Nobel Prize physicist Percy W. Bridgman,[16] or Dick Richardson, Ph.D.—Professor of Integrative Biology at the University of Texas at Austin,[17] to politicians like U.S. Senator Kay Bailey Hutchison and other co-sponsors,[18] oppose giving their support or agreeing with the use of the label "science" in some fields of study and knowledge they consider non-scientific, ambiguous, or scientifically irrelevant compared with other fields. Karl Popper denied the existence of evidence[19] and of scientific method.[20] Popper holds that there is only one universal method, the negative method of trial and error. It covers not only all products of the human mind, including science, mathematics, philosophy, art and so on, but also the evolution of life.[21] He also contributed to the Positivism dispute, a philosophical dispute between Critical rationalism (Popper, Albert) and the Frankfurt School (Adorno, Habermas) about the methodology of the social sciences.[22]

Velocity-distribution data of a gas of rubidium atoms, confirming the discovery of a new phase of matter, the Bose–Einstein condensate.
Main article: Philosophy of science
The philosophy of science seeks to understand the nature and justification of scientific knowledge. It has proven difficult to provide a definitive account of the scientific method that can decisively serve to distinguish science from non-science. Thus there are legitimate arguments about exactly where the borders are, leading to the problem of demarcation. There is nonetheless a set of core precepts that have broad consensus among published philosophers of science and within the scientific community at large.
Science is reasoned-based analysis of sensation upon our awareness. As such, the scientific method cannot deduce anything about the realm of reality that is beyond what is observable by existing or theoretical means.[14] When a manifestation of our reality previously considered supernatural is understood in the terms of causes and consequences, it acquires a scientific explanation.[15]
Some of the findings of science can be very counter-intuitive. Atomic theory, for example, implies that a granite boulder which appears a heavy, hard, solid, grey object is actually a combination of subatomic particles with none of these properties, moving very rapidly in space where the mass is concentrated in a very small fraction of the total volume. Many of humanity's preconceived notions about the workings of the universe have been challenged by new scientific discoveries. Quantum mechanics, particularly, examines phenomena that seem to defy our most basic postulates about causality and fundamental understanding of the world around us. Science is the branch of knowledge dealing with people and the understanding we have of our environment and how it works.
There are different schools of thought in the philosophy of scientific method. Methodological naturalism maintains that scientific investigation must adhere to empirical study and independent verification as a process for properly developing and evaluating natural explanations for observable phenomena. Methodological naturalism, therefore, rejects supernatural explanations, arguments from authority and biased observational studies. Critical rationalism instead holds that unbiased observation is not possible and a demarcation between natural and supernatural explanations is arbitrary; it instead proposes falsifiability as the landmark of empirical theories and falsification as the universal empirical method. Critical rationalism argues for the ability of science to increase the scope of testable knowledge, but at the same time against its authority, by emphasizing its inherent fallibility. It proposes that science should be content with the rational elimination of errors in its theories, not in seeking for their verification (such as claiming certain or probable proof or disproof; both the proposal and falsification of a theory are only of methodological, conjectural, and tentative character in critical rationalism). Instrumentalism rejects the concept of truth and emphasizes merely the utility of theories as instruments for explaining and predicting phenomena.

Data from the famous Michelson–Morley experiment
Mathematics is essential to many sciences. One important function of mathematics in science is the role it plays in the expression of scientific models. Observing and collecting measurements, as well as hypothesizing and predicting, often require extensive use of mathematics and mathematical models. Calculus may be the branch of mathematics most often used in science[citation needed], but virtually every branch of mathematics has applications in science, including "pure" areas such as number theory and topology. Mathematics is fundamental to the understanding of the natural sciences and the social sciences, many of which also rely heavily on statistics.
Statistical methods, comprised of mathematical techniques for summarizing and exploring data, allow scientists to assess the level of reliability and the range of variation in experimental results. Statistical thinking also plays a fundamental role in many areas of science.
Computational science applies computing power to simulate real-world situations, enabling a better understanding of scientific problems than formal mathematics alone can achieve. According to the Society for Industrial and Applied Mathematics, computation is now as important as theory and experiment in advancing scientific knowledge.[13]
Whether mathematics itself is properly classified as science has been a matter of some debate. Some thinkers see mathematicians as scientists, regarding physical experiments as inessential or mathematical proofs as equivalent to experiments. Others do not see mathematics as a science, since it does not require experimental test of its theories and hypotheses. In practice, mathematical theorems and formulas are obtained by logical derivations which presume axiomatic systems, rather than a combination of empirical observation and method of reasoning that has come to be known as scientific method. In general, mathematics is classified as formal science, while natural and social sciences are classified as empirical sciences.

Main article: Scientific method

The Bohr model of the atom, like many ideas in the history of science, was at first prompted by and later partially disproved by experiment.
The scientific method seeks to explain the events of nature in a reproducible way, and to use these reproductions to make useful predictions. It is done through observation of natural phenomena, and/or through experimentation that tries to simulate natural events under controlled conditions. It provides an objective process to find solutions to problems in a number of scientific and technological fields.[6]
Based on observations of a phenomenon, a scientist may generate a model. This is an attempt to describe or depict the phenomenon in terms of a logical physical or mathematical representation. As empirical evidence is gathered, a scientist can suggest a hypothesis to explain the phenomenon. This description can be used to make predictions that are testable by experiment or observation using the scientific method. When a hypothesis proves unsatisfactory, it is either modified or discarded.
While performing experiments, Scientists may have a preference for one outcome over another, and it is important that this tendency does not bias their interpretation.[7][8] A strict following of the scientific method attempts to minimize the influence of a scientist's bias on the outcome of an experiment. This can be achieved by correct experimental design, and a thorough peer review of the experimental results as well as conclusions of a study.[9][10] Once the experiment results are announced or published, an important cross-check can be the need to validate the results by an independent party.[11]
Once a hypothesis has survived testing, it may become adopted into the framework of a scientific theory. This is a logically reasoned, self-consistent model or framework for describing the behavior of certain natural phenomena. A theory typically describes the behavior of much broader sets of phenomena than a hypothesis—commonly, a large number of hypotheses can be logically bound together by a single theory. These broader theories may be formulated using principles such as parsimony (e.g., "Occam's Razor"). They are then repeatedly tested by analyzing how the collected evidence (facts) compares to the theory. When a theory survives a sufficiently large number of empirical observations, it then becomes a scientific generalization that can be taken as fully verified. These assume the status of a physical law or law of nature.
Despite the existence of well-tested theories, science cannot claim absolute knowledge of nature or the behavior of the subject or of the field of study due to epistemological problems that are unavoidable and preclude the discovery or establishment of absolute truth. Unlike a mathematical proof, a scientific theory is empirical, and is always open to falsification, if new evidence is presented. Even the most basic and fundamental theories may turn out to be imperfect if new observations are inconsistent with them. Critical to this process is making every relevant aspect of research publicly available, which allows ongoing review and repeating of experiments and observations by multiple researchers operating independently of one another. Only by fulfilling these expectations can it be determined how reliable the experimental results are for potential use by others.
Isaac Newton's Newtonian law of gravitation is a famous example of an established law that was later found not to be universal—it does not hold in experiments involving motion at speeds close to the speed of light or in close proximity of strong gravitational fields. Outside these conditions, Newton's Laws remain an excellent model of motion and gravity. Since general relativity accounts for all the same phenomena that Newton's Laws do and more, general relativity is now regarded as a more comprehensive theory.[12

Main article: History of science
Well into the eighteenth century, science and natural philosophy were not quite synonymous, but only became so later with the direct use of what would become known formally as the scientific method, which was earlier developed during the Middle Ages and early modern period in Europe and the Middle East (see History of scientific method). Prior to the 18th century, however, the preferred term for the study of nature was natural philosophy, while English speakers most typically referred to the study of the human mind as moral philosophy. By contrast, the word "science" in English was still used in the 17th century to refer to the Aristotelian concept of knowledge which was secure enough to be used as a sure prescription for exactly how to do something. In this differing sense of the two words, the philosopher John Locke in An Essay Concerning Human Understanding wrote that "natural philosophy [the study of nature] is not capable of being made a science".[3]
By the early 1800s, natural philosophy had begun to separate from philosophy, though it often retained a very broad meaning. In many cases, science continued to stand for reliable knowledge about any topic, in the same way it is still used in the broad sense (see the introduction to this article) in modern terms such as library science, political science, and computer science. In the more narrow sense of science, as natural philosophy became linked to an expanding set of well-defined laws (beginning with Galileo's laws, Kepler's laws, and Newton's laws for motion), it became more popular to refer to natural philosophy as natural science. Over the course of the nineteenth century, moreover, there was an increased tendency to associate science with study of the natural world (that is, the non-human world). This move sometimes left the study of human thought and society (what would come to be called social science) in a linguistic limbo by the end of the century and into the next.[4]
Through the 19th century, many English speakers were increasingly differentiating science (meaning a combination of what we now term natural and biological sciences) from all other forms of knowledge in a variety of ways. The now-familiar expression “scientific method,” which refers to the prescriptive part of how to make discoveries in natural philosophy, was almost unused during the early part of the 19th century, but became widespread after the 1870s, though there was rarely totally agreement about just what it entailed.[4] The word "scientist," meant to refer to a systematically-working natural philosopher, (as opposed to an intuitive or empirically-minded one) was coined in 1833 by William Whewell.[5] Discussion of scientists as a special group of people who did science, even if their attributes were up for debate, grew in the last half of the 19th century.[4] Whatever people actually meant by these terms at first, they ultimately depicted science, in the narrow sense of the habitual use of the scientific method and the knowledge derived from it, as something deeply distinguished from all other realms of human endeavor.
By the twentieth century, the modern notion of science as a special brand of information about the world, practiced by a distinct group and pursued through a unique method, was essentially in place. It was used to give legitimacy to a variety of fields through such titles as "scientific" medicine, engineering, advertising, or motherhood.[4] Over the 1900s, links between science and technology also grew increasingly strong.

DNA determines the genetic structure of all life
The word science is derived from the Latin word scientia for knowledge, the nominal form of the verb scire, "to know". The Proto-Indo-European (PIE) root that yields scire is *skei-, meaning to "cut, separate, or discern". Other words from the same root include Sanskrit chyati, "he cuts off", Greek schizo, "I split" (hence English schism, schizophrenia), Latin scindo, "I split" (hence English rescind).[1] From the Middle Ages to the Enlightenment, science or scientia meant any systematic recorded knowledge.[2] Science therefore had the same sort of very broad meaning that philosophy had at that time. In other languages, including French, Spanish, Portuguese, and Italian, the word corresponding to science also carries this meaning.