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Thursday, August 25, 2022

Yoga (philosophy)

From Wikipedia, the free encyclopedia

Yoga philosophy is one of the six major orthodox schools of Hinduism, though it is only at the end of the first millennium CE that Yoga is mentioned as a separate school of thought in Indian texts, distinct from Samkhya. Ancient, medieval and most modern literature often refers to Yoga-philosophy simply as Yoga, A systematic collection of ideas of Yoga is found in the Yoga Sutras of Patanjali, a key text of Yoga which has influenced all other schools of Indian philosophy.

The metaphysics of Yoga is Samkhya's dualism, in which the universe is conceptualized as composed of two realities: Puruṣa (witness-consciousness) and prakriti (nature). Jiva (a living being) is considered as a state in which puruṣa is bonded to prakriti in some form, in various permutations and combinations of various elements, senses, feelings, activity and mind. During the state of imbalance or ignorance, one or more constituents overwhelm the others, creating a form of bondage. The end of this bondage is called liberation, or moksha, by both the Yoga and Samkhya schools of Hinduism, and can be attained by insight and self-restraint.

The ethical theory of Yoga-philosophy is based on Yamas and Niyama, as well as elements of the Guṇa theory of Samkhya. The epistemology of Yoga-philosophy, like the Sāmkhya school, relies on three of six Pramanas as the means of gaining reliable knowledge. These include Pratyakṣa (perception), Anumāṇa (inference) and Sabda (Āptavacana, word/testimony of reliable sources). Yoga-philosophy differs from the closely related non-theistic/atheistic Samkhya school by incorporating the concept of a "personal, yet essentially inactive, deity" or "personal god" (Ishvara).

History

Bronze figure of a Kashmiri in Meditation by Malvina Hoffman (1885-1966). The yoga posture shown is siddhasana.

Yoga-practice

The origins of yoga-practice are unclear, but seems to have developed in ascetic milieus in the first millennium BCE. Some of its earliest discussions and of proto-Samkhya ideas are found in 1st millennium BCE Indian texts such as the Katha Upanishad, the Shvetashvatara Upanishad and the Maitri Upanishad.

The root of the word "Yoga" is found in hymn 5.81.1 of the Rig Veda, a dedication to rising Sun-god in the morning (Savitri), interpreted as "yoke" or "yogically control".

युञ्जते मन उत युञ्जते धियो विप्रा विप्रस्य बृहतो विपश्चितः (…)

Seers of the vast illumined seer yogically [युञ्जते, [yunjante] control their minds and their intelligence... (…)

— Rigveda 5.81.1

The Rig Veda, however, does not describe Yoga philosophy with the same meaning or context as in medieval or modern times. Early references to practices that later became part of Yoga-philosophy, are made in Brihadaranyaka Upanishad, the oldest Upanishad. Gavin Flood translates it as, "...having become calm and concentrated, one perceives the self (atman), within oneself." The practice of pranayama (consciously regulating breath) is mentioned in hymn 1.5.23 of Brihadaranyaka Upanishad (c. ~ 900 BCE), and the practice of pratyahara (withdrawal of the senses) is mentioned in hymn 8.15 of Chandogya Upanishad (c. ~ 800-700 BCE).

The Katha Upanishad, dated to be from about the middle of the 1st millennium BCE, in verses 2.6.6 through 2.6.13 recommends a path to Self-knowledge akin to Samkhya, and calls this path Yoga.

यदा पञ्चावतिष्ठन्ते ज्ञानानि मनसा सह ।
बुद्धिश्च न विचेष्टते तामाहुः परमां गतिम् ॥ १० ॥
तां योगमिति मन्यन्ते स्थिरामिन्द्रियधारणाम् ।
अप्रमत्तस्तदा भवति योगो हि प्रभवाप्ययौ ॥ ११ ॥

Only when Manas (mind) with thoughts and the five senses stand still,
and when Buddhi (intellect, power to reason) does not waver, that they call the highest path.
That is what one calls Yoga, the stillness of the senses, concentration of the mind,
It is not thoughtless heedless sluggishness, Yoga is creation and dissolution.

— Katha Upanishad, 2.6.10-11

Yoga-practice is also mentioned in foundational texts of other orthodox schools such as the Vaisesikha Sutras, Nyaya Sutras and Brahma Sutras.

Separate darsana

Yoga as a separate school of thought is mentioned in Indian texts from the end of the 1st millennium CE. The systematic collection of ideas of the Yoga school of Hinduism is found in the Yoga Sutras of Patanjali. After its circulation in the first half of the 1st millennium CE, many Indian scholars reviewed it, then published their Bhāṣya (notes and commentary) on it, which together form a canon of texts called the Pātañjalayogaśāstra ("The Treatise on Yoga of Patañjali"). Yoga as a separate school of philosophy has been included as one of the six orthodox schools in medieval era Indian texts; the other schools are Samkhya, Nyaya, Vaisheshika, Mimamsa and Vedanta. According to Bryant,

Sāṁkhya and Yoga should not be considered different schools until a very late date: the first reference to Yoga itself as a distinct school seems to be in the writings of Śaṅkara in the 9th century C.E.

There are numerous parallels in the concepts in the Samkhya school of Hinduism, Yoga and the Abhidharma schools of thought, particularly from the 2nd century BCE to the 1st century AD, notes Larson. Patanjali's Yoga Sutras may be a synthesis of these three traditions. From the Samkhya school of Hinduism, the Yoga Sutras adopt the "reflective discernment" (adhyavasaya) of prakrti and purusa (dualism), its metaphysical rationalism, as well its three epistemic methods to gaining reliable knowledge. From Abhidharma Buddhism's idea of nirodhasamadhi, suggests Larson, the Yoga Sutras adopt the pursuit of an altered state of awareness, but unlike Buddhism, which believes that there is neither self nor soul, Yoga is physicalist and realist like Samkhya in believing that each individual has a self and soul. The third concept that the Yoga Sutras synthesize into its philosophy is the ancient ascetic traditions of isolation, meditation and introspection.

Philosophy

Yoga-philosophy is Samkhya. In both, the foundational concepts include two realities: Purusha and Prakriti. The Purusha is defined as that reality which is pure consciousness and is devoid of thoughts or qualities. The Prakriti is the empirical, phenomenal reality which includes matter and also mind, sensory organs and the sense of identity (self, soul). A living being is held in both schools to be the union of matter and mind. The Yoga school differs from the Samkhya school in its views on the ontology of Purusha, on axiology and on soteriology.

Metaphysics

The metaphysics of Yoga-Samkhya is a form of dualism. It considers consciousness and matter, self/soul and body as two different realities.

The Samkhya-Yoga system espouses dualism between consciousness and matter by postulating two "irreducible, innate and independent realities: Purusha and Prakriti. While the Prakriti is a single entity, the Samkhya-Yoga schools admit a plurality of the Puruṣas in this world. Unintelligent, unmanifest, uncaused, ever-active, imperceptible and eternal Prakriti is alone the final source of the world of objects. The Puruṣa is considered as the conscious principle, a passive enjoyer (bhokta) and the Prakriti is the enjoyed (bhogya). Samkhya-Yoga believes that the Puruṣa cannot be regarded as the source of inanimate world, because an intelligent principle cannot transform itself into the unconscious world. This metaphysics is a pluralistic spiritualism, a form of realism built on the foundation of dualism.

Yoga-philosophy adopts the theory of Guṇa from Samkhya. Guṇas theory states that three gunas (innate tendency, attributes) are present in different proportions in all beings, and these three are sattva guna (goodness, constructive, harmonious), rajas guna (passion, active, confused), and tamas guna (darkness, destructive, chaotic). These three are present in every being but in different proportions, and the fundamental nature and psychological dispositions of beings is a consequence of the relative proportion of these three gunas. When sattva guna predominates an individual, the qualities of lucidity, wisdom, constructiveness, harmonious, and peacefulness manifest themselves; when rajas is predominant, attachment, craving, passion-driven activity and restlessness manifest; and when tamas predominates in an individual, ignorance, delusion, destructive behavior, lethargy, and suffering manifests. The guṇas theory underpins the philosophy of mind in Yoga school of Hinduism.

The early scholars of Yoga philosophy, posit that the Puruṣa (consciousness) by its nature is sattva (constructive), while Prakriti (matter) by its nature is tamas (chaotic). They further posit that individuals at birth have buddhi (intelligence, sattvic). As life progresses and churns this buddhi, it creates asmita or ahamkara (ego, rajasic). When ego in turn is churned by life, manas (temper, mood, tamasic) is produced. Together, buddhi, ahamkara and manas interact and constitute citta (mind) in Yoga school of Hinduism. Unrestrained modification of citta causes suffering. A way of life that empowers one to become ever more aware of one's consciousness and spirituality innate in buddhi, is the path to one's highest potential and a more serene, content, liberated life. Patanjali's Yoga sutra begins, in verse 2 of Book 1, by defining Yoga as "restraining the Citta from Vrittis."

Soteriology

The fusion of Dharana, Dhyana and Samadhi is Sanyama – the path to Moksha or Kaivalya in Yoga school.

Yoga school of Hinduism holds that ignorance is the cause of suffering and saṁsāra. Liberation, like many other schools, is removal of ignorance, which is achieved through discriminative discernment, knowledge and self-awareness. The Yoga Sūtras is Yoga school's treatise on how to accomplish this. Samādhi is the state where ecstatic awareness develops, state Yoga scholars, and this is how one starts the process of becoming aware of Purusa and true Self. It further claims that this awareness is eternal, and once this awareness is achieved, a person cannot ever cease being aware; this is moksha, the soteriological goal in Hinduism.

Book 3 of Patanjali's Yogasutra is dedicated to soteriological aspects of yoga philosophy. Patanjali begins by stating that all limbs of yoga are necessary foundation to reaching the state of self-awareness, freedom and liberation. He refers to the three last limbs of yoga as sanyama, in verses III.4 to III.5, and calls it the technology for "discerning principle" and mastery of citta and self-knowledge. In verse III.12, the Yogasutras state that this discerning principle then empowers one to perfect sant (tranquility) and udita (reason) in one's mind and spirit, through intentness. This leads to one's ability to discern the difference between sabda (word), artha (meaning) and pratyaya (understanding), and this ability empowers one to compassionately comprehend the cry/speech of all living beings. Once a yogi reaches this state of sanyama, it leads to unusual powers, intuition, self-knowledge, freedoms and kaivalya, the soteriological goal of the yogi.

The benefits of Yoga philosophy of Hinduism is then summarized in verses III.46 to III.55 of Yogasutras, stating that the first 5 limbs leads to bodily perfections such as beauty, loveliness, strength and toughness; while the last 3 limbs through sanyama leads to mind and psychological perfections of perceptiveness, one's nature, mastery over egoism, discriminative knowledge of purity, self and soul. This knowledge once reached is irreversible, states Yogasutra's Book IV.

Ethical rules

Ethical rules in the texts of Yoga school of Hindu philosophy include both a theory of values through the observances of positive values and avoidance of negative, as well as an aesthetic theory on bliss from intrinsic and extrinsic perspectives. The values to be observed are called Niyamas, while those to be avoided are referred in the Yamas in Yoga philosophy.

Over sixty different ancient and medieval era texts of Yoga philosophy discuss Yamas and Niyamas. The specific theory and list of values varies between the texts, however, Ahimsa, Satya, Asteya, Svādhyāya, Kșhamā, and Dayā are among the predominantly discussed ethical concepts by majority of these texts.

The five yamas listed by Patañjali in Yogasūtra 2.30 are:

  1. Ahiṃsā (अहिंसा): Nonviolence, non-harming other living beings
  2. Satya (सत्य): truthfulness, non-falsehood
  3. Asteya (अस्तेय): non-stealing
  4. Brahmacarya (ब्रह्मचर्य): celibacy, non-cheating on one's partner
  5. Aparigraha (अपरिग्रहः): non-avarice, non-possessiveness

Patanjali, in Book 2, explains how and why each of the above self restraints help in the personal growth of an individual. For example, in verse II.35, Patanjali states that the virtue of nonviolence and non-injury to others (Ahimsa) leads to the abandonment of enmity, a state that leads the yogi to the perfection of inner and outer amity with everyone, everything. Other texts of the Yoga school of Hinduism include Kṣamā (क्षमा, forgiveness), Dhṛti (धृति, fortitude, non-giving up in adversity), Dayā (दया, compassion), Ārjava (आर्जव, non-hypocrisy) and Mitāhāra (मितहार, measured diet).

The Niyamas part of theory of values in the Yoga school include virtuous habits, behaviors and observances. The Yogasutra lists the niyamas as:

  1. Śauca: purity, clearness of mind, speech and body
  2. Santoṣa: contentment, acceptance of others, acceptance of one's circumstances as they are in order to get past or change them, optimism for self
  3. Tapas: persistence, perseverance, austerity
  4. Svādhyāya: study of Vedas (see Sabda in epistemology section), study of self, self-reflection, introspection of self's thoughts, speeches and actions
  5. Īśvarapraṇidhāna: contemplation of the Ishvara (God/Supreme Being, Brahman, True Self, Unchanging Reality)

As with Yamas, Patanjali explains how and why each of the above Niyamas help in the personal growth of an individual. For example, in verse II.42, Patanjali states that the virtue of contentment and acceptance of others as they are (Santoṣa) leads to the state where inner sources of joy matter most, and the craving for external sources of pleasant ceases. Other texts of the Yoga school expanded the list of values under Niyamas, to include behaviors such as Āstika (आस्तिक, belief in personal God, faith in Self, conviction that there is knowledge in Vedas/Upanishads), Dāna (दान , charity, sharing with others), Hrī (ह्री, remorse and acceptance of one's past/mistakes/ignorance, modesty) Mati (मति, think and reflect, reconcile conflicting ideas) and Vrata (व्रत, resolutions and vows, fast, pious observances).

Epistemology

The Yoga school considers perception, inference and reliable testimony as three reliable means to knowledge.

Yoga school, like Samkhya school, considers Pratyakṣa or Dṛṣṭam (direct sense perception), Anumāna (inference), and Śabda or Āptavacana (verbal testimony of the sages or shāstras) to be the only valid means of knowledge or Pramana. Unlike few other schools of Hinduism such as Advaita Vedanta, Yoga did not adopt the following three Pramanas: Upamāṇa (comparison and analogy), Arthāpatti (postulation, deriving from circumstances) or Anupalabdi (non-perception, negative/cognitive proof).

  • Pratyakṣa (प्रत्यक्षाय) means perception. It is of two types in Hindu texts: external and internal. External perception is described as that arising from the interaction of the five senses and worldly objects, while internal perception is described by this school as that of the inner sense, the mind. The ancient and medieval Indian texts identify four requirements for correct perception: Indriyarthasannikarsa (direct experience by one's sensory organ/s with the object, whatever is being studied), Avyapadesya (non-verbal; correct perception is not through hearsay, according to ancient Indian scholars, where one's sensory organ relies on accepting or rejecting someone else's perception), Avyabhicara (without wandering; correct perception is without change, nor is it the result of deception because one's sensory organ or means of observation is drifting, defective, suspect) and Vyavasayatmaka (definite; correct perception excludes judgments of doubt, either because of one's failure to observe all the details, or because one is mixing inference with observation and observing what one wants to observe, or not observing what one does not want to observe). Some ancient scholars proposed "unusual perception" as pramana and called it internal perception, a proposal contested by other Indian scholars. The internal perception concepts included pratibha (intuition), samanyalaksanapratyaksa (a form of induction from perceived specifics to a universal), and jnanalaksanapratyaksa (a form of perception of prior processes and previous states of a 'topic of study' by observing its current state). Further, some schools of Hinduism considered and refined rules of accepting uncertain knowledge from Pratyakṣa-pranama, so as to contrast nirnaya (definite judgment, conclusion) from anadhyavasaya (indefinite judgment).
  • Anumāṇa (अनुमान) means inference. It is described as reaching a new conclusion and truth from one or more observations and previous truths by applying reason. Observing smoke and inferring fire is an example of Anumana. In all except one of the Hindu philosophies, this is a valid and useful means to knowledge. The method of inference is explained by Indian texts as consisting of three parts: pratijna (hypothesis), hetu (a reason), and drshtanta (examples). The hypothesis must further be broken down into two parts, state the ancient Indian scholars: sadhya (that idea which needs to be proven or disproven) and paksha (the object on which the sadhya is predicated). The inference is conditionally true if sapaksha (positive examples as evidence) are present, and if vipaksha (negative examples as counter-evidence) are absent. For rigor, the Indian philosophies also state further epistemic steps. For example, they demand Vyapti – the requirement that the hetu (reason) must necessarily and separately account for the inference in "all" cases, in both sapaksha and vipaksha. A conditionally proven hypothesis is called a nigamana (conclusion).
  • Śabda (शब्द) means relying on word, testimony of past or present reliable experts. Hiriyanna explains Sabda-pramana as a concept which means reliable expert testimony. The schools of Hinduism which consider it epistemically valid suggest that a human being needs to know numerous facts, and with the limited time and energy available, he can learn only a fraction of those facts and truths directly. He must cooperate with others to rapidly acquire and share knowledge and thereby enrich each other's lives. This means of gaining proper knowledge is neither spoken or written, but through Sabda (sound). The reliability of the source is important, and legitimate knowledge can only come from the Sabda of reliable sources. The disagreement between the schools of Hinduism has been on how to establish reliability. Some schools, such as Carvaka, state that this is never possible, and therefore Sabda is not a proper pramana. Other schools debate means to establish reliability.

God in Yoga school of Hinduism

Yoga philosophy allows the concept of God, unlike the closely related Samkhya school of Hinduism which is atheistic/non-theistic. Hindu scholars such as the 8th century Adi Sankara, as well many modern academic scholars describe the Yoga school as "Samkya school with God."

The Yoga Sutras of Patanjali use the term Isvara in 11 verses: I.23 through I.29, II.1, II.2, II.32 and II.45. Ever since the Sutras' release, Hindu scholars have debated and commented on who or what is Isvara. These commentaries range from defining Isvara as a "personal god" to a "special self" to "anything that has spiritual significance to the individual". Whicher explains that while Patanjali's terse verses can be interpreted both as theistic or non-theistic, Patanjali's concept of Isvara in Yoga philosophy functions as a "transformative catalyst or guide for aiding the yogin on the path to spiritual emancipation".

Patanjali defines Isvara (Sanskrit: ईश्वर) in verse 24 of Book 1, as "a special Self (पुरुषविशेष, puruṣa-viśeṣa)",

Sanskrit: क्लेश कर्म विपाकाशयैःपरामृष्टः पुरुषविशेष ईश्वरः ॥२४॥
– Yoga Sutras I.24

This sutra of Yoga philosophy of Hinduism adds the characteristics of Isvara as that special Self which is unaffected (अपरामृष्ट, aparamrsta) by one's obstacles/hardships (क्लेश, klesha), one's circumstances created by the past or by one's current actions (कर्म, karma), one's life fruits (विपाक, vipâka), and one's psychological dispositions or intentions (आशय, ashaya).

Text sources

The most studied ancient and medieval era texts of the Yoga school of philosophy include those by Patanjali, Bhaskara, Haribhadra (Jain scholar), Bhoja, and Hemachandra.

References to the teachings of the Yoga school of Hinduism abound in ancient Indian texts of other orthodox schools of Hinduism, for example, verse 5.2.17 of Vaisheshika Sutra by Kanada, belonging to the Vaisheshika school of Hinduism and dated to be from the 1st millennium BCE, states

Pleasure and pain results from contact of soul, sense, mind and object. Non-origination of that follows when the mind becomes steady in the soul. After it, there is non-existence of pain in the embodied soul. This is that Yoga.

— Vaiśeṣika Sūtra 5.2.15-5.2.16

The Nyāya Sūtras by Akshapada variously dated to be from 4th to 2nd century BCE, and belonging to the Nyaya school of Hinduism, in chapter 4.2 discusses the importance of Yoga as follows,

We are instructed to practice meditation in such places as a forest, a cave or a sand-bank. Such possibilities [the opponent claims] may occur even in release. It is, we reply, not so, because knowledge must spring up only in a body already in the state of formation. And there is absence of a body in our release. For that purpose, there should be a purifying of our soul by abstinence from evil, and observance of certain virtues, as well as by following the spiritual injunctions gleaned from Yoga. To secure release [moksha], it is necessary to study and follow this treatise on knowledge [Yoga], as well as to hold discussions with those learned in that treatise.

— Nyaya Sūtra 4.2.42-4.2.47

The Brahma Sutras by Badarayana, estimated to have been completed in its surviving form in approx. 400-450 CE,  while the original version might be ancient and composed between 500 BCE and 200 BCE, belonging to the Vedanta school of Hinduism, in chapter 2 assumes the existence of a text called Yoga Smriti. Scholars contest whether this text was a precursor or the same as Patanjali's Yogasutra, but either premise is uncertain. The verses of Brahma Sutras assert that dualism of the prevailing Yoga philosophy is refuted, as the value of Yoga is as a means to realization of the Self, not in propositions about Self that is in conflict with the Vedic texts. Radhakrishnan translates the text as follows,

If it is said that there will result the defect of not allowing room for certain Smritis, we say not so, because there will result the defect of not allowing room for some other smritis [further knowledge], and on account of the non-perception of others. Thereby [pradhāna theory of] the Yoga Smriti is refuted.

— Brahma Sūtra 2.1.1-2.1.3

The Yoga Vasistha is a syncretic text on Yoga philosophy, variously dated to be from 6th- to 14th-century CE. It is structured as a dialogue between sage Vasistha of the Vedic era and the philosopher-king Rama of the Hindu epic Ramayana. The text synthesizes elements of Vedanta, Jainism, Yoga, Samkhya, Saiva Siddhanta and Mahayana Buddhism. Among other things, the text discusses Yoga philosophy in its various chapters. In section 6.1, Yoga Vasistha introduces Yoga as follows,

Yoga is the utter transcendence of the mind and is of two types. Self-knowledge is one type, another is the restraint of the life-force of self limitations and psychological conditioning. Yoga has come to mean only the latter, yet both the methods lead to the same result. To some, Self-knowledge through inquiry is difficult, to others Yoga is difficult. But my conviction is that the path of inquiry is easy for all, because Self-knowledge is the ever-present truth. I shall now describe to you the method of Yoga.

— Vasistha to Rama, Yoga Vasistha 6.1.12-13

Molecular biology

From Wikipedia, the free encyclopedia

Molecular biology /məˈlɛkjʊlər/ is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including molecular synthesis, modification, mechanisms, and interactions. The study of chemical and physical structure of biological macromolecules is known as molecular biology.

Molecular biology was first described as an approach focused on the underpinnings of biological phenomena - uncovering the structures of biological molecules as well as their interactions, and how these interactions explain observations of classical biology.

In 1945 the term molecular biology was used by physicist William Astbury. The development in the field of molecular biology happened very late as to understand that the complex system or advantageous approach would be made in simple way of understanding by using bacteria and bacteriophages this organism yields information about basic biological process more readily than animal cell. In 1953 then two young men named Francis Crick and James Watson working at Medical Research Council unit, Cavendish laboratory, Cambridge (now the MRC Laboratory of Molecular Biology), made a double helix model of DNA which changed the whole research scenario they proposed the DNA structure based on previous research done by Rosalind Franklin and Maurice Wilkins then the research lead to finding DNA material in other microorganisms, plants and animals.

Molecular biology is not simply the study of biological molecules and their interactions; rather, it is also collection of techniques developed since the field's genesis which have enabled scientists to learn about molecular processes. One notable technique which has revolutionized the field is the polymerase chain reaction (PCR), which was developed in 1983. PCR is a reaction which amplifies small quantities of DNA, and it is used in many applications across scientific disciplines, as will be discussed later.

The central dogma of molecular biology describes the process in which DNA is transcribed into RNA, which is then translated into protein.

Molecular biology also plays a critical role in the understanding of structures, functions, and internal controls within individual cells, all of which can be used to efficiently target new drugs, diagnose disease, and better understand cell physiology. Some clinical research and medical therapies arising from molecular biology are covered under gene therapy whereas the use of molecular biology or molecular cell biology in medicine is now referred to as molecular medicine.

History of molecular biology

Molecular biology sits at the intersection of biochemistry and genetics; as these scientific disciplines emerged and evolved in the 20th century, it became clear that they both sought to determine the molecular mechanisms which underlie vital cellular functions. Advances in molecular biology have been closely related to the development of new technologies and their optimization. Molecular biology has been elucidated by the work of many scientists, and thus the history of the field depends on an understanding of these scientists and their experiments.

It all begins with the phenomenon of transformation in the bacteria,  in 1928, Frederick Griffith, observed a phenomenon of transformation from one bacterium to other [now known as genetic transformation]. At that time, he couldn't explain the phenomenon of transformation. Later in 1944, three scientists Oswald Avery, Colin Macleod and Maclyn McCarty, demonstrated the whole phenomenon of transformation in the bacteria. After, two years in 1930, molecular biology was established as an official branch of science. But the term “Molecular Biology” wasn't coined until 1938 and that was done by the scientist Warren Weaver, who was working as the director of Natural sciences at Rockefeller Foundation.

From the following experiment it was concluded that DNA is the basic genetic material which caused the genetic changes. Basic composition of the DNA was known that it contains four bases known as – Adenine, Guanine, Thymine and Cytosine. So, on the bases of the chemical composition and the X-ray crystallography, done by Maurice Wilkins and Rosalind Franklin the DNA structure was proposed by James Watson and Francis Crick. But, before the Watson and Crick proposed the DNA structure, in 1950 Austrian born scientist Erwin Chargaff, proposed the theory / rule [today known as- Chargaff's rule], which stated that the number of Adenine and Thymine and Guanine and Cytosine are in equal proportion.

The Chargaff's rule

"Chargaff's rule stated that DNA from any species of any organism should have a 1:1 stoichiometric ratio of purine and pyrimidines (i.e., A+G=T+C) and, more specifically, that the amount of guanine should be equal to cytosine and the amount of adenine should be equal to thymine. This pattern is found in both strands of the DNA".

The field of genetics arose as an attempt to understand the molecular mechanisms of genetic inheritance and the structure of a gene. Gregor Mendel pioneered this work in 1866, when he first wrote the laws of genetic inheritance based on his studies of mating crosses in pea plants. One such law of genetic inheritance is the law of segregation, which states that diploid individuals with two alleles for a particular gene will pass one of these alleles to their offspring. Because of his critical work, the study of genetic inheritance is commonly referred to as Mendelian genetics.

A major milestone in molecular biology was the discovery of the structure of DNA. This work began in 1869 by Friedrich Miescher, a Swiss biochemist who first proposed a structure called nuclein, which we now know to be deoxyribonucleic acid, or DNA. He discovered this unique substance by studying the components of pus-filled bandages, and noting the unique properties of the "phosphorus-containing substances". Another notable contributor to the DNA model was Phoebus Levene, who proposed the "polynucleotide model" of DNA in 1919 as a result of his biochemical experiments on yeast. In 1950, Erwin Chargaff expanded on the work of Levene and elucidated a few critical properties of nucleic acids: first, the sequence of nucleic acids varies across species. Second, the total concentration of purines (adenine and guanine) is always equal to the total concentration of pyrimidines (cysteine and thymine). This is now known as Chargaff's rule. In 1953, James Watson and Francis Crick published the double helical structure of DNA, using the X-ray crystallography work done by Rosalind Franklin and Maurice Wilkins. Watson and Crick described the structure of DNA and conjectured about the implications of this unique structure for possible mechanisms of DNA replication.

J. D. Watson and F. H. C. Crick were awarded Nobel prize in 1962, along with Maurice Wilkens, for proposing a model of the structure of DNA.

As time pass by, in 1964 K. A. Marcker and Frederick Sanger discovered a peculiar amioacyl-tRNA in E.coli, called N-formyl- methionyl – tRNA and explained that this molecule play a role in special mechanism of the chain elongation. He was awarded second Nobel prize for discovering complete sequence of 5,400 nucleotides of single stranded DNA of F ´ 174 bacteriophages.

In 1961, it was demonstrated that when a gene encodes a protein, three sequential bases of a gene's DNA specify each successive amino acid of the protein. Thus the genetic code is a triplet code, where each triplet (called a codon) specifies a particular amino acid. Furthermore, it was shown that the codons do not overlap with each other in the DNA sequence encoding a protein, and that each sequence is read from a fixed starting point.

During 1962–1964, through the use of conditional lethal mutants of a bacterial virus, fundamental advances were made in our understanding of the functions and interactions of the proteins employed in the machinery of DNA replication, DNA repair, DNA recombination, and in the assembly of molecular structures.

Diagrammatic representation of Watson and Crick's DNA structure
 
Angle description in DNA structure

The F.Griffith experiment

Diagrammatic representation of experiment
 

In 1928, Fredrick Griffith, encountered a virulence property in pneumococcus bacteria, which was killing lab rats. According to Mendel, prevalent at that time, gene transfer could occur only from parent to daughter cells only. Griffith advanced another theory, stating that gene transfer occurring in member of same generation is known as horizontal gene transfer (HGT). This phenomenon is now referred to as genetic transformation.

Griffith addressed the Streptococcus pneumoniae bacteria, which had two different strains, one virulent and smooth and one avirulent and rough. The smooth strain had glistering appearance owing to the presence of a type of specific polysaccharide – a polymer of glucose and glucuronic acid capsule. Due to this polysaccharide layer of bacteria, a host's immune system cannot recognize the bacteria and it kills the host. The other, avirulent, rough strain lacks this polysaccharide capsule and has a dull, rough appearance.

Presence or absence of capsule in the  strain, is known to be genetically determined. Smooth and rough strains occur in several different type such as S-I, S-II, S-III, etc. and R-I, R-II, R-III, etc. respectively. All this subtypes of S and R bacteria differ with each other in antigen type they produce.

Hershey and Chase experiment

Hershey and Chase experiment

Confirmation that DNA is the genetic material which is cause of infection came from Hershey and Chase experiment. They used E.coli and bacteriophage for the experiment. This experiment is also known as blender experiment, as kitchen blender was used as a major piece of apparatus. Alfred Hershey and Martha Chase demonstrated that the DNA injected by a phage particle into a bacterium contains all information required to synthesize progeny phage particles. They used radioactivity to tag the bacteriophage's protein coat with radioactive sulphur and DNA with radioactive phosphorus, into two different test tubes respectively. After mixing bacteriophage and E.coli into the test tube, the incubation period starts in which phage transforms the genetic material in the E.coli cells. Then the mixture is blended or agitated, which separates the phage from E.coli cells. The whole mixture is centrifuged and the pellet which contains E.coli cells was checked and the supernatant was discarded. The E.coli cells showed radioactive phosphorus, which indicated that the transformed material was DNA not the protein coat.

The transformed DNA gets attached to the DNA of E.coli and radioactivity is only seen onto the bacteriophage's DNA. This mutated DNA can be passed to the next generation and the theory of Transduction came into existence. Transduction is a process in which the bacterial DNA carry the fragment of bacteriophages and pass it on the next generation. This is also a type of horizontal gene transfer.

Modern molecular biology

In the mid-2020s, molecular biology entered a golden age defined by both vertical and horizontal technical development. Vertically, novel technologies are allowing for real-time monitoring of biological processes at the atomic level. Molecular biologists today have access to increasingly affordable sequencing data at increasingly higher depths, facilitating the development of novel genetic manipulation methods in new non-model organisms. Likewise, synthetic molecular biologists will drive the industrial production of small and macro molecules through the introduction of exogenous metabolic pathways in various prokaryotic and eukaryotic cell lines.

Horizontally, sequencing data is becoming more affordable and utilized in many different scientific fields. This will drive the development of industries in developing nations and increase accessibility to individual researchers. Likewise, CRISPR-Cas9 gene editing experiments can now be conceived and implemented by individuals for under $10,000 in novel organisms, which will drive the development of industrial and medical applications 

Relationship to other biological sciences

Schematic relationship between biochemistry, genetics and molecular biology

The following list describes a viewpoint on the interdisciplinary relationships between molecular biology and other related fields.

While researchers practice techniques specific to molecular biology, it is common to combine these with methods from genetics and biochemistry. Much of molecular biology is quantitative, and recently a significant amount of work has been done using computer science techniques such as bioinformatics and computational biology. Molecular genetics, the study of gene structure and function, has been among the most prominent sub-fields of molecular biology since the early 2000s. Other branches of biology are informed by molecular biology, by either directly studying the interactions of molecules in their own right such as in cell biology and developmental biology, or indirectly, where molecular techniques are used to infer historical attributes of populations or species, as in fields in evolutionary biology such as population genetics and phylogenetics. There is also a long tradition of studying biomolecules "from the ground up", or molecularly, in biophysics.

Techniques of molecular biology

DNA animation
 

Molecular cloning

Transduction image

Molecular cloning is used to isolate and then transfer a DNA sequence of interest into a plasmid vector. This recombinant DNA technology was first developed in the 1960s. In this technique, a DNA sequence coding for a protein of interest is cloned using polymerase chain reaction (PCR), and/or restriction enzymes, into a plasmid (expression vector). The plasmid vector usually has at least 3 distinctive features: an origin of replication, a multiple cloning site (MCS), and a selective marker (usually antibiotic resistance). Additionally, upstream of the MCS are the promoter regions and the transcription start site, which regulate the expression of cloned gene.

This plasmid can be inserted into either bacterial or animal cells. Introducing DNA into bacterial cells can be done by transformation via uptake of naked DNA, conjugation via cell-cell contact or by transduction via viral vector. Introducing DNA into eukaryotic cells, such as animal cells, by physical or chemical means is called transfection. Several different transfection techniques are available, such as calcium phosphate transfection, electroporation, microinjection and liposome transfection. The plasmid may be integrated into the genome, resulting in a stable transfection, or may remain independent of the genome and expressed temporarily, called a transient transfection.

DNA coding for a protein of interest is now inside a cell, and the protein can now be expressed. A variety of systems, such as inducible promoters and specific cell-signaling factors, are available to help express the protein of interest at high levels. Large quantities of a protein can then be extracted from the bacterial or eukaryotic cell. The protein can be tested for enzymatic activity under a variety of situations, the protein may be crystallized so its tertiary structure can be studied, or, in the pharmaceutical industry, the activity of new drugs against the protein can be studied.

Polymerase chain reaction

Polymerase chain reaction (PCR) is an extremely versatile technique for copying DNA. In brief, PCR allows a specific DNA sequence to be copied or modified in predetermined ways. The reaction is extremely powerful and under perfect conditions could amplify one DNA molecule to become 1.07 billion molecules in less than two hours. PCR has many applications, including the study of gene expression, the detection of pathogenic microorganisms, the detection of genetic mutations, and the introduction of mutations to DNA. The PCR technique can be used to introduce restriction enzyme sites to ends of DNA molecules, or to mutate particular bases of DNA, the latter is a method referred to as site-directed mutagenesis. PCR can also be used to determine whether a particular DNA fragment is found in a cDNA library. PCR has many variations, like reverse transcription PCR (RT-PCR) for amplification of RNA, and, more recently, quantitative PCR which allow for quantitative measurement of DNA or RNA molecules.

Two percent agarose gel in borate buffer cast in a gel tray.

Gel electrophoresis

SDS-PAGE
 

Gel electrophoresis is a technique which separates molecules by their size using an agarose or polyacrylamide gel. This technique is one of the principal tools of molecular biology. The basic principle is that DNA fragments can be separated by applying an electric current across the gel - because the DNA backbone contains negatively charged phosphate groups, the DNA will migrate through the agarose gel towards the positive end of the current. Proteins can also be separated on the basis of size using an SDS-PAGE gel, or on the basis of size and their electric charge by using what is known as a 2D gel electrophoresis.

Proteins stained on a PAGE gel using Coomassie blue dye.

The Bradford Assay

The Bradford Assay is a molecular biology technique which enables the fast, accurate quantitation of protein molecules utilizing the unique properties of a dye called Coomassie Brilliant Blue G-250. Coomassie Blue undergoes a visible color shift from reddish-brown to bright blue upon binding to protein. In its unstable, cationic state, Coomassie Blue has a background wavelength of 465 nm and gives off a reddish-brown color. When Coomassie Blue binds to protein in an acidic solution, the background wavelength shifts to 595 nm and the dye gives off a bright blue color. Proteins in the assay bind Coomassie blue in about 2 minutes, and the protein-dye complex is stable for about an hour, although it's recommended that absorbance readings are taken within 5 to 20 minutes of reaction initiation. The concentration of protein in the Bradford assay can then be measured using a visible light spectrophotometer, and therefore does not require extensive equipment.

This method was developed in 1975 by Marion M. Bradford, and has enabled significantly faster, more accurate protein quantitation compared to previous methods: the Lowry procedure and the biuret assay.[40] Unlike the previous methods, the Bradford assay is not susceptible to interference by several non-protein molecules, including ethanol, sodium chloride, and magnesium chloride.  However, it is susceptible to influence by strong alkaline buffering agents, such as sodium dodecyl sulfate (SDS).

Macromolecule blotting and probing

The terms northern, western and eastern blotting are derived from what initially was a molecular biology joke that played on the term Southern blotting, after the technique described by Edwin Southern for the hybridisation of blotted DNA. Patricia Thomas, developer of the RNA blot which then became known as the northern blot, actually didn't use the term.

Southern blotting

Named after its inventor, biologist Edwin Southern, the Southern blot is a method for probing for the presence of a specific DNA sequence within a DNA sample. DNA samples before or after restriction enzyme (restriction endonuclease) digestion are separated by gel electrophoresis and then transferred to a membrane by blotting via capillary action. The membrane is then exposed to a labeled DNA probe that has a complement base sequence to the sequence on the DNA of interest. Southern blotting is less commonly used in laboratory science due to the capacity of other techniques, such as PCR, to detect specific DNA sequences from DNA samples. These blots are still used for some applications, however, such as measuring transgene copy number in transgenic mice or in the engineering of gene knockout embryonic stem cell lines.

Northern blotting

Northern blot diagram

The northern blot is used to study the presence of specific RNA molecules as relative comparison among a set of different samples of RNA. It is essentially a combination of denaturing RNA gel electrophoresis, and a blot. In this process RNA is separated based on size and is then transferred to a membrane that is then probed with a labeled complement of a sequence of interest. The results may be visualized through a variety of ways depending on the label used; however, most result in the revelation of bands representing the sizes of the RNA detected in sample. The intensity of these bands is related to the amount of the target RNA in the samples analyzed. The procedure is commonly used to study when and how much gene expression is occurring by measuring how much of that RNA is present in different samples, assuming that no post-transcriptional regulation occurs and that the levels of mRNA reflect proportional levels of the corresponding protein being produced. It is one of the most basic tools for determining at what time, and under what conditions, certain genes are expressed in living tissues.

Western blotting

A western blot is a technique by which specific proteins can be detected from a mixture of proteins. Western blots can be used to determine the size of isolated proteins, as well as to quantify their expression. In western blotting, proteins are first separated by size, in a thin gel sandwiched between two glass plates in a technique known as SDS-PAGE. The proteins in the gel are then transferred to a polyvinylidene fluoride (PVDF), nitrocellulose, nylon, or other support membrane. This membrane can then be probed with solutions of antibodies. Antibodies that specifically bind to the protein of interest can then be visualized by a variety of techniques, including colored products, chemiluminescence, or autoradiography. Often, the antibodies are labeled with enzymes. When a chemiluminescent substrate is exposed to the enzyme it allows detection. Using western blotting techniques allows not only detection but also quantitative analysis. Analogous methods to western blotting can be used to directly stain specific proteins in live cells or tissue sections.

Eastern blotting

The eastern blotting technique is used to detect post-translational modification of proteins. Proteins blotted on to the PVDF or nitrocellulose membrane are probed for modifications using specific substrates.

Microarrays

Hybridization of target to probe

A DNA microarray is a collection of spots attached to a solid support such as a microscope slide where each spot contains one or more single-stranded DNA oligonucleotide fragments. Arrays make it possible to put down large quantities of very small (100 micrometre diameter) spots on a single slide. Each spot has a DNA fragment molecule that is complementary to a single DNA sequence. A variation of this technique allows the gene expression of an organism at a particular stage in development to be qualified (expression profiling). In this technique the RNA in a tissue is isolated and converted to labeled complementary DNA (cDNA). This cDNA is then hybridized to the fragments on the array and visualization of the hybridization can be done. Since multiple arrays can be made with exactly the same position of fragments, they are particularly useful for comparing the gene expression of two different tissues, such as a healthy and cancerous tissue. Also, one can measure what genes are expressed and how that expression changes with time or with other factors. There are many different ways to fabricate microarrays; the most common are silicon chips, microscope slides with spots of ~100 micrometre diameter, custom arrays, and arrays with larger spots on porous membranes (macroarrays). There can be anywhere from 100 spots to more than 10,000 on a given array. Arrays can also be made with molecules other than DNA.

Allele-specific oligonucleotide

Allele-specific oligonucleotide (ASO) is a technique that allows detection of single base mutations without the need for PCR or gel electrophoresis. Short (20–25 nucleotides in length), labeled probes are exposed to the non-fragmented target DNA, hybridization occurs with high specificity due to the short length of the probes and even a single base change will hinder hybridization. The target DNA is then washed and the labeled probes that didn't hybridize are removed. The target DNA is then analyzed for the presence of the probe via radioactivity or fluorescence. In this experiment, as in most molecular biology techniques, a control must be used to ensure successful experimentation.

In molecular biology, procedures and technologies are continually being developed and older technologies abandoned. For example, before the advent of DNA gel electrophoresis (agarose or polyacrylamide), the size of DNA molecules was typically determined by rate sedimentation in sucrose gradients, a slow and labor-intensive technique requiring expensive instrumentation; prior to sucrose gradients, viscometry was used. Aside from their historical interest, it is often worth knowing about older technology, as it is occasionally useful to solve another new problem for which the newer technique is inappropriate.

Green hydrogen

From Wikipedia, the free encyclopedia

Green hydrogen is hydrogen generated by renewable energy or from low-carbon power. Green hydrogen has significantly lower carbon emissions than grey hydrogen, which is produced by steam reforming of natural gas, which makes up the bulk of the hydrogen market. Green hydrogen produced by the electrolysis of water is less than 0.1% of total hydrogen production. It may be used to decarbonize sectors which are hard to electrify, such as steel and cement production, and thus help to limit climate change.

The high cost of production is the main factor behind the low use of green hydrogen. Nonetheless, the hydrogen market is expected to grow, with some forecasts of the cost of hydrogen production falling from $6/kg in 2015 to around $2/kg by 2025. In 2020, major European companies announced plans to switch their truck fleets to hydrogen power.

Green hydrogen can be blended into existing natural gas pipelines, and also used to produce green ammonia, the main constituent of fertilizer production. It is suggested by hydrogen industry bodies that green ammonia will be cost-competitive with ammonia produced conventionally (gray ammonia) by 2030.

Definition

Green hydrogen is produced by using renewable energy to power the electrolysis of water.

Certified green hydrogen requires an emission reduction of >60-70% (depending on the certification body) below the benchmark emissions intensity threshold (= GHG emissions of grey hydrogen, for example benchmark values according to the renewable energy directive RED II).

Market

The high cost of production is the main factor behind the low use of green hydrogen. Nonetheless, the United States Department of Energy forecasts that the hydrogen market is expected to grow, with the cost of hydrogen production falling from $6/kg in 2015 to as low as $2/kg by 2025. The price of $2/kg is considered a potential tipping point that will make green hydrogen competitive against other fuel sources. Siemens has already developed offshore wind turbines which are equipped for a hydrogen blend and, consequently help increase production of green hydrogen.

The majority of hydrogen produced globally in 2020 is derived from fossil fuel sources with 99% of hydrogen fuel coming from carbon-based sources, and is not green hydrogen.

Green hydrogen has significantly lower carbon emissions than grey hydrogen, which is produced by steam reforming of natural gas and represents 95% of the market. On the contrary, green hydrogen, specifically, that produced by electrolysis of water represents less than 0.1% of total hydrogen production.

Uses

According to BloombergNEF, ". . . hydrogen offers the greatest potential to decarbonize difficult-to-abate sectors like steel, cement and heavy duty transport." Green hydrogen has been used in transportation, heating, and in the natural gas industry, and can be used to produce green ammonia.

Transportation

Hydrogen can be used as a hydrogen fuel for fuel cells or internal combustion engines. Hydrogen vehicles are not limited to automobiles, with trucks also being designed to run on green hydrogen. In 2020, major European companies announced plans to switch their truck fleets to hydrogen power. Additionally, hydrogen-powered aircraft are already being designed by Airbus, with a planned release of the first commercial aircraft by 2035. Nevertheless, Airbus has warned that hydrogen will not be widely used on aircraft before 2050.

Heating

Hydrogen can be used for cooking and heating within homes. Hydrogen heating has been proposed as an alternative to power most UK homes by 2050. The British government intends to launch demonstration projects to show how the fuel can power regions containing hundreds of homes.

Natural gas industry

Natural gas pipelines are sometimes used to transport hydrogen, but it is not without challenges. Many pipelines would need to be upgraded for hydrogen transport. The natural gas industry and its infrastructure could pose a roadblock to green hydrogen adoption for countries that intend to be carbon neutral. A pilot program in Cappelle-la-Grande‚ France has already mixed hydrogen into the gas grid of 100 homes. Natural gas-fired power plants can also be converted to burn hydrogen serving to provide backup power during periods of high demand.

Green ammonia production

Green hydrogen can be used to produce green ammonia, the main constituent of fertilizer production. The Hydrogen Council suggested in 2021 that green ammonia will be cost competitive with ammonia produced conventionally (gray ammonia) by 2030.

Economy

As of 2020, the global hydrogen market was valued at $900 million and expected to reach $300 billion by 2050. According to analysts at Fitch Solutions, the global hydrogen market could jump to 10% by 2030. The number of investments in green hydrogen has risen from almost none in 2020 to 121 gigawatts across 136 projects in planning and development phases totaling over $500 billion in 2021. Companies across countries have formed alliances to increase production of the fuel fiftyfold in the next six years. The market could be worth over $1 trillion a year by 2050 according to Goldman Sachs.

Africa

Mauritania has launched two major projects on green hydrogen: NOUR Project, one of the world’s largest hydrogen projects with 10 GW of capacity by 2030 in cooperation with Chariot company. The second is EMAN Project, which include 18GW of wind capacity and 12GW of solar capacity to produce 1.7 million tons per annum of green hydrogen or 10 million tons per annum of green ammonia for local use and export, in cooperation with Australian company CWP. Countries in Africa such as Morocco, Tunisia, Egypt and Namibia have proposed plans to have green hydrogen as a part of their overall climate change goals. Namibia is already partnering with European countries such as Netherlands and Germany for feasibility studies and funding.

Australia

In Australia, green hydrogen has cost twice as much as conventional hydrogen and blue hydrogen, but a 2020 Australian National University report estimated that Australia could be producing it for much cheaper, even currently, and it could equal the price of conventional and blue hydrogen (at about A$2 per kilogram) by 2030, which would be cost-competitive with fossil fuels. An energy market analyst suggested in early 2021 that the price of green hydrogen would drop 70% over the coming 10 years in countries which have cheap renewable energy. In 2020, the government fast tracked approval for the world's largest planned renewable energy export facility in the Pilbara region. The following year, energy companies announced plans to construct a "hydrogen valley" in New South Wales at a cost of $2 billion which would replace the region's coal industry.

As of July 2022, the Australian Renewable Energy Agency (ARENA) has invested $88 million in 35 hydrogen projects ranging from research and development projects with universities, to first-of-a-kind demonstrations. In 2022, ARENA expects to reach financial close on two or three of Australia’s first large-scale electrolyser deployments as part of its $100 million hydrogen deployment round.

Asia

China

China is the leader of the global hydrogen market with an output of 20 million tons, accounting for ⅓ of global production. Sinopec aims to generate 500,000 tonnes of green hydrogen by 2025. Researchers from the Harvard China Project have indicated that hydrogen generated from wind energy could provide a cost effective alternative for coal-dependent regions like Inner Mongolia. As part of preparations for the 2022 Winter Olympics a hydrogen electrolyzer, described as the "world's largest" began operations to provide fuel for vehicles used at the games. The electrolyzer produced green hydrogen using onshore wind.

Japan

In order to become carbon neutral, the Japanese government intends to transform the nation into a "hydrogen society". The energy demand in Japan would require the government to import 36 million tons of liquefied hydrogen. The nation's commercial imports are projected to be 100 times less than this amount by 2030, when the use of the fuel is expected to commence, which represents a serious challenge. Japan has published a preliminary road map that called for hydrogen and related fuels to supply 10% of the power for electricity generation as well as a significant portion of the energy for other uses like shipping and steel manufacture by 2050. The country has created a hydrogen highway consisting of 135 subsidized hydrogen fuels stations and plans to construct 1,000 by the end of the decade.

Oman

A consortium of companies have announced a $30 billion project in Oman which would become one of the largest hydrogen facilities in the world. Construction will begin in 2028 and by 2038 the project will be powered by 25 GW of wind and solar energy.

United Arab Emirates

In 2021, in collaboration with Expo 2020 Dubai a pilot project was launched which is the first "industrial scale", solar-driven green hydrogen facility in the Middle East and North Africa."

Saudi Arabia

In 2021, Saudi Arabia, as a part of the NEOM project, announced an investment of $5bn to build a green hydrogen-based ammonia plant, which would start production from 2025.

India

Reliance Industries Limited and Adani Group - two of India's largest Energy companies announced foray in green hydrogen production in 2021. Reliance Industries announced its plan to use about 3 gigawatt (GW) of solar energy to generate 400,000 tonnes of hydrogen. Gautam Adani, Founder of Adani Group too announced plans to invest $70 billion to become the world's largest renewable energy company and produce the cheapest hydrogen across the globe. The power ministry of India has stated the country intends to produce a cumulative 5 million tonnes of green hydrogen by 2030.

On April 20, 2022, the public sector Oil India Limited (OIL), which is headquartered in eastern Assam’s Duliajan, set up India’s first 99.99% pure green hydrogen pilot plant in keeping with the goal of “making the country ready for the pilot-scale production of hydrogen and its use in various applications” while “research and development efforts are ongoing for a reduction in the cost of production, storage and the transportation” of hydrogen.

South Korea

In October 2020, the South Korean government announced its plan to introduce the Clean Hydrogen Energy Portfolio Standards (CHPS) that emphasizes the use of clean hydrogen. During the introduction of the Hydrogen Energy Portfolio Standard (HPS), it voted by the 2nd Hydrogen Economy Committee. In addition, in March 2021, the 3rd Hydrogen Economy Committee was held to pass a plan to introduce a clean hydrogen certification system based on incentives and obligations for clean hydrogen.

In June 2021, Hyundai Engineering signed a mutual business agreement with POSCO, Gyeongsangbuk-do, Uljin-gun, Pohang University, Pohang Institute of Industrial Science and the Korea Atomic Energy Research Institute. It plans to secure MMR technology competitiveness and revitalize the hydrogen economy through cooperation such as developing hot hydrogen production technology, developing hot water electrolytic technology, and commercializing nuclear power.

European Union

In July 2020 the European Union unveiled the Hydrogen Strategy for a Climate-Neutral Europe with the goal of reaching carbon neutrality by incorporating hydrogen into the EU plans. A motion backing this strategy passed the European Parliament the next year. The plan will be divided in three phases. The first one, from 2020 to 2024, will aim at decarbonizing all existing hydrogen production. The second phase (2024-2030) will integrate green hydrogen into the energy system. The third phase (2030 to 2050) will see a large-scale deployment of hydrogen in the decarbonization process. Goldman Sachs estimates hydrogen will be 15% of the EU energy mix by 2050. Six European Union member states: Germany, Austria, France, the Netherlands, Belgium and Luxembourg, requested hydrogen funding be backed by legislation. Germany has already invested €9 billion to construct 5 GW of hydrogen capacity by 2030. Many member countries have created plans to import hydrogen from other nations, especially from North Africa. These plans would increase hydrogen production, however they have also been accused of trying to export the necessary changes needed within Europe. The European Union has required that starting 2021 all new gas turbines made in the bloc must be equipped ready to burn a hydrogen–natural gas blend.

In February 2021, thirty companies announced a pioneering project to provide hydrogen based in Spain. The project intends to start in 2022, creating 93 GW of solar and 67 GW of electrolysis capacity by the end of the decade. In April 2021, Portugal announced plans to construct the first solar-powered plant to produce hydrogen by 2023. Lisbon based energy company Galp Energia has also announced plans to construct an electrolyzer to power its refinery by 2025.

Latin America

In November 2020 Chile's president presented the "National Strategy for Green Hydrogen," stating he wanted Chile to become "the most efficient green hydrogen producer in the world by 2030". The plan includes HyEx, a project to make solar based hydrogen for use in the mining industry.

United Kingdom

In 2021, the British government published its policy document, a "Ten Point Plan for a Green Industrial Revolution," which included investing to create 5 GW of low carbon hydrogen by 2030. The plans include work with the industry to complete the necessary testing that would allow up to 20% blending of hydrogen into the gas distribution grid for all homes on the gas grid by 2023. One offshore wind proposal in Scotland includes plans to convert oil and gas rigs into a "green hydrogen hub" which would supply fuel to local distilleries. In June 2021 Equinor announced plans to triple UK hydrogen production. In March 2022 National Grid announced a project to introduce green hydrogen into the grid with a 200m wind turbine powering an electrolyzer to produce gas for about 300 homes.

United States

During his 2003 State of the Union address, President George W. Bush unveiled a $1.2 billion plan to develop hydrogen fuel cell vehicles dubbing it "freedom fuel." This funding was reduced in 2009 by Barack Obama.

In June 2021, Energy Secretary Jennifer Granholm announced plans in line with the Biden administration's pledge of cutting the cost of green hydrogen production. In 2021, the U.S. Department of Energy (DOE) was planning the first demonstration of a hydrogen network in Texas. The department had previously attempted a hydrogen project known as Hydrogen Energy California. Texas is considered a key part of green hydrogen projects in the country as the state is the largest domestic producer of hydrogen and already has a hydrogen pipeline network. In 2020, SGH2 Energy Global announced plans to use plastic and paper via plasma gasification to produce green hydrogen near Los Angeles. In 2021 then New York governor Andrew Cuomo announced a $290 million investment to construct a green hydrogen fuel production facility. Authorities in the state have also backed plans for developing fuel cells to be used in trucks and research on blending hydrogen into the gas grid. In March 2022 the governors of Arkansas, Louisiana, and Oklahoma announced the creation of a hydrogen energy hub between the states. Australia-based Woodside had already announced plans for a green hydrogen production site in Ardmore, Oklahoma.

Research and development

Albeit multiple green hydrogen technologies already exist, there is ongoing research and development for novel technological pathways for "green hydrogen". For instance, in 2020 scientists reported the development of micro-droplets for algal cells or synergistic algal-bacterial multicellular spheroid microbial reactors capable of producing oxygen as well as hydrogen via photosynthesis in daylight under air.

In 2020, the European Commission adopted a new dedicated strategy on hydrogen in the EU which includes research and innovation in line with the European Green Deal. The "European Green Hydrogen Acceleration Center" is tasked with developing a €100 billion a year green hydrogen economy by 2025.

In December 2020, the United Nations together with RMI and several companies, launched Green Hydrogen Catapult, which agitates to bring the cost of green hydrogen below US$2 per kilogram (equivalent to $50 per megawatt hour) by 2026.

In 2021, with the support of the governments of Austria, China, Germany and Italy, UN Industrial Development Organization (UNIDO) launched its Global Programme for GH2in Industry. It stimulates the accelerated uptake and deployment of GH2 in industries of developing countries and transition economies. It aims to build partnerships for knowledge and technology transfer and cooperation.

Introduction to entropy

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