Artificial sweeteners are chemical compounds that provide sweetness to food but do not add calories to the body. Aspartame is about 100-200 times sweeter, but due to decomposition when heated, its use is limited to cold foods and beverages only. Alitame is an extremely high potency sweetener whose sweetness is 2000 times that of sucrose, making its sweetness difficult to control. Since sucralose is heat stable, it is easily used in cooking and baking. Saccharin is excreted unchanged in the urine by the body without any metabolism, so it is a zero-calorie sweetener and does not provide energy.

Measurement of physical quantities is of utmost importance in checking the quality and safety of daily life. Bar, Torr, Pascal (Pa) and atmospheric pressure (atm) are the common units of pressure measurement, where 1 bar = 100,000 Pascal and 1 Torr = 1 mm of Hg. NTU (Nephelometric Turbidity Unit) is used to determine the purity and turbidity of water by measuring the scattering of light by particles suspended in water. Decibel (dB) expresses sound intensity on a logarithmic scale, while Lux is the SI unit of illuminance of visible light per unit area.

Compressed Natural Gas (CNG) consists mainly of methane (CH4) and produces minimal pollution due to complete combustion. LPG used in domestic cylinders is mainly a mixture of hydrocarbon gases butane and propane. Since natural gas is lighter than air, if CNG leaks, it will quickly rise into the atmosphere and diffuse, making it safer than LPG. LPG is heavier than air and spills onto the floor if it leaks. Both gases are odorless, so the pungent odorous ethyl mercaptan (C2H5SH) is added to LPG as a safety measure to quickly detect leaks.

A stethoscope is a diagnostic medical instrument used to listen to the soft sounds of internal organs of the human body, especially the heartbeat and airflow in the lungs. When the sound hits the chest-piece of the stethoscope, it undergoes multiple reflection from the inner surface of the narrow rubber or metal tube and reaches the doctor's ear-piece without losing energy. Sound waves are longitudinal mechanical waves, hence their polarization is not possible. Like light, sound waves also follow the laws of reflection, which is also used practically in loudspeakers, horns and sound boards.

Rayon is a semi-synthetic cellulosic fiber made by chemical reproduction of natural cellulose (wood pulp), so it is not non-cellulosic. Nylon-6,6 was the first fully synthesized fiber, which is a member of the polyamide class containing amide bonds and is extremely strong and flexible. Kevlar is a special aromatic polyamide (aramid) fiber that is widely used in bulletproof jackets, helmets and aerospace protective equipment due to its high tensile strength and lightness. Terylene is a major polyester fiber with ester linkage that does not wrinkle.

When sour or acidic food items are kept in brass (copper + zinc) utensils, copper can react with acids to form toxic copper salts, to protect against this, a thin layer of tin metal is applied inside the utensils. To protect iron from air and moisture, it is coated with molten zinc (galvanization), where zinc acts as a sacrificial anode by corroding itself and protecting the iron. Stainless steel is an alloy consisting of iron mixed with chromium (minimum 10.5%), nickel and carbon; The invisible oxide layer of chromium makes it rustproof. Silver reacts with H2S present in the air and forms a black layer of Ag2S.

Various optical effects of daily life are based on the fundamental wave and ray principles of light. Colorful patterns are formed due to interference of light waves reflected from the top and bottom surfaces of the thin membrane of a soap bubble. The bent appearance of a pencil in water is the result of light bending (refraction) towards the normal while entering from a rarer medium (air) to a denser medium (water). Optical fiber works on the principle of total internal reflection, where the refractive index of the core is greater than that of the cladding and the angle of incidence is kept larger than the critical angle. The blue color of the sky is due to excessive scattering of short wavelength blue light by atmospheric microscopic particles (Scattering proportional to 1/λ^4).

Soaps are sodium/potassium salts of fatty acids (stearic, palmitic or oleic acid). Ca2+ and Mg2+ ions in hard water react with soap to form insoluble sticky precipitate (scum), due to which the soap becomes useless. Synthetic detergents are sulfonate or sulphate salts with long alkyl chains, which form soluble compounds with hard water ions and readily foam. In micelle formation, the hydrocarbon tail of the soap molecule, being hydrophobic, gets attracted towards the oily scum and remains in the center, while the ionic end, being hydrophobic, remains located outside in the direction of water.

Sodium benzoate (C6H5COONa) is a major food preservative that prevents spoilage of jams, sauces and soft drinks by inhibiting the growth of bacteria and yeast in acidic medium. Sodium bicarbonate (NaHCO3) releases CO2 gas when heated, which makes the cake spongy, and being a weak base, it is also an antacid that reduces the acidity of the stomach. Bleaching powder (CaOCl2) is used to destroy bacteria present in water by releasing chlorine and for bleaching in textile industry. By heating gypsum at 373 K, plaster of Paris (CaSO4·1/2H2O) is obtained, which hardens again after adding water and is used in bone plaster.

In myopia, due to lengthening of the eyeball or increased curvature of the cornea, the rays focus before the retina, which is corrected by a diverging (concave) lens. In hypermetropia, light rays are focused on the retina by using a converging (convex) lens. In presbyopia, due to reduced accommodation capacity, a bifocal lens with the upper part concave (for distance vision) and the lower part convex (for near vision) is used. Cataract is an opacity of the lens caused by denaturation and agglomeration of proteins in the crystalline lens of the eye; It cannot be corrected with glasses, but the only treatment is to surgically remove the opaque lens and implant an artificial intraocular lens (IOL).

The carbonic acid-bicarbonate buffer system in the blood maintains the pH around 7.4; Even minor deviations in this can be fatal. Oxides of atmospheric sulfur and nitrogen combine with water to form sulfuric and nitric acids, due to which the pH of rain water falls below 5.6 and forms acid rain. Tooth decay begins when bacteria in the mouth break down sugar and drop the pH below 5.5, causing the hardest substance in the body, enamel, to dissolve. Bee and ant stings contain methanoic acid (formic acid), the irritating effect of which is neutralized by weak bases such as baking soda or calamine.

Evaporation is a cooling process in which the molecules on the surface of a liquid take heat from the surroundings and form vapor, due to which the water in the earthen pot remains cool. The anomalous expansion of water at 4°C ensures that in extreme cold, even when the lakes freeze over, the 4°C water at the bottom remains liquid, allowing fish to survive. Ice at 0°C has the capacity to absorb 80 calories more latent heat of fusion per gram, so ice at 0°C provides more effective cooling than water at the same temperature. Steam at 100°C has an additional latent heat of vaporization of 540 calories/gram, making it a more severe skin burn than boiling water.

Modern household appliances work on the laws of electromagnetism. A microwave oven uses microwave waves of 2.45 GHz which rapidly rotate the dipolar water molecules present in the food to produce internal heat through molecular friction. An induction stove heats the vessel directly by passing high frequency alternating current through the coil, creating eddy currents (eddy currents) and magnetic hysteresis in the metal bottom of the vessel. The transformer increases (step-up) or decreases (step-down) the AC voltage by working on Faraday's principle of mutual induction. The fuse wire is made of tin and lead alloy (63% Pb + 37% Sn) which has a low melting point so that it can melt and break the circuit on overload.

Alloys are homogeneous mixtures of two or more metals that provide superior strength and corrosion resistance. Brass contains about 70% copper and 30% zinc and is used in making utensils, sculptures and musical instruments. Bronze contains about 88% copper and 12% tin and is used in coins and medals. 'German silver' (nickel silver) is an alloy of copper (50%), zinc (30%) and nickel (20%); The amount of silver in it is zero (0%), so named because of its silvery luster. Solder is an alloy of lead and tin which has a very low melting point.

The pasteurization method invented by Louis Pasteur destroys pathogenic bacteria (such as mycobacterium) without destroying the nutrients in milk. Salt and sugar draw water from the cells of microorganisms by external osmosis and neutralize them, due to which pickles and jams remain safe for a long time. Potato chip packets are filled with inert nitrogen gas after removing air to prevent rancidity of fats and oils. Food irradiation involves killing insects and bacteria by controlled gamma rays emitted from cobalt-60; It does not introduce any residual radioactivity into the food and is completely certified safe by WHO and FSSAI.

In primary cells the chemical reaction occurs only once and after use they become inactive (like Leclanche cell where NH4Cl/ZnCl2 paste is used). Secondary cells are rechargeable where the reaction can be reversed by passing electricity (e.g. lead-acid batteries of vehicles). Lithium-ion batteries are the basis of modern electronics, the development of which was awarded the 2019 Nobel Prize. Hydrogen fuel cell converts the combustion energy of hydrogen and oxygen into electrical energy with high efficiency up to 70%; Its only emission is clean water (H2O), making it an excellent source of zero-emission green energy.

Dry ice (solid CO2) sublimates directly into a gas at atmospheric pressure without becoming a liquid, so it is used in ice cream and refrigeration of biological samples. Sodium thiosulfate (Hypo) removes unexposed silver halide from photographic film by forming soluble complexes. Alum is a double salt which, by giving Al3+ ions to water, coagulates the colloidal particles of suspended soil and settles them in sediment and is used in blood clotting. Methane, obtained from the distillation of wood, is extremely toxic and consumption can cause blindness or death.

Surface tension is the property of a liquid due to which its free surface tries to occupy minimum area like a stretched membrane; The surface area of ​​the sphere is minimum for a given volume, hence the drops are spherical. As temperature increases, surface tension decreases due to reduced intermolecular attractions, allowing hot soup to spread better on the taste buds of the tongue. On adding detergent, the surface tension of water decreases (not increases), due to which water is able to dissolve the dirt by creating deep wetting in the microscopic fibers of the clothes. Capillary action is the phenomenon of spontaneous rise of liquid in very thin tubes due to the difference in cohesive and adhesive forces.

Enzymes are special biocatalysts made of proteins that speed up the body's metabolic processes millions of times. Digestion begins in the mouth where salivary amylase partially digests carbohydrates. The gastric juice of the stomach secretes hydrochloric acid (pH 1.5-2.0) which converts inactive pepsinogen into active pepsin. Renin enzyme is important in the digestion of milk. In industrial biotechnology, environment-friendly organic detergents are combined with the addition of proteases (for blood, egg stains), amylase (for starch stains) and lipases (for oil stains) to enable excellent washing of clothes even at low temperatures.

Controlled irradiation of radioactive isotopes has widespread use in daily life and medicine. The chronology of ancient biological remains is determined based on the half-life of C-14 of 5,730 years. The thyroid gland naturally absorbs iodine, so I-131 is used as a 'targeted radioisotope' to treat thyroid overactivity and destroy cancer cells. Co-60's high-energy gamma rays reduce the size of tumors by breaking the DNA of cancer cells. Am-241, present in small amounts in smoke detectors, ionizes the air and maintains an electrical current; When smoke enters, ionization is interrupted and the alarm sounds.

The chronology of computer development is based on their main processing components. The first generation (1940–1956) had vacuum tubes, huge power consumption, and huge computers like ENIAC/UNIVAC. The second generation (1956–1964) introduced transistors for increased reliability and the use of assembly language and magnetic core memory. The third generation (1964–1971) used integrated circuits (ICs), invented by Jack Kilby and Robert Noyce, rather than microprocessors. The fourth generation (1971 onward) saw the first microprocessors such as the Intel 4004 and VLSI/LSI technologies incorporate millions of transistors on a chip, leading to the widespread use of personal computers (PC), mouse, and Windows/Mac-like GUIs.

The computer memory hierarchy is divided based on speed, price, and capacity. SRAM is made up of flip-flop circuits that hold data rapidly without refreshing and is primarily used as L1/L2/L3 cache memory. DRAM consists of transistor-capacitor pairs that lose charge slowly, so must be refreshed hundreds of times per second; This constitutes the main system RAM. EEPROM (Electrically Erasable Programmable ROM) is the basis of flash memory and modern BIOS/UEFI chips on motherboards that can be rewritten with electrical waves. Registers are integral parts of CPU architecture that directly store operands at instantaneous speed during calculations.

Data in computers is measured in binary (0 or 1) bits. A group of 4 bits is called a nibble and 8 bits together make 1 byte. Each next main unit is 1024 (2^10) times the previous unit: 1024 B = 1 KB, 1024 KB = 1 MB, 1024 MB = 1 GB, 1024 GB = 1 TB, 1024 TB = 1 PB (petabyte), 1024 PB = 1 EB (exabyte), 1024 EB = 1 ZB (zettabyte), 1024 ZB = 1 YB (yotabyte), 1024 YB = 1 brontobyte and 1024 brontobyte = 1 geopbyte. So a geobyte is the largest known storage unit of memory, not the smallest.

The operating system acts as a bridge between the hardware and the user. RTOS (such as VxWorks) operate under extremely tight time constraints, which are required for space missions and defense systems. For national security and self-reliance in India, C-DAC developed BOSS Linux, the latest version of which is 'Pragya'. To enhance the security and privacy of Indian mobile users, IIT Madras-backed JandKops created 'BharOS', which is based on open-source and gives complete freedom to users to choose the apps of their choice. Google's Android operating system is an open-source OS based on the 'Android Open Source Project' (AOSP), and not completely closed-source.

Network topology refers to the physical and logical configuration of nodes. Star topology is most commonly used in modern LANs because data management is easier through a central switch and the entire network remains safe if one computer's cable fails. Bus topology is the simplest and has the fewest cables, but failure of the backbone cable brings the entire network to a standstill. Mesh topology requires N(N-1)/2 links for N nodes, making it extremely expensive but impenetrable for military and critical networks. In ring topology, data moves in the same direction and collisions are less.

In the evolution of mobile telephony, 1G (1980s) was purely analog, lacking security and data features. 2G (1990s) introduced digital encryption, better voice quality and text messaging (SMS). 3G paved the way for mobile broadband and video calling. 4G LTE is a completely all-IP packet-switched network, using VoLTE (Voice over LTE) instead of circuit-switched voice, so 4G is not circuit-switched. 5G New Radio (NR) technology offers high bandwidth, ultra-low latency (1 ms) and 'network slicing' that divides a single physical network into multiple virtual networks.

The division of 5G spectrum is three-tier based on frequency. Waves in low-bands such as 700 MHz travel far and easily penetrate walls of buildings, which is suitable for rural and wide coverage. The mid-band (C-Band) of 3.3-3.6 GHz is the cornerstone of commercial 5G services as it balances both sufficient speeds and satisfactory area coverage. Millimeter wave (mmWave) bands like 26 GHz provide gigabit speeds in stadiums, malls and dense urban centers but are blocked by trees and walls. The 'India 6G Vision' document released by the Government of India in March 2023 targets terahertz (THz) communications through the Bharat 6G Alliance (B6GA) and a 10% share in global 6G intellectual property by 2030.

Wireless technologies use different parts of the electromagnetic spectrum. Bluetooth (IEEE 802.15.1) connects small devices (headphones, smartwatches) in low energy using 2.4 GHz radio frequency. Wi-Fi (IEEE 802.11 series) provides high-speed Internet over 2.4 GHz, 5 GHz, and the recent Wi-Fi 6E/7 at 6 GHz radio waves. NFC works via electromagnetic induction at 13.56 MHz and is used in Metro cards, Fastag and contactless credit card swipes. Li-Fi (Light Fidelity) enables secure data transmission at gigabit speeds using rapid on-off pulses of visible light (Visible Light Communication - VLC) from LED bulbs rather than radio waves.

IoT is an integrated system where physical devices connect to the Internet and share data. The perception layer is the 'eyes and ears' of the system that transforms physical world variables into digital signals. The network layer transports data over various protocols (e.g. MQTT, CoAP, Cellular) to the gateway and cloud. Due to the huge volume of data of IoT, it is centrally analyzed by advanced algorithms on cloud servers or edge servers located at the edge of the network, and not just on simple smartphones. ITMS cameras and automated sensors installed in smart cities reduce congestion by automatically adapting traffic signals.

Artificial Intelligence (AI) is a broad science under which Machine Learning (ML) and Deep Learning (DL) hierarchically fall. In supervised learning (e.g. spam email detection) the model learns relationships from a labeled dataset. In unsupervised learning (such as customer classification or anomaly detection) the raw data is given without any answer-key and the algorithm itself creates groups with similar characteristics. Reinforcement learning (such as autonomous driving cars or AlphaGo games) works on the policy of obtaining maximum cumulative rewards in a dynamic environment where correct decisions receive positive points and mistakes receive penalties.

The foundation of Generative AI rests on the 'Attention-Based Transformer Model' developed in 2017, from which LLMs like ChatGPT, Gemini and Claude have evolved. The Government of India has launched 'Bhasini' platform to eliminate linguistic barriers, which provides text-to-speech, speech-to-text and multilingual translation. The 7 key pillars of 'IndiaAI Mission', approved by the Union Cabinet in March 2024 with an outlay of ₹10,372 crore, include AI compute capacity, AI dataset and AI future skills. Hallucination is a major technical limitation of LLM where the sentence structure is grammatically correct based on statistical probability but the facts presented in it are completely misleading or fabricated.

Each block in the blockchain contains data, its own cryptographic hash and the hash of the previous block, the connected chain of which is protected by a consensus mechanism. Smart contracts are automated code that makes insurance claims, real estate and supply chains transparent by removing middlemen. Cryptocurrencies like Bitcoin are completely decentralized and free from any central authority, making their value highly volatile. In contrast, CBDC (Digital Rupee) is a sovereign digital currency backed by the country's Central Bank (RBI) which has a stable 1:1 exchange rate similar to physical currency and is official legal tender.

Modern forms of cyber attacks include ransomware (such as WannaCry) that takes computer networks hostage, while phishing uses social engineering to steal bank details. The DPDP Act 2023 passed by Parliament is India's first comprehensive data privacy law, which provides for consent requirement, purpose limitation, data minimization and right to erasure of citizens; Under this, Data Protection Board (DPBI) has been constituted. CERT-In (Indian Computer Emergency Response Team), functioning under MeitY, protects the country's cyber space and mandates entities to report incidents within 6 hours for rapid analysis of cyber attacks.

Digital India and Rajasthan e-Governance framework have simplified citizen services. DigiLocker provides legal recognition equivalent to physical originals to digital documents issued under Rule 9A of the IT Act 2000. UMANG (Unified Mobile Application for New-age Governance) app is a single mobile gateway to thousands of government services like EPF, Income Tax, Gas Booking. Rajasthan Government's Jan Aadhaar Scheme (2019) has become a transparent basis for DBT by providing 10-digit family ID to every family and 11-digit personal identity to each member. Rajasthan Sampark Portal (Dial 181) ensures multi-level monitoring of timely disposal of complaints of all departments.

Rajasthan is among the leading states in the country in adopting e-governance and modern technology. The 'Rajasthan AI-ML Policy 2026' approved by the state cabinet emphasizes on the use of Artificial Intelligence in governance, creation of data center hubs and skill development of youth. RajSSO is a centralized authentication system that eliminates the problem of remembering different passwords again and again. The e-Mitra model is the most successful Public-Private Partnership (PPP) based citizen service mechanism in the country. To combat cyber frauds with increasing digital transactions, Rajasthan government has approved setting up of state-of-the-art 'R4C' and AI-enabled 1930 cyber helpline at a cost of ₹100 crore.

An Internet Protocol (IP) address is a unique numerical label given to each device connected to a network. IPv4 (Internet Protocol version 4) is a 32-bit address, written in decimal form in 4 parts (e.g. 192.168.1.1); Its total theoretical capacity is approximately 4.3 billion addresses which has been exhausted due to the growth of Internet devices around the world. IPv6 developed to overcome this limitation uses a 128-bit hexadecimal format (e.g. 2001:0db8:85a3::8a2e:0370), which provides 3.4×10^38 (almost unlimited) addresses and is capable of giving individual IP addresses to every object in the modern IoT era.

The classification of virtual technologies depends on their immersion level. VR (such as Meta Quest) creates an artificial world that completely surrounds the user's vision, which is used in flight simulation and surgical training. AR (like Google Lens or Ikea Furniture App) allows you to place a virtual sofa in a real room and view it through a smartphone camera. MR (e.g. Microsoft HoloLens) is an advanced combination of these two where a virtual object can bounce off a real table. The Metaverse is a permanent, shared and immersive network of interconnected 3D virtual worlds where people act, communicate and conduct economic transactions through their digital avatars.

Deepfakes are created by GANs (Generative Adversarial Networks) where two neural networks (generator and discriminator) compete with each other to produce highly accurate and incredibly realistic fake video/audio. To prevent its increasing misuse, the Ministry of Electronics and Information Technology (MeitY) made stringent amendments in the IT (Intermediary Guidelines) Rules in February 2026. Under these rules, all intermediary platforms will have to provide clear warning labels on AI content, it is made legally mandatory to remove general misleading content within 3 hours and non-consensual obscene or intimate AI content (NCII) within just 2 hours of complaint.

Cloud computing is a model of supplying computing resources on-demand. IaaS has hardware level control where the OS and apps are managed by the user himself. In PaaS, the hardware and OS are managed by the cloud provider and the user only executes the code. In SaaS, the user does not require any installation and uses the service directly from the browser. For security and cost optimization, organizations adopt hybrid cloud, where sensitive financial data is operated on internal private cloud and common functions are operated on public cloud (AWS/Azure).

Big Data deals with extremely large and complex datasets. Its main hallmarks are 5Vs – Large Volume, Fast Production Rate, Unstructured/Structured Format (Variety), Veracity of data and business/social benefit derived from it (Value). Data analytics works at 4 levels: descriptive (what happened), diagnostic (why it happened), predictive (what could happen) and prescriptive (what action should we take for the best outcome). Therefore, prescriptive analytics suggests specific business decisions and action plans through simulation and optimization algorithms.

ISRO's structure is divided into specialized research and operational centres. VSSC located in Thiruvananthapuram is the main center for design of launch vehicles (PSLV, GSLV, LVM3) and rocket technology. URSC (formerly ISAC), Bengaluru, is a premier institute for manufacturing communication, navigation and remote sensing satellites. SDSC-SHAR at Sriharikota (Andhra Pradesh) is India's primary spaceport from where satellites are launched. Hyderabad based NRSC's Regional Centre-West (RRSC-W) established at Jodhpur (Rajasthan) undertakes natural resource mapping and desertification monitoring, particularly in the Thar Desert, Western India.

PSLV is India's 'workhorse' rocket whose first and third stages are filled with solid propellant (HTPB) and second and fourth stages are filled with liquid propellant (UDMH + N2O4). Its second stage is powered by the famous 'Vikas' engine developed by the Liquid Propulsion Systems Centre. GSLV Mk-II consists of three stages (solid + liquid + cryogenic). In cryogenic technology, liquid hydrogen (LH2, temperature -253°C) is used as fuel and liquid oxygen (LOX, temperature -183°C) as oxidizer; Therefore, writing the role of gases in reverse is technically incorrect.

LVM3 (Baahubali rocket) is capable of sending satellites weighing up to 4,000 kg to GTO and up to 8,000 kg to LEO; It has successfully launched Chandrayaan-2, Chandrayaan-3 and heavy communication satellites. Its C25 stage is powered by a CE-20 engine manufactured by the Liquid Propulsion Systems Centre. SSLV (Small Satellite Launch Vehicle) is a mini-rocket designed to launch nano/micro satellites up to 500 kg in just 15 days with a turnaround time of 72 hours. The new launch center being built at Kulasekharapattinam in Tamil Nadu will allow rockets to be fired directly towards the south, which will avoid the need for satellites to take a dogleg maneuver over Sri Lanka and save fuel.

NavIC (Navigation with Indian Constellation) is India's independent regional navigation system that ends strategic dependence on US GPS. In its constellation, 3 satellites are installed in geostationary orbit (GEO) and the remaining in inclined geosynchronous orbit (GSO, 29° inclination). It provides Standard Positioning Service (SPS) for civilians and Encrypted Restricted Service (RS) for authorized defense users on L5 and S-band frequencies. GAGAN (GPS Aided GEO Augmented Navigation) system ensures accurate landing and navigation of aircraft in Indian airspace by correcting errors in GPS signals for civil aviation safety.

Cartosat-3 is a state-of-the-art Earth Observation satellite with sub-meter resolution (0.28 m) capable of high precision mapping. The RISAT series uses X-band and C-band synthetic aperture radar, which is extremely useful in border surveillance and disaster management due to its ability to capture images day and night and through dense clouds. GSAT-7A (aka 'Angry Bird') is a dedicated satellite of the Indian Air Force that creates a seamless communication network between air combat aircraft, AWACS and drones (whereas GSAT-7 'Rukmini' is a Navy satellite). INSAT-3DS is an advanced weather satellite launched by GSLV-F14 in February 2024 to continuously analyze sea surface and atmospheric dynamics.

Chandrayaan-3 mission created history by launching with LVM3-M4 rocket. August 23 was declared 'National Space Day' every year to commemorate the landing success. The lander's payloads included ChaSTE (thermal conductivity), ILSA (seismometer for lunar seismicity measurements) and RAMBHA-LP (plasma density). The LIBS and APXS payloads of the Pragyan rover provided undisputed confirmation of aluminium, calcium, iron, titanium as well as sulfur in healthy lunar soil. Earlier, only the Soviet Union, America and China had been able to make a soft-landing on the Moon, but India became the first nation in the world to reach the extremely inaccessible South Pole.

Aditya-L1, launched by PSLV-C57 on 2 September 2023, is India's first Sun-dedicated space observatory mission. At the L1 point the satellite has a continuous view of the Sun and consumes minimal fuel. The spacecraft has a total of 7 scientific payloads: 4 remote sensing payloads – VELC (Corona), SUIT (Ultraviolet Imaging), SoLEXS and HEL1OS (Soft and Hard X-ray Spectrometers); And 3 in-situ payloads – ASPEX and PAPA (Solar Wind and Plasma Analyser) and Advanced Magnetometer. Therefore, it conducts a multi-dimensional comprehensive study of X-rays, ultraviolet, visible light and solar particles.

The Gaganyaan mission is the biggest leap forward in India's self-reliant space exploration capability, for which the LVM3 rocket has been certified human-rated (HLVM3). The Crew Escape System (CES) and Test Vehicle (TV-D1) tests have been successful in evacuating astronauts in case of emergency. The Vyommitra robot will monitor the life support systems inside the capsule and simulate human switch operations. The successful SpaDeX mission in January 2025 achieved autonomous docking capability, which is essential for the integration of BAS modules and the Chandrayaan-4 sample-return mission. India also has a long-term goal of landing Indian astronauts on the Moon by 2040.

NISAR is the most advanced and expensive joint scientific Earth observation mission ever undertaken between India (ISRO) and the United States of America (NASA). The advanced Sweep-SAR technology used in it provides a wide 240 km swath with high resolution. L-band penetrates dense forest canopy and measures soil moisture and surface movement, while S-band is capable of studying vegetation and coastal processes. The satellite will be placed in a polar sun-synchronous orbit (SSPO/LEO) at an altitude of 747 km to provide regular and consistent reconnaissance data of the entire Earth's surface every 12 days; It will not be placed in the 36,000 km GEO.

The 'Kármán Line', named after the Hungarian-American physicist Theodore von Kármán, is an imaginary boundary located at an altitude of 100 km (about 62 miles) above sea level. At this altitude the Earth's atmosphere becomes so extremely thin that no conventional aircraft can achieve aerodynamic lift on its wings; To keep flying it has to attain orbital velocity. The World Air Sports Federation (FAI) and most international scientific organizations officially consider an altitude of 100 km as the beginning of space. Any mission that crosses this line is considered a true space flight.

The IGMDP, initiated by the Defense Research and Development Laboratory (DRDL), Hyderabad in 1983, made India self-reliant in strategic missile technology (the program was declared successful in 2008). The five systems developed under it were: Prithvi (short-range surface-to-surface ballistic), Agni (medium/long range tactical missile), Trishul (quick reaction surface-to-air), Akash (medium range surface-to-air), and Nag. 'Naag' is a third generation 'Fire-and-Forget' anti-tank guided missile (ATGM) which is equipped with an Imaging Infrared (IIR) seeker and automatically engages the target after firing, hence it is not controlled by wire.

The Agni series is the basis of India's strategic nuclear deterrence. Agni-I (700-1200 km), Agni-II (2000-2500 km), Agni-III (3000-3500 km) and Agni-IV (4000 km) are included in India's Strategic Forces Command (SFC). Agni-V has a range of 5000-5500+ km. In March 2024, through 'Mission Divyastra', India proved MIRV technology, which allows a single missile to independently drop nuclear warheads on multiple targets (making India the sixth country in the world to have this capability). Agni-Prime is a next generation missile with a range of 1000-2000 km, whose canistered form allows it to be kept stealthy for a long time and can be fired immediately from rail/road.

BrahMos is a joint venture between India (DRDO) and Russia (NPO); It is the world's fastest operational anti-ship/land-attack supersonic cruise missile with two stages (solid booster + liquid ramjet). Nirbhay Manik is a subsonic cruise missile powered by turbofan engine that can fly at tree height while avoiding radar. Shaurya missile is the ground version of Sagarika (K-15) which has a strike range of 700-1000 km at a hypersonic speed of Mach 7.5. Pralay is a solid-propellant semi-ballistic surface-to-surface missile capable of maneuvering its flight path to dodge enemy air defense interceptor radars in conventional battlefields.

India is the fourth country after the US, Russia and Israel to develop indigenous 2-layer ballistic missile shield. PAD/Pradyumna and PDV shoot down the missile coming outside the atmosphere (exo-atmospheric) in space itself, while AAD/Ashwin destroys the target in the terminal stage inside the atmosphere (endo-atmospheric). Additionally, the S-400 Triumph provides long-range shielding to the Air Force's air defense grid. Indian Army's 'Project Akashteer' ensures 360-degree integrated air defense control against low altitude threats, drones and cruise missiles by connecting all radars, sensors, sky, surface and artillery in a digital network.

Tejas is modernizing the MiG-21 fleet in indigenous aeronautics; The Tejas Mk-1A is equipped with advanced AESA radar, beyond-visual-range missiles (Astra) and mid-air refueling capability. The AMCA program (Aeronautical Development Agency + HAL) is developing a 5th generation stealth fighter with internal weapon bay, radar-absorbent material (RAM) and supercruise capability for the Indian Air Force. In the UAV sector, DRDO's Rustom-2/TAPAS is capable of performing real-time surveillance and intelligence gathering (ISR) by flying continuously for 18+ hours at an altitude of 28,000 feet.

In armored warfare, the Arjun MBT (developed by DRDO) is equipped with heavy firepower and indigenous 'Kanchan' armor that neutralizes anti-tank shells. 'Zoravar' (DRDO + L&T) is a 25-tonne light tank designed with rapid air-lift capability to counter Chinese light tanks (Type 15) in difficult mountainous battlefields like eastern Ladakh after Galwan Valley. The Pinaka MBRL system fires rockets at enemy targets with precision (recently its guided missile range has been increased to 120 km). The K9 Vajra is capable of delivering heavy fire while moving with armored brigades in desert and mountainous areas with high mobility.

The Indian Navy operates two active aircraft carriers in the Indian Ocean as a 'Blue Water Navy': INS Vikramaditya and indigenous INS Vikrant (76% indigenous content, fitted with STOBAR system, where MiG-29K and naval helicopters are deployed). Under Project-75, six Scorpene submarines – Kalvari, Khanderi, Karanj, Vela, Vagir and Wagshir – have been built. The most important and invisible sea pillars of India's Nuclear Triad are INS Arihant and INS Arighat, which provide an accurate second-strike capability to fire K-15 (750 km) and K-4 (3500 km) nuclear missiles while remaining underwater for months.

Laser and microwave technology are replacing traditional gunpowder on the battlefield of the future. DEW weapons disable enemy drones, rockets and optical sensors by burning them out in seconds at almost zero cost per shot (electrical energy only). 'DURGA-II' and Laser DEW Mk-II(A) developed by DRDO's CHESS laboratory are India's major projects in this direction. The iDEX scheme of the Defense Ministry (under the Defense Innovation Organisation) provides financial grants ranging from ₹1.5 to ₹10 crore to startups to bring self-reliance in the defense sector. The 'Abheda' jacket has significantly reduced weight by using advanced composite materials with high protection (BIS Level-6) for the soldiers.

Rajasthan is an extremely important center of India's strategic and space history. Pokhran of Jaisalmer is a symbol of India's nuclear sovereignty where India became a nuclear power by conducting underground nuclear blasts in 1974 and 1998; This range is still a major center for live-firing exercises (e.g. Vayushakti) of the Army and Air Force. In space science, Udaipur Solar Observatory (established 1975, by Dr. Arvind Bhatnagar) is counted among the best observatories in the world in the study of solar magnetic field and solar flares due to its calm aquatic environment. Mount Abu based 1.2 meter infrared telescope is engaged in the discovery of new exoplanets by high-resolution spectroscopy (PARAS).

'Daksh' is a battery-powered Remotely Operated Vehicle (ROV) developed by DRDO's Research and Development Establishment (Engineers), Pune. It is capable of climbing stairs, navigating narrow streets and capturing suspicious bags, IEDs and explosives with its robotic arm and scanning it with X-ray equipment controlled by radio frequency from a safe distance of 100-500 meters. It safely defuses the bomb with an on-board water-jet disruptor, thereby preventing the lives of security forces personnel from being put at risk. Mantra is an unmanned armored tracked vehicle, while Rustom and Lakshya are reconnaissance and pilot-less target drones respectively.

Gregor Johann Mendel propounded the basic rules of genetics by studying 7 pairs of recessive traits on the pea plant (Pisum sativum). According to the law of dominance, only the dominant trait appears in the F1 generation. The law of segregation is universal because only one allele of each pair enters the gametes. The law of independent inheritance explains the independent inheritance of two different traits. But when two genes are located very close together on the same chromosome, they exhibit 'linkage' discovered by Thomas Hunt Morgan and do not separate independently; Therefore, attachment is a major known exception to the law of independent discharge.

Haemophilia ('Royal disease') is caused by a recessive gene located on the X-chromosome, which causes the blood to not clot; Women are carriers and men are more affected. Sickle cell anemia is caused by a point mutation (GAG to GUG) on the 11th autosome, which replaces glutamic acid with valine at the sixth position of the beta-globin chain of hemoglobin, causing RBCs to become sickle-shaped at low oxygen levels. Deficiency of phenylalanine hydroxylase enzyme in phenylketonuria causes mental impairment. Color blindness is an X-linked recessive disorder in which the red or green cones in the retina of the eye are defective.

Aneuploidy disorders arise due to non-disjunction (chromosomes not separating during meiosis). Down syndrome (discoverer: Langdon Down, 1866) is a trisomy of the 21st autosome, characterized by short stature, round face, broad palms, and mental retardation. Turner syndrome is the only known viable monosomy (XO) in which the ovaries remain underdeveloped. Klinefelter syndrome (XXY) In males, the testicles remain underdeveloped and they develop female-like symptoms. Edwards syndrome is caused by trisomy of the 18th chromosome (Trisomy-18), while trisomy of the 13th chromosome is called 'Patau Syndrome'.

The Human Genome Project ushered in a new era of bioinformatics, revealing that more than 98% of human DNA is non-coding and only 0.1% of individual variation is due to single nucleotide polymorphisms (SNPs). Due to the extreme genetic diversity of India (over 4,500 endogamous groups), Western reference genomes were not fully applicable to Indian diseases and drug responses. Therefore, DBT carried out the 'Genome India Project' in collaboration with 20 premier institutions led by IISc Bengaluru and sequenced the complete genome of 10,000 Indian individuals and stored it in IBDC Faridabad (India's first national life-sciences data repository), which will form the basis for personalized medicine and identification of rare genetic diseases.

RNA plays a central role in the Central Dogma: DNA → RNA → Protein. mRNA carries genetic information to the ribosome in the form of triplet codons. tRNA is an adapter molecule with a clover-leaf like structure with an amino acid binding site at one end and an anticodon loop at the other. rRNA makes up 80% of the ribosome and plays a catalytic role (ribozyme) in peptide bond formation. siRNA and miRNA are small non-coding RNAs of 20–25 nucleotides that bind to target mRNA and inhibit its translation by RNA interference (RNAi); Andrew Fire and Craig Mello received the 2006 Nobel Prize for the discovery of RNAi.

CAR-T cell therapy is called a 'living drug' because it trains the patient's own immune system against cancer. It has proven to be highly effective in blood cancers such as leukemia and lymphoma. The cost of this treatment abroad ranges from ₹3 to ₹4 crore, making it out of the reach of most Indians. 'NexCAR19' developed by ImmunoAct in collaboration with IIT Bombay and Tata Memorial Hospital received commercial use approval by the Central Drugs Standard Control Organization (CDSCO) in October 2023, making it available at about 90% lower cost (approximately ₹30-35 lakh) compared to western countries.

Gottlieb Haberlandt is considered the father of plant tissue culture. The nutrient medium contains carbon source (sucrose), inorganic salts, vitamins and plant hormones (auxin and cytokinin). Auxin stimulates root growth and cytokinin stimulates stem growth. Thousands of genetically identical plants (somaclones) are produced in a short time by micropropagation. To obtain virus-free plants, the apical or axillary meristem culture of the plant is used, because the rate of cell division in the meristem region is faster than the multiplication of the virus and due to the absence of vascular tissue the virus cannot reach there; Xylem/phloem does not result in virus-free plants.

India's National Biofuels Policy 2018 (revised 2022) classifies biofuels on the basis of generations. Bioethanol is made from edible grains in 1G. 2G (Advanced Biofuel) produces cellulosic ethanol from agricultural wastes (e.g. 2G Ethanol Refinery in Panipat). In 3G the algae are grown on water bodies or barren lands and yield high oil per acre of land. 4G involves altering the genome of algae through synthetic biology to produce hydrocarbon fuel directly by absorbing CO2 from the atmosphere, making it beyond carbon neutral to a carbon-negative energy source. Under Policy 2022, the target of 20% ethanol blending (E20) in petrol has been reduced from 2030 to 2025-26.

Microorganisms are natural scavengers in environmental biotechnology. The superbug (Pseudomonas putida) was the world's first patented genetically modified microorganism that breaks down octane, xylene and hexane from oil spills. The 'Oilzapper' bacteria mixture developed by TERI is also used to clean up oil pollution in India. In phytoremediation, sunflower, mustard or willow plants pull heavy metals like lead, arsenic and uranium from the soil. In biomagnification, fat-soluble and non-biodegradable pollutants like DDT or mercury increase at each trophic level (concentration does not decrease, but multiplies) as we move from the bottom up in the food chain.

Human insulin (humulin), produced using recombinant DNA technology, eliminated the allergy problems of insulin derived from animal pancreas. Hepatitis B vaccine is the first human vaccine produced by recombinant DNA technology. Hybridoma technology (Nobel Prize 1984) produces single-type pure antibodies (monoclonal antibodies) against specific antigens, which are used in cancer therapy (e.g. trastuzumab) and diagnostics. Nafithromycin (brand name 'Miknaf') is India's first indigenously developed next generation antibiotic developed with the support of BIRAC for the treatment of drug-resistant respiratory infections.

The historical development of nanotechnology has been multi-stage. Feynman (who is considered the ideological father of nanotechnology) predicted the ability to manipulate atoms one by one. Taniguchi coined the term 'nanotechnology' in 1974 for manufacturing techniques with tolerances of less than 1 nanometer. STM, developed by Binnig and Rohrer at IBM Zurich, works on the quantum tunneling effect and can not only see but also move atoms (for which it received the Nobel in 1986). Drexler theorized molecular manufacturing and warned that if self-replicating nanorobots went unchecked, they could consume all of Earth's biomass and cause a global disaster called 'grey goo'.

The properties of materials at the nanoscale are governed by quantum mechanics rather than classical physics. The high surface area makes nanoparticles extremely powerful catalysts. Surface Plasmon Resonance causes gold nanoparticles to absorb/scatter specific wavelengths of light, causing 20 nm gold to appear ruby-red. Due to the high surface energy and loosely bound surface atoms, the melting point of nanoparticles is much lower than that of the bulk material (e.g. the melting point of 3 nm gold drops from 1064°C to about 300°C). The bandgap energy level of semiconductors increases (changes) as nanosize decreases due to quantum confinement, causing them to emit light of different wavelengths.

Dendrimers are three-dimensional, highly branched nanoscale macromolecules whose hollow internal cavities can contain drug molecules. Liposomes are artificial vesicles with a bilayer of phospholipids that deliver chemotherapy drugs (such as doxorubicin) directly to tumors, reducing their toxicity. Nano-TiO2 and ZnO used in sunscreens remain transparent without scattering visible light but completely absorb harmful UV-A and UV-B radiation. Quantum dots (2-10 nm semiconductor crystals) change shape to emit pure red, green or blue light, increasing energy efficiency and color purity in display technology.

The decomposition behavior of nanomaterials is of utmost importance in nanotoxicology. PLA and PLGA have been approved by the US FDA as safe and biocompatible for drug delivery and dissolvable sutures in the human body because their degradation products are safely eliminated in the natural metabolic cycle (Krebs cycle). Chitosan (derived from shrimp/crab shells) and alginate (from sea grass) are non-toxic natural nano-carriers. Metal and silica nanoparticles do not biodegrade in the body or the environment. Carbon nanotubes (CNTs) are extremely inert and non-biodegradable due to their strong graphitic structure; Their accumulation in the lungs can cause asbestos-like inflammation and fibrosis.

The Government of India, following the Nano Science and Technology Initiative (NSTI) in 2001, launched the 'Nano Mission' with a budget of ₹1,000 crore in 2007 (Phase-II extended beyond 2012). Pro. CNR Under Rao's guidance, the Mission established 19 Centers of Excellence in 14 institutions across the country. INST Mohali is a major center for nano-research in agriculture, health and energy. India ranks 3rd globally, after China and the US, and not 50th in the number of high-impact publications and patents in the field of nanotechnology.

According to the classification proposed by Mihail Roco of the US National Science Foundation (NSF), nanotechnology has evolved into 4 generations: First generation (about 2000) – passive nanostructures (stabilizing properties, coatings, aerosols, composites); Second generation (circa 2005) – active nanostructures (targeted drug particles responding to external stimuli, nano-sensors, transistors); Third generation (circa 2010) – integrated nanosystems (3D nano-networking, lab-on-a-chip, nanorobotics); And fourth generation (2015 onwards) – molecular nanosystems (construction of molecular machines and artificial organs by atom-by-atom self-assembly).

High-level materials and nano-research is increasing rapidly in Rajasthan. The MRC Center at MNIT Jaipur provides advanced femtosecond laser and electron microscopy facilities for characterization of nanomaterials, polymers and solar cell materials. Carbon nanotube based nano-membranes physically filter out heavy metals and extremely small microorganisms (including viruses) dissolved in water due to their ultra-fine pores (1-2 nm). In agricultural biotechnology, 'Abu Saunf-440' developed for the foothills of Mount Abu was registered under PPV&FRA in July 2025. Institutes of national importance like BITS Pilani, IIT Jodhpur and MNIT Jaipur in the state are active in advanced nano-research.

Protection of biological wealth is a strategic issue for biodiversity rich countries like India. The patents taken by multinational companies on wound healing properties of turmeric (University of Mississippi) and Basmati rice (RiceTech Company) were canceled by India by providing scientific evidence through CSIR. Terminator gene (Genetic Use Restriction Technology - GURT) is a controversial technology used by seed companies to protect their intellectual property and is legally banned in India. TKDL, created by CSIR and Ministry of AYUSH, has a database of more than 4 lakh formulations of ancient texts of Sanskrit, Urdu and Persian in international languages ​​which is India's strongest shield against biopiracy.

The National Biopharma Mission (₹1,500 crore), run by BIRAC under the aegis of the Department of Biotechnology (DBT), has set up shared testing laboratories, clinical trial networks and bio-incubators in the country. The 'BioE3 Policy' approved by the Union Cabinet envisages eco-friendly bio-based economy, precision medicine, bio-foundries and indigenous manufacturing of carbon capture products. India's bio-economy has grown from $10 billion in 2014 to cross $165.7 billion by 2024 and has an ambitious target of $300 billion by 2030, with major contributions from vaccine production, bio-agri and bio-services.

'Agrobacterium tumefaciens' is a soil bacterium that naturally causes crown gall (tumor) disease in dicotyledonous plants. It has a huge 'Ti-plasmid' (Tumor Inducing Plasmid), whose T-DNA fragment is inserted into the genome of the plant by the bacterium. Genetic scientists have removed the harmful tumor-causing genes from this plasmid (creating a disarmed vector) and added useful genes (such as insect-resistance or drought-tolerant genes) to it. When this transformed plasmid enters the plant cell, it permanently integrates the desired gene into the plant's chromosome, hence it is called 'nature's genetic engineer'.

Carbohydrates are the body's primary energy source, while proteins are the 'building blocks' for tissue growth, repair of wear and tear and enzyme production; Both give about 4 kcal of energy per gram. Fat is the most dense energy source (9 kcal/g). Protein accounts for about 16-18% of the total adult human body weight, not 60%. Of the 20 standard amino acids found in the human body, 9 are essential (e.g. lysine, methionine, tryptophan, leucine), which the body cannot produce on its own and must be obtained through a balanced diet (pulses, milk, eggs).

Kwashiorkor (a Ghanaian word meaning 'disease of the displaced child') is caused by a specific protein deficiency in which a decrease in the albumin protein in the blood causes fluid to leak into the tissues, causing swelling in the abdomen and legs (oedema) and fat accumulation in the liver. Marasmus is caused by giving low calorie and low protein thin diet in place of mother's milk in infants below one year of age, in which the body becomes completely dry and becomes like a skeleton and there is no swelling. In xerophthalmia, keratinization of the corneal epithelium occurs which can lead to permanent blindness. Pellagra is caused by niacin (vitamin B3) deficiency.