Creation of something from nothing is against the law of

1. Understanding Matter and Mass (basic)

To understand the physical world, we must start with the most fundamental building block: Matter. In its simplest sense, matter is anything that occupies space and has mass. Whether it is the air you breathe, the water you drink, or the device you are holding, everything is composed of tiny particles called atoms and molecules. For instance, while a gold ring is made of gold atoms, a water molecule (H₂O) consists of two hydrogen atoms and one oxygen atom bonded together Science, Class VIII NCERT, Particulate Nature of Matter, p.115.

While we often use the terms 'mass' and 'weight' interchangeably in daily conversation, they represent very different physical concepts in mechanics. Mass is the measure of the actual quantity of matter present in an object Science, Class VIII NCERT, The Amazing World of Solutes, Solvents, and Solutions, p.141. It is an intrinsic property, meaning it does not change regardless of where the object is located in the universe. In contrast, weight is the force with which gravity pulls on that mass.

Feature	Mass	Weight
Definition	Quantity of matter in an object.	Gravitational force acting on an object.
Constancy	Remains constant everywhere.	Changes based on local gravity (e.g., Moon vs. Earth).
SI Unit	Kilogram (kg)	Newton (N)

A critical principle in mechanics is that matter cannot simply be created out of nothing (ex nihilo), nor can it vanish into nothingness. This is known as the Law of Conservation of Mass. In any chemical reaction or physical change, the total mass of the reactants must equal the total mass of the products Science, Class X NCERT, Chemical Reactions and Equations, p.3. In modern physics, this is further refined by Einstein’s mass-energy equivalence (E = mc²), which tells us that mass and energy are two sides of the same coin, and the total sum of mass-energy in an isolated system remains constant.

Sources: Science, Class VIII NCERT, Particulate Nature of Matter, p.115; Science, Class VIII NCERT, The Amazing World of Solutes, Solvents, and Solutions, p.141; Science, Class VIII NCERT, Exploring Forces, p.75; Science, Class X NCERT, Chemical Reactions and Equations, p.3

2. Energy: Forms and Transformations (basic)

In the study of mechanics and ecology, energy is defined as the capacity to do work. It is not a physical substance but a property of matter that can be transferred or converted. Energy exists in two primary states: Kinetic Energy (the energy of motion) and Potential Energy (stored energy based on position or state). For instance, the blowing wind possesses kinetic energy that can be harnessed through turbines INDIA PEOPLE AND ECONOMY, TEXTBOOK IN GEOGRAPHY FOR CLASS XII (NCERT 2025 ed.), Mineral and Energy Resources, p.61. Similarly, thermal energy is essentially the vibrational kinetic energy of molecules, which we perceive as temperature Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY, p.8.

A fundamental pillar of science is the Law of Conservation of Energy (derived from the First Law of Thermodynamics), which states that energy can neither be created nor destroyed. It can only be transformed from one form to another. In any isolated system, the total quantity of mass-energy remains constant. This means that when we "use" energy, we are actually just converting it. For example, a battery uses internal chemical reactions to generate a potential difference, setting electrons in motion to create electrical energy. This electrical energy can then be transformed into mechanical energy to rotate a fan or into thermal energy to heat a coil Science, class X (NCERT 2025 ed.), Electricity, p.188.

Humanity relies on various energy resources, which are typically classified into two categories: conventional (like coal, petroleum, and firewood) and non-conventional (like solar, wind, and tidal energy) NCERT (2022), Contemporary India II: Textbook in Geography for Class X (Revised ed.), Print Culture and the Modern World, p.113. Regardless of the source, the principle remains the same: we capture energy in one form—such as the chemical energy stored in coal or the kinetic energy of falling water (hydel)—and convert it into a usable form like electricity to drive our machinery and light our homes.

Sources: INDIA PEOPLE AND ECONOMY, TEXTBOOK IN GEOGRAPHY FOR CLASS XII (NCERT 2025 ed.), Mineral and Energy Resources, p.61; Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY, p.8; Science, class X (NCERT 2025 ed.), Electricity, p.188; NCERT (2022), Contemporary India II: Textbook in Geography for Class X (Revised ed.), Print Culture and the Modern World, p.113

3. Laws of Chemical Combination (intermediate)

In the study of chemistry and physics, the universe operates under a strict principle of 'no free lunches.' The most fundamental of these is the Law of Conservation of Mass, which tells us that matter is neither created nor destroyed during a chemical reaction. When you burn a piece of wood, the mass doesn't simply vanish; it transforms into ash, carbon dioxide, and water vapor. If you were to weigh all these products, they would exactly equal the mass of the original wood and the oxygen consumed during combustion. This principle is the cornerstone of why we balance chemical equations—every single atom must be accounted for on both sides of the arrow Science, Class X (NCERT 2025 ed.), Chapter 1: Chemical Reactions and Equations, p. 3.

While conservation of mass governs chemical reactions, the First Law of Thermodynamics extends this to energy, stating that energy cannot be created from nothing (ex nihilo) or destroyed, only transformed from one form to another. In modern physics, Albert Einstein’s mass-energy equivalence equation, E = mc², unified these two ideas. This tells us that mass and energy are different forms of the same thing. In an isolated system, the total quantity of mass-energy remains constant, ensuring the fundamental balance of our physical world Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), Chapter 1: Basic Concepts of Environment and Ecology, p. 14.

Beyond simple conservation, we also look at how elements decide to combine. The Law of Constant Proportions (or Definite Proportions) states that a chemical compound always contains its component elements in a fixed ratio by mass, regardless of where the sample came from. For example, whether you take water from a glacier or synthesize it in a lab, the mass ratio of Hydrogen to Oxygen in H₂O is always approximately 1:8. This distinguishes it from the Law of Multiple Proportions, which explains how the same two elements (like Carbon and Oxygen) can combine in different whole-number ratios to form different compounds, such as Carbon Monoxide (CO) and Carbon Dioxide (CO₂).

Law	Description	Focus
Conservation of Mass	Total mass of reactants = Total mass of products.	Quantity of matter.
Constant Proportions	Elements in a compound are always in a fixed mass ratio.	Composition of a specific compound.
Multiple Proportions	Elements can combine in different ratios to form different substances.	Relationships between different compounds.

Sources: Science, Class X (NCERT 2025 ed.), Chapter 1: Chemical Reactions and Equations, p.3; Environment and Ecology, Majid Hussain (Access publishing 3rd ed.), Chapter 1: Basic Concepts of Environment and Ecology, p.14

4. Conservation of Momentum (intermediate)

To understand the Conservation of Momentum, we first need to define momentum itself. In physics, momentum (denoted as p) is the 'quantity of motion' an object possesses, calculated as the product of its mass (m) and its velocity (v), or p = mv. While we often discuss objects moving in linear motion—that is, moving along a straight line as described in Science-Class VII . NCERT(Revised ed 2025), Measurement of Time and Motion, p.116—momentum adds the critical element of 'heaviness' to that motion. A slow-moving truck and a fast-moving bullet can have the same momentum because momentum depends on both how much matter is moving and how fast it is going.

The Law of Conservation of Momentum states that for a collision occurring between two or more objects in an isolated system (one where no external forces like friction or air resistance act), the total momentum of the objects before the collision is equal to the total momentum of the objects after the collision. This is deeply rooted in Newton’s Third Law of Motion: whenever two objects interact, they exert equal and opposite forces on each other. Because these forces act for the same amount of time, the gain in momentum for one object is exactly equal to the loss of momentum for the other, keeping the 'grand total' unchanged.

Consider the example of a recoiling gun. Before the trigger is pulled, the total momentum of the gun and the bullet is zero. When the bullet is fired forward, it gains a large amount of forward momentum. To conserve the total momentum of the system at zero, the gun must move backward with an equal amount of momentum. This is why you feel a 'kick' against your shoulder. This principle is universal, applying to everything from subatomic particles to the geostrophic winds in our atmosphere that are influenced by various forces but must still obey the fundamental laws of motion Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.), Jet streams, p.384.

Sources: Science-Class VII . NCERT(Revised ed 2025), Measurement of Time and Motion, p.116; Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.), Jet streams, p.384

5. The First Law of Thermodynamics (intermediate)

The First Law of Thermodynamics is essentially the law of conservation of energy applied to thermal systems. At its heart, it tells us that energy is a fundamental 'currency' of the universe that can never be printed out of thin air or destroyed; it can only be exchanged or transformed. In any isolated system, the total quantity of energy remains constant. As established in Environment and Ecology, Majid Hussain, Chapter 1: BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY, p.14, this principle dictates that energy enters an ecosystem (primarily as solar radiation), is trapped by producers, and flows through various levels, changing form but never vanishing from the total balance of the universe. To understand this deeper, we look at the internal energy of a system. If you add heat to a system, that energy doesn't just disappear; it must go somewhere. It either increases the internal energy (making the molecules move faster/getting hotter) or it is used by the system to do work on its surroundings (like steam pushing a piston). This is often expressed by the equation ΔU = Q - W, where ΔU is the change in internal energy, Q is the heat added, and W is the work done. This relationship ensures that the 'energy books' always balance perfectly. In the context of modern physics, this law was further refined by Albert Einstein’s mass-energy equivalence, E = mc². This equation reveals that mass itself is a highly concentrated form of energy. Therefore, even in chemical or nuclear reactions where mass might appear to change, the total sum of mass-energy remains conserved. This fundamental truth means that ex nihilo creation—the appearance of something from absolutely nothing—is physically impossible under our current understanding of the laws of nature.

Sources: Environment and Ecology, Majid Hussain, Chapter 1: BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY, p.14

6. Mass-Energy Equivalence (E = mc²) (exam-level)

For centuries, scientists treated mass and energy as two separate "bank accounts" of the universe. In the realm of chemistry, we rely on the Law of Conservation of Mass, which dictates that matter is neither created nor destroyed; it merely changes form. This is why we must balance chemical equations—the number of atoms entering a reaction must equal the number of atoms exiting it Science, Class X (NCERT 2025 ed.), Chapter 1: Chemical Reactions and Equations, p.3. However, as we moved into the realm of modern physics and the study of the cosmos, Albert Einstein revealed a deeper truth: mass and energy are not separate, but are equivalent and interchangeable.

Einstein’s famous equation, E = mc², provides the mathematical bridge between these two worlds. Here, E represents energy, m represents mass, and c is the speed of light (approximately 3 × 10⁸ m/s). Because the speed of light is such a staggering number, even a tiny amount of mass (m) can be converted into a colossal amount of energy (E). This principle is the engine behind the stars and the fundamental reason why nuclear power is so potent compared to chemical reactions Environment, Shankar IAS Academy (ed 10th), India and Climate Change, p.311. In high-energy events, such as the merger of black holes billions of light-years away, massive amounts of matter are converted directly into gravitational waves, which ripple through the fabric of space-time Physical Geography by PMF IAS, The Universe, The Big Bang Theory, Galaxies & Stellar Evolution, p.6.

The most profound implication of this equivalence is the Law of Conservation of Mass-Energy. It states that the total quantity of mass-energy in an isolated system remains constant. You cannot create mass from "nothing" (ex nihilo), nor can energy simply vanish; they can only transition between one another. While a chemical reaction might absorb energy (endothermic) to break bonds Science, Class X (NCERT 2025 ed.), Chapter 1: Chemical Reactions and Equations, p.10, the "lost" or "gained" mass is so infinitesimal it is ignored in chemistry. In nuclear physics, however, this mass-energy exchange is the star of the show.

Feature	Chemical Reactions	Nuclear/Relativistic Reactions
Primary Law	Conservation of Mass	Mass-Energy Equivalence (E = mc²)
Transformation	Rearrangement of atoms	Conversion of mass into energy (or vice versa)
Energy Scale	Low (Electron bond changes)	Extreme (Nucleus changes/Spacetime events)

Sources: Science, Class X (NCERT 2025 ed.), Chapter 1: Chemical Reactions and Equations, p.3, 10; Environment, Shankar IAS Academy (ed 10th), India and Climate Change, p.311; Physical Geography by PMF IAS, The Universe, The Big Bang Theory, Galaxies & Stellar Evolution, p.6

7. Solving the Original PYQ (exam-level)

Now that you have mastered the fundamentals of thermodynamics and atomic theory, you can see how the physical world operates under strict constraints. The phrase "creation of something from nothing" (ex nihilo) is a scientific impossibility within a closed system because it violates the most fundamental ledger of the universe. This concept brings together your learning on the First Law of Thermodynamics and the Law of Conservation of Mass, which you previously studied as separate entities but are unified here. As noted in Environment and Ecology, Majid Hussain, this principle ensures that while energy can change form, the total quantity remains constant.

To arrive at the correct answer, conservation of mass-energy, you must apply the reasoning that mass and energy are interchangeable. If "nothing" exists, there is zero mass and zero energy; for "something" to appear, mass or energy would have to be generated spontaneously. However, the mass-energy equivalence ($E=mc^2$) tells us that the total sum must be preserved. As emphasized in Science, class X (NCERT 2025 ed.), matter is neither lost nor gained even during complex chemical transitions. Therefore, the appearance of matter from a void is a direct contradiction of this universal balance.

UPSC often includes distractors that are valid scientific laws but apply to different contexts. Options (A) constant proportions and (C) multiple proportions are common traps; they govern the ratios and compositions of elements within chemical compounds, not the fundamental existence of matter itself. Similarly, (D) conservation of momentum relates specifically to the motion of objects and the forces acting upon them. Always ask yourself if the law in question governs the 'quantity of existence' or just the 'behavior' of what already exists. Only the conservation of mass-energy addresses the very existence of matter and energy from a foundational level.