WHAT IS ENERGY – 1?
Basudeba Mishra
Often it is said that “Energy is the capacity for doing work”. Whenever work is done, energy is transferred, showing that, work is the effect of applied or kinetic energy. Currently unrealized (confined) or potential energy is force. A hammer has potential energy. When force is released by some mechanism – like a hand applying force of the hammer on a rod – it becomes kinetic energy. The effect of kinetic energy is the work done. These three are different states of energy. But WHAT is ENERGY? Before answering this question, we must consider the field. Because energy is invariably associated with the field and there is much confusion about what a field is.
In quantum physics, the interaction of two separate physical systems (such as particles) is attributed to a field that extends from one to the other and is manifested in a particle exchange between the two systems. It is nothing but space, which is the ordered or sequential interval between objects. The other definition of space is the universal base for everything that exists. Everything exists in space and time.
A field is called a mathematical abstraction. There are said to be scalar fields, vector fields, etc. As long as they exist, they are said to be real: we use these abstractions to predict the behavior of an existing object. But mathematics is the quantitative aspect of nature. It only depicts increase or decrease in numbers linearly (addition/subtraction or its variants) or non-linearly (multiplication/division or its variants). A number five or nine is meaningless without associating them with some objects. Even (pi), which is indeterminate, is rounded off to the nearest approximation, for comprehending it. Abstract numbers are not mathematically valid. With $3000 if we can purchase a bike, with $1000, we can purchase 1/3 of a bike. It is mathematically correct, but physically meaningless. There is no equation for the observer. No equation can explain love or the smile on the lips of the beloved. It is not the curvature of the lips.
In particle physics, a field is a physical quantity, represented by a scalar, vector, or tensor, that has a value for each point in space and time. It is about measurement of objects and forces in the field, and doesn’t answer: What is Field? Besides, the validity of a mathematical statement is judged by its logical consistency. Tensor is logically not consistent – hence not valid. I have written about it in detail on many occasions.
In quantum field theory, there are said to be two fields: the electromagnetic field and the “electron field”. These two fields are said to continuously interact with each other, transfer energy and momentum, and create or destroy excitations. This is about the mechanism of interaction in a field. It doesn’t answer: What is Field? It is said that, something called an electron field spreads thinly throughout space. According to quantum mechanics, ripples of the electron field get tied up into a bundle of energy. This bundle of energy is called an electron. This is slightly confusing. What are these bundles of energy? It is the protons in the nucleus that radiate out. These are confined by the “electron sea”. The point at which the tip of the radiation is stopped, is the electron. The stress generated by the radiation on the “electron sea”, is its mass. Magnetic fields are produced by moving electric charges. Since the electrons are tiny moving charges, a small magnetic force is created around each atom and the field is called a magnetic field.
Most physicists have concluded that the universe with all of space, time, and matter, is made of fields. These fields have no smallest, indivisible constituent – hence not quantized. But in QFT, it is said that quantum fields are not generated by “matter”. Instead, “matter” itself is considered as a quantum field, which is made up of particles. Every particle is said to be a field. “Matter” is said to mean a field of fermions (such as electrons or quarks), whose excitations describe (probably fermionic) matter particles. Bosonic fields describe forces acting on and between the fermions. The universe is full of fields. What we think of as particles are nothing, but excitations of the fields – like waves in an ocean.
This description misses the forest for the trees. It talks of waves, but ignores the ocean. Without the ocean, there can be no waves. Without fields, there can be no particles. The matter is like players and the forces like the force they exert on the ball. For example, an electron is an excitation not of, but in an, electron field. Everywhere we find particles occupying fields. The laws of physics is same everywhere. It can’t be different here without any justification. Due to such wrong interpretation, in the Standard Model, the number of fields is said to be 17 (6 quarks, 6 leptons, photons, two W and one Z bosons, and the gluons). In the Standard Model including all gluon colors, the number of fields is 24 (12 fermion fields and 12 boson fields).
The Higgs boson is said to be a fundamental particle associated with the Higgs field. It is said to be a field that gives mass to other fundamental particles such as electrons and quarks. All fundamental particles do not have mass. A particle’s mass is said to determine how much it resists any change in its speed or position when it encounters a force. This explains the effect of mass when a force interacts with the body. It doesn’t explain what is mass.
Mass measures the stress generated by a body on its base due to its relative density compared to its volume or composition (both number of primary components and nature of the bond). Thus, it depends on the nature of confinement of the object – the more compact an object, the more it’s mass per volume. We measure mass by weight or by comparing density with volume. Unless we place the object on a balance directly or through a container, we can’t measure its weight – hence mass. For liquids and gases, volume is measured and density is calculated from the density table, which is expressed in units of g/ml (one gram is defined as the mass of 1 cc of water). It is said that weight is mass multiplied by acceleration due to gravity – g. If a stone weighs 1 kg on Earth, it will weigh (1kg/9.81m/s^2) * 1.622m/s^2 on the Moon. This is a wrong description. For proper comparison, we must take the unit 1kg weight to the Moon. There, the g of Earth 9.81m/s^2 will cease to exist and will be replaced by 1.622m/s^2 of the Moon. Hence, the weight will be 1 kg only. Multiplying both sides by g, or dividing and then multiplying the unit by g, is superfluous.
A field is a region of space, upon entering which, we experience a force. Based on the nature of the force, we name the field. For this reason, they talk of Field forces: Gravitational force, electrical force, magnetic force, and electro-magnetic forces etc. Earlier we said, force is potential energy. It has to be released by some mechanism. Released force that moves objects, is energy. It is wrongly said that the field tells us what the force would be on a particle with a charge of 1, if such a particle was there. Force is related to whatever particle is there in the field. The field itself is inert.
Consider a football field. If you keep a football in a field, it doesn’t become a football field. At least two players must hit the ball towards specific directions to call it a football field. By changing the players and the ball, you can call it the hockey field or basketball field. In all this field remains constant. The players, the forces applied by them and the balls change. This is the universal definition of field. That which contains everything and acts as the base, is The Field. That which moves in the field moving others, is the energy.
Force fields (gravitational, electric, and magnetic) are really fields containing energy that can be transmitted across space from one object to another. When two objects interacting through a force field are said to change their relative position, it is really the energy stored in the force field that is changed – not the field itself. During singularity, energy goes into potential form. Then, the field and the force become indistinguishable. Without motion, we can’t perceive anything.