In my earlier blogs I have tried to persuade you that everything in this universe of ours is either space or energy. The concept of energy took a leap forward in science a few hundred years ago when scientists were trying to explain the association between a body’s loss of speed and its friction heat release. The heat released was found to be proportional to the mass of the object and to its lost velocity squared. It gave rise to the idea that a body in motion has an energy store that it gives up as the body slows down. That energy store was regarded as given to the body by the energy that set it in motion.
I think my first learning about energy was at school about 65 years ago when I learnt of potential and kinetic energy and how they could be equated. It seemed the energy of an object was either related to its height above the ground, and called potential energy, or related to its speed of motion and called kinetic energy. My calculations of equating the two were good but my understanding poor.
When helping my granddaughter prepare for GCSE I found her course book saying “anything moving has energy in its kinetic energy store” and describing a gravitational potential energy store as “anything that has mass and is in a gravitational field”. I then found a Faraday Lecturer and numerous science articles all saying much the same thing. It seems it is an accepted view that body’s in motion have an energy store.
Is science right in its thinking that structures have energy stores related to their speed of motion and to their height in a gravity field?
Does it make sense that a book on the top shelf (or at top shelf level) has more energy than the same book when on a bottom shelf? When we are running do we really believe our body cells and their particles have some energy store that they don’t have when we are stood still? Truth is objects don’t have either a potential energy store or a motion energy store. Our calculations may work but our energy model is badly wrong.
The energy thrusts between a car engine’s pistons and its cylinder head are delivered by the burning of fuel in its cylinders. Every bit of the energy released from the fuel is accounted for as in the diagram. The drive energy part that keeps the car moving is needed only because the road and the air offer resistance to motion. The tyres and road and the air and car are warmed by the energy exchanges they engage in. Nowhere on our diagram do we see a car motion or kinetic energy store. If we want to slow the car rapidly we provide an energy interaction (the brakes) to reduce the car’s speed.
Kinetic energy is the interacting energy between structures that causes a change in their relative motions, slowing their approach or speeding up their departure. It is not a speed related energy store!!
At school we learn to calculate kinetic energy using 1/2 mv2. On the right I show how that is derived and you will see it is the energy to steadily accelerate an object of mass m from rest up to a speed of v. The maths confirms what I have typed in bold above – that kinetic energy is the energy that accelerates or decelerates an object, not an energy store.
A firework rocket thrust upward from the earth gains motion relative to the earth. In lighting the rocket touch paper we have input some energy that disturbs its structure giving its particle contents the opportunity to move to a more energy efficient arrangement and releasing mass energy in the form of photons. Some of that photon thrust energy goes into the rocket compressing its particles, adding to their agitation and increasing its internal energy (it gets hot). When the rocket thrust ceases that compression mass energy is soon released to the air as the rocket particles settle in energy. There is no motion energy.
The rocket’s particles are seeking and absorbing energy from their surround; it is what particles do. They are aware of and desire the photon energies emitted by earth’s particles. That gravity desire acts to decelerate them. If at a certain speed all noticeable influences including gravity desire could be switched off the rocket would remain at that speed and its particle positions and mass energy content would be the same as at rest on the earth. However, nothing in our universe is uninfluenced.
However the rocket particle desires for earth’s photon energy emissions are not switched off and they act to slow the rocket and return it to the earth. The height any object reaches above the earth is related to the energy that set its particle structure in motion and the opposing particle desires for earth energy. It is why we are able to equate the supposed potential energy of object height to the supposed energy of motion but neither are true forms of energy.
If a car hits a tree at 5 miles per hour the interacting energy that brings it to a halt in the earth environment is related to 5 squared = 25. If our 5 m.p.h. car collides head on with a 95 m.p.h. train the energy that brings it to a halt in the train environment is related to 100 squared = 10,000. The car doesn’t suddenly have a kinetic energy store 400 times as big because it is encountering the train.
A thermometer placed in a gas is said to measure the average kinetic energy of its molecules but it isn’t. Yes, there is more energy within the molecules of a gas, it is a part of the very nature of being a gas but the thermometer is not measuring such energy because it cannot enter the gas molecules. The thermometer is measuring the interacting photon energies between the molecules which are a part of the energy accommodating state of matter that is a gas.
The theory of relativity and the energies of particles as calculated in the Large Hadron Collider experiments view kinetic energy as a motion energy store but are wrong to do so. The associated mathematics works but the concept is wrong and leads to differences of opinions on what mass is as I will try to explain.
Applying the 1/2 mv2 calculation to known energy exchanges in high speed collisions resulted in velocities in excess of light speed. Something was wrong and 1/2mv2 was only useful deriving the energies involved when object speeds were less than half light speed.
Kinetic energy became ( ϒ -1) mc2 with ϒ, the Lorenz factor and equal to 1/ sq rt (1- v2/c2). It meant energy rises toward infinity as the relative particle speed v approached that of light speed c. Such massive particle energy increases begged the question where is all this energy stored and two schools of thought arose. One decided E = mc2 was only relevant to bodies at rest, that photons had no mass and that the speed energies were extra energies the body had effective in delivering momentum but not a part of mass. The second school of thought assigned mass to photons, and saw energy and mass as always being the same. Total rest energy and kinetic energy could be equated to mass using E = ϒ mc2. ϒm was termed relativistic mass and accounted for the rest energy and motion energy.
My view is that the mass of a structure may vary but it always has an equivalent energy because structure mass energy is the total of its particle mass energies plus the photon mass energies being exchanged by those particles. There is no motion energy. We have wrongly come to think that because energy is involved in changing motion that there is an energy associated with that motion. When structures are being accelerated or decelerated by photon pressures their particles will be pushed closer together and their mass energies will increase but when these interactive photon pressures are removed that mass energy is lost. The energy and mass of an unhindered steady state speed structure are the same as those of a like unhindered rest structure.
Newton saw that like forces make like changes to structure motions irrespective of whether a structure is in a state of rest or state of uniform motion. Einstein argued in special relativity that the physical laws of nature are the same in every inertial frame of reference. By inertial frame of reference he was referring to states of rest or of uniform motion. It would seem to me that both these statements support the idea that the particle arrangements and energy contents of structures at steady speeds are no different to those regarded as being at rest.
It makes sense that we can never push objects to light speed relative to a pushing source because the push from that source is light speed photons. It does not make sense that the energy of an object changes according to its speed relative to an observer. A pushed object may take on added mass due to the push but it does not have a motion energy store.
I hope I have convinced you there is no kinetic energy of motion store and that we should stop teaching children that there is. I wonder if there are any scientists who will accept that this is a serious flaw in science thinking.