Why do electrons carry a negative charge? This is similar to asking why men are male or women are female. All this has to do with chance, convention, habit, perception or imagery. The particles are said to possess a charge. Any other evocative word in English could have served the purpose just as well. ‘Charge’ is called ‘zaryad’ in Russian, ‘ladung’ in German, and both work well. Benjamin Franklin, in a ‘heads-or-tails’ kind of decision around 1746, dubbed electrons ‘negative’, and this nomenclature got stuck since then. However, the fact that electric current in a conductor occurs due to the flow of electrons, and not protons was established much later. We are therefore made to understand that the direction of electric current is opposite to that of flow of electrons. So in effect, electric current is actually ‘coming’ when we say it is ‘going’. Therefore calling electron as negatively charged is a historical accident by Benjamin Franklin who could have chosen to call it positive as well. But there is no point in repenting about it. Much to our surprise we find that negativity does not just make chance encroachments in our thinking but it is also there by choice of our understanding. We understand the scheme of things in the following way.
Two pieces of matter that are close to each other have less [positive] energy than the same two pieces a long way apart, and we have to spend energy to separate them against the gravitational force that is pulling them together. Since it takes a positive amount of energy to separate the two, gravity must be using negative energy to pull them together. Thus, “the gravitational field has negative energy. Attractions correspond to negative energies and repulsions to positive ones. The energy of an electron in the orbit of an atom is negative. This binds it well to the nucleus creating a stable atom thereby the entire existence. In classical physics “negative energy” results just from where we set the reference point. If it is set at zero, then the “bound” particles need to have energy added to the system to take them to infinity, so they have negative energy. Real life experiences use of negative numbers in many different areas say weather broadcasting. Meteorologist uses negative numbers to show the cold condition of a region like -15˚C. Negative numbers are used to describe values on a scale that goes below zero, such as the Celsius and Fahrenheit scales for temperature. The laws of arithmetic for negative numbers ensure that the common sense idea of an opposite is reflected in arithmetic.
In quantum physics, negative energy leads to imaginary waves, that have a real decaying therefore negative energy is a very real phenomenon. Now the question is how do we realise the negative amount of anything say energy for the present purpose. Our intuition tells us that energy must always be a positive quantity, i.e. some value we can measure and realise. Quantum physics has however time and again contradicted our intuition, according to which negative energies are allowed, at least in a certain range of space and time under certain conditions. Of course, this has nothing to do with mystical “over unity machines” that allegedly generate energy out of nothing, as they are repeatedly presented in esoteric circles. “The fact that nature allows an energy smaller than zero for a certain period of time at a certain place does not mean that the law of conservation of energy is violated. In order to enable negative energy flows at a certain location, there must be compensating positive energy flows in the immediate vicinity. Imagine if every single particle is removed from a certain space until nothing is left there. Will it still be possible to extract energy even from empty space? According to quantum physics, it is possible to borrow energy from vacuum at a certain location, like a bank account that can be overdrawn.
Locally, the energy can be less than zero, but like money borrowed from a bank, this energy must be “paid back” in the end. If one rises to think above the constraints of common sense, anything is possible. In other words, everything that can happen, does happen. The concept of negativity can be extended with a great deal of positive approach to our lives. In our living experiences, negativity has been found to be actually vital to our well-being and mental health, according to recent studies. Unpleasant feelings are just as crucial as the enjoyable ones in helping us to make sense of life. Accepting negative thoughts and emotions can actually lead to greater clarity and understanding of our life, argues Rodriguez, a Scientific American, psychotherapist. From mindfulness to writing a journal, a shift in perspective and learning to tolerate strong emotions could improve our personality. Ultimately, we have to accept the rough to make the smooth that much better. Negative events have a greater impact on our psychology than positive ones. Psychologists refer to this as (negativity bias), and it can have a powerful effect on our behavior and decision making. With regard to the role of energy in the end of our story, a universe in which positive energy dominates will eventually collapse in a “Big Crunch”, while an “open” universe in which negative energy dominates will either expand indefinitely or eventually disintegrate in a “big rip”. In the zero-energy universe model (“flat”), the total amount of energy in the universe is exactly zero: its amount of positive energy in the form of matter is exactly cancelled out by its negative energy in the form of gravity. It is unclear which of these models is accurately going to describe the fate of universe.
Dr. Qudsia Gani is Assistant Professor, Department of Physics, Cluster University Srinagar