What is quantum physics?

Quantum physics is a branch of physics also known as quantum mechanics or quantum theory. Mechanics is the part of physics concerned with matter which moves, from tennis balls to cars, rockets to planets. Quantum mechanics is the part of physics which describes the motions of objects at molecular, atomic, and sub-atomic levels. Although quantum mechanics is an extraordinarily successful scientific theory, on which much of our modern lifestyles depend, it is also completely deranged! Why? Read on below…

The history of quantum mechanics

We now know that all matter is composed of atoms. Each atom is in turn made up of electrons ‘orbiting’ a nucleus, consisting of protons and neutrons. Atoms are discrete. They are ‘localised’: either here or there.

Towards the end of the nineteenth century, atoms were rather controversial. In fact, it was a determination to refute the existence of atoms that led the German physicist Max Planck to study the properties and behaviour of so-called ‘black-body’ radiation.

What he found in an ‘act of desperation’ turned him into a committed atomist, but it took a few more years for the real significance of his discovery to sink in. Planck had concluded that radiation is absorbed and emitted as though it is composed of discrete bits which he called quanta. 

In 1905, Albert Einstein went further. He speculated that the quanta are real – radiation itself comes in discrete lumps of light-energy. Today we call these lumps ’photons’.

So quantum physics is usually intimidating from the get-go. It’s kind of weird and can seem counter-intuitive, even for the physicists who deal with it every day. But it’s not incomprehensible though!

Quantum Physics Is Not Magic

Quantum physics is most emphatically not magic. The things it predicts are strange by the standards of everyday physics: they are rigorously constrained by well-understood mathematical rules and principles. So, if somebody comes up to you with a “quantum” idea that seems too good to be true–free energy, mystical healing powers, impossible space drives–it almost certainly is! 

That doesn’t mean we can’t use quantum physics to do amazing things– you can find some really appealing physics in mundane technology–but those things stay well within the boundaries of the laws of thermodynamics and just basic common sense.

Quantum Physics and the Mind: The Co-relation

“I cannot define the real problem, therefore I suspect there’s no real problem, but I’m not sure there’s no real problem.”

The American physicist Richard Feynman said this about the notorious puzzles and paradoxes of quantum mechanics, which is the theory physicists use to describe the tiniest objects in the universe. He might as well have been talking about the equally knotty problem of consciousness. Some scientists think we already understand what consciousness is, or that it is a mere illusion!  Many others feel we have not grasped where consciousness comes from at all.

The perennial puzzle of consciousness has even led some researchers to invoke quantum physics to explain it. That notion has always been met with scepticism, which is not surprising: it does not sound wise to explain one mystery with another. But such ideas are not obviously absurd, and neither are they arbitrary.

For one thing, the mind seemed, to the great discomfort of physicists, to force its way into early quantum theory. What’s more, quantum computers are predicted to be capable of accomplishing things ordinary computers cannot, which reminds us of how our brains can achieve things that are still beyond artificial intelligence! “Quantum consciousness” is widely derided as mystical woo, but it just will not go away!

What is going on in our brains? 

Quantum mechanics is the best theory we have for describing the world at the nuts-and-bolts level of atoms and subatomic particles. Perhaps the most renowned of its mysteries is the fact that the outcome of a quantum experiment can change depending on whether or not we choose to measure some property of the particles involved.

When this “observer effect” was first noticed by the early pioneers of quantum theory, they were deeply troubled. It seemed to undermine the basic assumption behind all science: that there is an objective world out there, irrespective of us!  If the way the world behaves depends on how – or if – we look at it, what can “reality” really mean?

The most famous intrusion of the mind into quantum mechanics comes in the “double-slit experiment.”

Some of those researchers felt forced to conclude that objectivity was an illusion, and that consciousness has to be allowed an active role in the quantum theory. To others, that did not make sense. Surely, Albert Einstein once complained, the Moon does not exist only when we look at it!

Today some physicists suspect that, whether or not consciousness influences quantum mechanics, it might in fact arise because of it. They think that quantum theory might be needed to fully understand how the brain works. Might it be that, just as quantum objects can apparently be in two places at once, so a quantum brain can hold onto two mutually-exclusive ideas at the same time? Is that possible?

These ideas are speculative and unpredictable, and it may turn out that quantum physics has no fundamental role either for or in the workings of the mind. But if nothing else, these possibilities show just how strangely quantum theory forces and propels us to think. The most famous intrusion of the mind into quantum mechanics comes in the “double-slit experiment”. Imagine shining a beam of light at a screen that contains two closely-spaced parallel slits. Some of the light passes through the slits, whereupon it strikes another screen.

Light can be thought of as a kind of wave, and when waves emerge from two slits like this they can interfere with each other. If their peaks coincide, they reinforce each other, whereas if a peak and a trough coincide, they cancel each other out. This wave interference is called diffraction, and it produces a series of alternating bright and dark stripes on the back screen, where the light waves are either reinforced or even cancelled out.

The implication seems to be that each particle passes simultaneously through both slits. This experiment was understood to be a characteristic of wave behaviour over two hundred years ago, well before quantum theory existed.

The “double slit experiment” can also be performed with quantum particles like electrons; tiny charged particles that are components of atoms. In a counter-intuitive twist, these particles can behave like waves. That means they can undergo diffraction when a stream of them passes through the two slits, producing an evident interference pattern.

Now suppose that the quantum particles are sent through the slits one by one, and their arrival at the screen is likewise seen one by one. Now there is apparently nothing for each particle to interfere with along its route – yet nevertheless the pattern of particle that impacts that build up over time reveals interference bands.

The implication seems to be that each particle passes simultaneously through both slits and interferes with itself. This combination of “both paths at once” is known as a superposition state!  Our ability to sustain seemingly incompatible mental states is no quirk of perception, but a real quantum effect!

Perhaps quantum mechanics is involved in consciousness

After all, the human brain seems able to handle varied cognitive processes that still far exceed the capabilities of digital computers. Perhaps we can even carry out computational tasks that are impossible on ordinary computers, which use classical digital logic.

Every line of thought on the relationship of consciousness to physics runs into deep trouble. It is hard to see how a description of consciousness based purely on pre-quantum physics can account for all the features it seems to have.

One particularly puzzling question is how our conscious minds can experience unique sensations, such as with the colour red or with the smell of frying bacon. With the exception of people with visual impairments, we all know what red is like, but we have no way to communicate the sensation and there is nothing in physics that tells us what it should be like.

Sensations like this are called “qualia”. We perceive them as unified properties of the outside world, but in fact they are products of our consciousness – and that is hard to explain. Indeed, in 1995 philosopher David Chalmers dubbed it to be “the hard problem” of consciousness.

The nature and idea of consciousness is very mysterious and has profound importance, with existential, medical and spiritual implications and productivity. Behaviour and functioning of the brain or, in other words, material brain activity is in some way correlated to the consciousness or mental activity. Since it is the most fundamental theory about the matter that is currently available, in efforts to understand the consciousness we can assume that the Quantum theory can be significantly helpful. Various steps and studies have been carried out to achieve the extent of relation of quantum theory to the different neurophysiologic levels of descriptions!  In the past and in the current scenario efforts have been made to adopt quantum theory in different ways that correlate it to consciousness. The concept that this is solely a quantum effect and does not work for a classical case is also discussed. Researchers studied this about the notorious puzzles and contradiction of quantum mechanics, the theory physicists use to describe the tiniest objects in the Universe.

 The bottom line is, the quantum world just doesn’t work in the way the world around us works. We don’t really have the concepts to deal with it.  This problem, it turns out, is not limited to photons. It extends to electrons and protons and other particles as small as or smaller than atoms. Every elementary particle has properties of both a wave and a particle. That idea is called wave-particle duality. It’s one of the biggest mysteries in the study of the smallest parts of the universe. That’s the field known as quantum physics.

Quantum theory is a theory, which in this case means it represents scientists’ best idea about how the subatomic world works. It’s not a hunch, or a guess! In fact, it’s based on good evidence. Scientists have been studying and using quantum theory for a century. To help describe it, they sometimes use thought experiments. (Such research is by far theoretical.)

Tangled up in particles

Quantum theory includes other fantastic ideas. Like that entanglement. Particles may be entangled or connected even if they’re separated by the width of the universe.

Imagine, for instance, that you and a friend had two coins with a seemingly magical connection intertwined. If one showed up heads, the other would always be tails. You each take your coins home and then flip them at the same time. If yours comes up heads, then at the exact same moment you know your friend’s coin has just come up to be tails!

Entangled particles work like those coins. In the lab, a physicist can entangle two photons, and then send one of the pair to a lab in a different city. If they measure something about the photon in the lab such as how fast it moves then immediately one knows the same information about the other photon. The two particles behave as though they send signals instantaneously!  This will hold even if those particles are now separated by hundreds of kilometres.

As in other parts of quantum theory, that idea causes a big problem. If entangled things send signals to each other instantly, then the message might seem to travel faster than even the speed of light — which, of course, is the speed limit of the universe! So that cannot possibly happen.

Interlink between Consciousness, Quantum Physics (Energy) and Beyond

There is an intricate link between behaviour and biology. The biology has been handed over to us from time immemorial. It’s intertwined with our existence. It’s like a historical, codified legacy that we carry to the next generation. We are the baton of the human race and the planet is the medium. Many of these thoughts may be beyond our control – impulsive behaviours for instance – how does one explain that?  We were born free and that seed of thought has been ingrained in our DNAs from eons.

 And we, as in life, came from particles – then it’s no small wonder that at an infinitesimal level we are particles or vibrations and that thrives in a medium of its own.  Probably our man-made dimensions of the good, bad and ugly graduate towards the right and the wrong are too few to represent these states. We will need a medium to talk to ourselves at subatomic levels. This is the mind-body connection. A connection that takes us back into the first form of our being! In this form of being comes in the very quest to introspect that is the Quantum Physics (Energy).