What do the Bible and neuroscience say about seeing? An exploration of the physical and spiritual sense of seeing.
Let there be Light: The First Spoken Creation
The science and Scripture behind the wonder of light.
In a series of articles about the human senses and perception, it may seem strange to include a whole article on light. Light, of course, is the stimulus for sight and this is the first of two articles: the second being on the science and scripture of vision, which will follow. Light is a fascinating subject in itself and understanding the nature of light can help us understand God’s creation at its fundamental level. Light is mentioned repeatedly in the Bible and depending on the particular translation, it’s mentioned some 270 times. It’s not just the quantity of mentions but quality too as it’s used to represent some profound aspects of our faith.
The first mention of light is highly significant and occurs in the very first verse of the Bible. In fact, it’s the first recorded utterance of God, “Let there be light.” (Genesis 1:3). Light was created before the Sun, Moon, and stars (Genesis 1:14–16) initially to dispel darkness but it occupies a fundamental place within creation itself. Light is not just a physical entity but a primary metaphor for God’s presence, truth and life. By understanding the science of light as a physical phenomenon, we can gain a deeper appreciation of God’s precision of design down to the level of the very fabric of creation upon which everything is built.
The science of light has taxed, and continues to confound, the greatest scientific minds who ever lived. Light is a fundamental part of a branch of science called quantum mechanics which is the science of sub-atomic structures. Light is made of photons that travel at such a tremendous speed that it forms the cosmic limit, and its role in photosynthesis gives animals sustenance. If you don’t have a science or physics background do not despair at what follows. Quantum mechanics is a great leveller as no one, not even the keenest physicist minds, completely understands it.
What is known is that physical matter is made from atoms. The word atom comes from the Greek atomos meaning indivisible or uncuttable. The concept of every object being made up of atoms is not new. It dates to 5th century BC Greek and Indian philosophers, but it was only in 1803 that the English chemist John Dalton put atomic theory on a scientific basis showing that atoms were the building blocks of matter.
In 1897, the British physicist J.J. Thompson discovered the electron, an electrically charged component of the atom. This discovery was only the start of a relentless journey that stripped down the atom to more of its component parts. Protons were the next to be found, then neutrons. Throughout the 20th century, quantum subatomic particles were found. Quantum can be thought of as a “packet” or elementary particles that cannot be broken down any further. Essentially, quanta were the new atoms. There are some 17 fundamental quantum particles that form the so-called Standard Model of matter.
At this point, you may be thinking you’ve read more than your fill of physics. As a Catholic scientist, I look upon these fundamental quantal packets as part of God’s creation which up until now have been hidden from our view. An analogy is lifting up a rock and being fascinated by what’s hidden underneath. Through these new findings, God invites us to explore, grapple with and understand creation in its fullest glory and range, both from its enormity in the firmament down to its smallest dimensions.
At this small level, the normal laws of physics break down and nature starts behaving in strange, counter-intuitive ways. For instance, particles can exhibit opposite behaviours at the same time; can exist in multiple states or locations simultaneously; can be affected by whether we observe what’s happening or not; and form invisible connections with each other even if separated physically across the galaxy. This last state is called quantum entanglement and occurs when two or more particles become permanently interconnected; the physical state of one instantaneously dictates the state of the other, no matter how vast the distance separating them. If you think this is eerie, you’re in good company. Einstein famously called entanglement, “spooky action at a distance”.
Even if physics is not your thing, you can’t help but be equally fascinated and baffled by the behaviour of the very small. The Bible frequently mentions God’s relationship with the smallest of items. Jesus uses an example of a small and insignificant detail to illustrate how deeply God monitors the vastness of the universe, “Even the hairs of your head are all numbered.” (Luke 12:7). A quantum metaphor for God is someone who operates on a cosmic scale also takes interest at a microscopic, individual level.
When Jesus wanted to teach His followers about weighty subjects such as the power of faith and spread of the Kingdom of God, He chose the smallest physical unit familiar with people at the time, a mustard seed, “If you have faith the size of a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move.” (Matthew 17:20). The smallest of objects when activated by divine will can affect the largest of structures.
A Biblical passage which really illustrates physics’ place in faith is, “By faith we understand that the universe was ordered by the word of God, so that what is visible came into being from things that cannot be seen.” (Hebrews 11:3). Millenia before the invention of particle accelerators which evidenced sub-atomic particles, this passage from Hebrews foresaw that visible, macroscopic objects that we can see and touch are built upon a hidden, invisible framework and this has just now been evidenced in quantum mechanics.
As we have seen, light is made of photons and photons are sub-atomic particles whose behaviour and properties are a mystery to science. As Catholics, we embrace mysteries as they offer us an opportunity to explore, struggle, learn, grow and believe. Exploring light and knowing that light was created by God opens us to spiritual illumination.
The Nature of Light — Wave and Particle
Light, paradoxically, is technically invisible when travelling through space. It only becomes visible when it bounces off something physical and strikes the back of your eye. This is why stars look like pinpricks against the darkness surrounding them. Stars radiate light in all directions so logically they should light up the night sky with starlight. However, it is only the light from the star that hits the back of your eye that is registered by us. The rest of the light coming from the star and radiating in all other directions is not visible to us but is there, nonetheless.
The photons making up light are tiny, discrete packets of energy. You would expect these packets or particles to travel in straight lines, but they also move and behave as a wave simultaneously. The discovery of this dual nature of light, particles and waves, was made only recently at the start of the 20th century by two intellectual giants in the physics and mathematics worlds, Max Planck and Albert Einstein.
The Electromagnetic spectrum. Illustration: NASA, ESA, CSA, Leah Hustak (STScl).
What we see as light is only a tiny sliver of what actually exists. Light forms a continuum called the electromagnetic spectrum which ranges across a vast range from radio waves to gamma rays. The tiny part of this spectrum that we can see with our eyes is called visible light. The vast majority of light outside visible light is totally undetectable by our eyes. When we look up at the stars in the sky or when we look through optical telescopes, we see a brilliant array of stars and nearby planets. But when astronomers use radio, x-ray, infrared astronomical devices to detect the light we cannot see, a whole new and different universe opens up creating even more wonder and awe of God’s creation.
Cosmic tarantula nebula. Image Credit: NASA, ESA, CSA, STScl, Webb ERO Production Team.
The mystery surrounding the nature of light has parallels with the mystery around the nature of God. We know light exists, yet we can’t fully understand it. God exists but transcends human understanding. Light is a particle yet travels in waves and similarly God defies simple categorisation. It might seem facile to compare God with light but in the words of John, “God is light, and in Him there is no darkness at all.” (1 John 1:5). As the psalmists sang, “God covers himself with light as with a garment.” (Psalm 104:2). Just as physical light reveals the world around us; spiritual light reveals God. We need both to reveal truth in its fullest form.
The Speed of Light — The Cosmic Limit
I mentioned the speed of light earlier. It’s extremely fast, around 300,000 km/s. Einstein said that nothing travels faster, and it is thought to be the universe’s upper speed limit. As a child, I remember my parents booking a call to Australia from the UK and there would be a delay on the line between caller and listener as you’d have to wait momentarily for the messages to be transmitted back and forth along copper cables. Now, calls are transmitted by light through fibre optic cables or satellites and messages are transmitted almost instantaneously. When I first flew to Australia from the UK it took almost a whole day, and I remember thinking what a vast distance the countries were apart and being awe-struck by how quickly messages must be conveyed between the countries.
Despite the high speed of light, compared to the vastness of space, light seems pedestrian, taking millions of years to reach Earth. Effectively, we are always looking at stars as they were in the long distant past. Stars may have died millions of years ago yet their continued presence as light waves is still making its way to us. Even our closet star, the Sun, is sufficiently far for its light to take 8 minutes to reach us.
God’s use of light and its properties to represent spiritual illumination can also be used as a metaphor for immediacy, connection and omnipresence in the world and through His word. “His splendour was like the sunrise; rays flashed from his hand, where His power was hidden.” (Habakkuk 3:4); and “God’s glory shines in our hearts to give us the knowledge of God’s glory.” (2 Corinthians 4:6). Just as light reaches the ends of the earth instantly, God’s truth and presence are not limited by distance or time.
Light and Life — Photosynthesis and Vision
In the story of creation, God produced the plants on the third day, “God said, ‘Let the earth produce vegetation: seed-bearing plants, and fruit trees on earth, bearing fruit with their seed inside, each corresponding to its own species.’ And so it was.” (Genesis 1:11). Light needed to come before plants to provide them with the energy for photosynthesis. I’m not a botanist but I do remember having to memorise all the complex chemical reactions that are triggered when sunlight lands on plant leaves. In-between having to commit these reactions to memory for exams, I was staggered by how light energy is captured by relatively simple organisms that produced oxygen and food, both of which we need to live and thrive. However advanced and haughty we may feel as a species, without light and plants, our food chain collapses and we are blind.
On a physical level, we are co-dependent on other life around us. On a spiritual level, we need sustenance and feeding too, all of which ultimately comes from God. The Early Church Fathers said of John 1:4–5 in their commentaries, “In him was life, and the life was the light of men.” using it to explain the relationship between God and humanity. Again, from John, “I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life.” (John 8:12)
The use of light in these passages is obviously not physical light but the intellectual and spiritual light of truth dispelling the darkness of sin. Just as plants turn toward the Sun and draw their energy from its light, so we are called to the “Sun of Righteousness will rise with healing in its rays” (Malachi 4:2) to draw spiritual nourishment and energy.
The Spectrum — Unity in Diversity
What we see as white light is only produced by the variety of different colours making it up. Whenever we see the array of colours split in a rainbow, it is a sign of both God’s covenant and a revelation of a hidden diversity within unity.
Earlier it was mentioned that light travels as waves. Not all the waves are identical; they differ in their length. In visible light, the different wavelengths give rise to different colours. An object which appears as, say, blue, absorbs all the colours of the spectrum except blue wavelengths which are reflected off the object and enters the eye. How the eye makes sense of all the colours is explored in the next article.
There are so many powerful metaphors that can be drawn from light and the spectrum of colours which comprise it. God is represented by the pure white light and when it passes through the prism of our physical existence, it makes visible the invisible and beautiful multi-layered attributes of the Divine. The idea that there are seven distinct colours in a rainbow is a human construct. Rather, it’s a continuous spectrum, a true continuum without boundaries but a smooth blend through an infinite number of intermediate shades. Likewise, God’s attributes of love, justice, holiness and mercy flow into one another seamlessly.
Sunlight Spread out into a Spectrum, ILLUSTRATION: NASA, ESA, Leah Hustak (STScI). Public Domain
Miraculous Light — Beyond Physics
We have only scratched the surface of the strange properties of light. Photons behave in ways, which if I described them fully here, you would think are far from scientific and bordering on the mystical. There are numerous examples where unexplained light phenomena occurred in the Bible and at some Marian apparitions. Perhaps the best documented solar events occurred in Fatima, Portugal which were witnessed by tens of thousands of people. They could look at the Sun directly without harming their eyes and the Sun appeared to spin rapidly on its axis. Sceptics have dismissed these events as mass hysteria or unusual meteorological conditions. However, there are precedents for unusual light behaviour occurring throughout the Bible.
In Exodus, “No one could see anyone else or move about for three days. Yet all the Israelites had light in the places where they lived.” (Exodus 10:23); and then there was the light that suddenly appeared from heaven that blinded Paul on the Damascus Road (Acts 9:3). One of my favourite passages is The Transfiguration, where Jesus’ face shone like the Sun (Matthew 17:2).
God is the creator and source of light. He can create illumination without a physical source and make light do anything. Explaining the nature and power of light can be seen as a journey from photon to faith. The connection between the two shouldn’t be that surprising as both have the same origin. The physics of light points to a Creator who values order, energy, and revelation in all the senses of these words.
We can reflect on our own lives and see where we can open up to more illumination for guidance, hope and discerning truth, remember the psalmist’s words, “Your word is a lamp to my feet and a light to my path.” (Psalm 119:105) Finally returning to where we started in Genesis with the creation of light, “God saw that the light was good.” (Genesis 1:4)
In summary, we’ve explored the nature of light both as a precursor to vision and to understand what light actually is. The exploration has taken us down the rabbit hole to the quirky world of quantum mechanics. The journey through this strange world gives us an opportunity to explore God’s creation at its smallest level and to learn more about God’s attention to the smallest of detail.
