Breathe out the centre of a star
Take a deep breath in and breathe out, as you exhale meditate on the fact that a part of what you’re expelling from your body was made in the centre of a star that exploded in a supernova ejecting this element into the cosmos, at least 4.6 billion years ago which was when our solar system started to form.
All known life on earth is said to be carbon based and this element makes up 18.5% of our body, which might not seem like much but we’re mostly water and water is constituted from hydrogen and oxygen, however, carbon is absolutely essential to life.
Carbon is a key component of all known life forms due to its unique chemical properties, which make it incredibly versatile in forming bonds with other elements. This versatility allows for the complex molecules necessary for life, including proteins, nucleic acids (DNA and RNA), carbohydrates, and lipids.
A stellar supernova ejects elemental carbon that is essential for all life as we understand it.
Why is carbon so special?
Since carbon is in the news a lot at the moment we thought it would be prudent and timely to do a mini-dive into this element and ask the question, what makes it so special?
Carbon's ability to form stable bonds with many other elements, including itself, enables the creation of a vast array of organic molecules. These molecules can be large and complex, which is essential for the diverse structures and functions required in living organisms. The carbon atom's ability to form four covalent bonds makes it uniquely suited for constructing the intricate and stable molecules that constitute living cells.
Organic chemistry
Organic chemistry is the branch of chemistry that studies the structure, properties, composition, reactions, and synthesis of compounds that contain carbon. This definition is rooted in the historical context where organic compounds were once thought to be obtainable only from living organisms, hence the term "organic." As we consider agriculture the term ‘organic’ in this context is derived from the concept of the farm as a living organism, where all components—soil, plants, animals, and humans—work together in a symbiotic and holistic manner., all driven by the cycle of carbon
Carbon didn’t exist in the very early universe. Within the first few minutes after the Big Bang, the universe cooled down enough for protons and neutrons to form from the quark-gluon plasma. These particles then began to combine into simple nuclei in a process known as nucleosynthesis. The first elements formed were hydrogen (in the form of its isotope deuterium), helium, and small amounts of lithium and beryllium. This period is known as Big Bang nucleosynthesis.
For the next few hundred thousand years, the universe remained too hot for electrons to combine with these nuclei to form neutral atoms. The universe was filled with a plasma of nuclei, electrons, and photons.
Around 380,000 years after the Big Bang, the universe had cooled enough for electrons to combine with nuclei to form neutral atoms. This era is known as recombination, and it allowed photons to travel freely through space, leading to the release of the Cosmic Microwave Background radiation.
With neutral atoms, gravity began to pull matter together to form the first stars and galaxies. The process of stellar nucleosynthesis within these first stars produced heavier elements, including carbon.
The first carbon atoms were formed in the interiors of stars through the process of stellar nucleosynthesis. This involves nuclear fusion reactions that combine lighter elements into heavier ones. For carbon, one of the key processes is the triple-alpha process, which involves three helium-4 nuclei (alpha particles) being fused into a single carbon nucleus. This process requires extremely high temperatures and densities that are found in the cores of stars.
The first stars are thought to have formed a few hundred million years after the Big Bang, so the first carbon would have been created around that time frame. The precise timing is dependent on the formation of the first stars, often referred to as Population III stars, which are thought to have been massive and short-lived, burning through their nuclear fuel quickly and seeding the universe with heavy elements when they exploded as supernovae ejecting these newly formed elements into the universe.
Human respiration and plant photosynthesis are intertwined in exchange of carbon
Take a deep breath…
When we breathe out we expel more carbon dioxide than we inhale as a byproduct of respiration, the biological process by which our cellular metabolism occurs and in our case, is life.
When we inhale, we bring oxygen (O₂) into our lungs as our atmosphere is made up of 21% oxygen. This oxygen is then transported by the blood to our body's cells.
Inside the cells, oxygen is used for cellular respiration, a process that converts glucose and oxygen into adenosine triphosphate (ATP), water (H₂O), and as a byproduct some of the carbon from the glucose which is of course a carbohydrate, is expelled as carbon dioxide (CO₂).
The chemical equation for cellular respiration is:
C6 H12 O6+ 6O2 → 6CO2 + 6H2O + ATP
The carbon dioxide produced is a waste product of the energy conversion process. Since CO₂ is not needed by the body and high levels of it can be harmful, it is transported back to the lungs through the bloodstream.
Finally, when we exhale, we release this carbon dioxide along with some moisture from the respiratory system into the environment. The air we breathe out contains a higher concentration of CO₂ than the air we breathe in because the inhaled air is mostly nitrogen and oxygen, with very little carbon dioxide (approximately 0.04%), whereas exhaled air contains about 4% to 5% CO₂.
To close the loop, the carbon we exhale originally came from the food we consume and the food we consume originally took the carbon in from the atmosphere in the form of CO₂ by breathing we are participating in a cosmic eternal exchange of carbon.
What we breathe becomes plants again.
When we breathe out this carbon dioxide we in theory, are adding to the amount in the atmosphere but in reality this is a closed loop. We are not breathing out any CO2 that didn’t come from our food and our food, be it plant or animal, contains carbon that it took from the atmosphere, originally though photosynthesis.
This part of the cycle of carbon shows us the energy source that drives this cycle and this is the sun, our star.
The journey begins with photosynthesis, a process used by plants, algae, and certain bacteria to capture carbon dioxide (CO₂) from the atmosphere and convert it into organic compounds like glucose. This process uses sunlight as energy and involves the transformation of CO₂ and water (H₂O) into glucose (C₆H₁₂O₆) and oxygen (O₂).
The process of photosynthesis is commonly written as: 6CO2 + 6H2O → C6H12O6 + 6O2. This means that the reactants, six carbon dioxide molecules and six water molecules, are converted by light energy captured by chlorophyll (implied by the arrow) into a sugar molecule and six oxygen molecules, the products.
The glucose produced through photosynthesis serves as a primary source of energy and carbon for the ecosystem. When we consume plant-based foods (or animals that have eaten plants), we are directly or indirectly absorbing the organic carbon that originated from atmospheric CO₂ captured during photosynthesis.
Once inside our bodies, this carbon is utilised through cellular respiration to produce energy, water, and carbon dioxide. During this process, the carbon bonds in glucose are broken, releasing energy stored in those bonds, and producing CO₂ as a waste product. This CO₂ is what we exhale back into the atmosphere, completing the loop
Cosmic and Eternal Exchange of Carbon
Find a quiet moment for yourself and draw in a breath with intention, and as you release it into the world, pause to marvel at the extraordinary privilege bestowed upon you. You are but a fleeting assembly of cosmic dust, a conscious conglomeration of elements birthed in the crucible of stars now long extinguished. For a mere cosmic instant, you are given the profound opportunity to partake in the grand ballet of atoms, a dance choreographed in the fiery hearts of ancient stars.
As you exhale, reflect deeply on the profound symbiosis that binds you to the vast expanse of the universe and every living entity within it. Contemplate the dissolution of boundaries, the fading distinction between your essence and the cosmos, between your breath and the breath of the planet. This meditation is not merely an act of thought but a communion with the essence of existence itself. The carbon atoms that flow from our lips may once have coursed through the veins of towering trees, fluttered in the wings of distant birds, or even sparkled in the eyes of dinosaurs, beings long vanished from the memory of time. In this ceaseless cycle, the boundaries between self and other, past and present, begin to blur, inviting us to ponder our place within the vast web of existence, they will form the wings of dragonflies, become flower petals in far away lands and spend an eon in the ocean, they will become animals that have not yet evolved and perhaps some will even be carried by humanity to other planets as we make new homes in the stars.
With each breath, nurture a sense of gratitude for this intricate tapestry of life in which you are both a spectator and a participant. Recognise the breath as a bridge between the microcosm of your being and the macrocosm of the universe, a tangible manifestation of the interconnectedness that weaves all life into a single, unified whole. In this realisation, find a wellspring of thankfulness for the privilege of consciousness, for the ability to perceive, reflect upon, and cherish the miraculous interplay of matter and energy that animates the universe.
Let this mindfulness remind you that in every moment of existence, you are engaged in a sacred exchange with the cosmos, a continual giving and receiving that binds your destiny to the destiny of all. In the act of breathing, in the simple, yet profound act of living, you are both a witness to and a creator of the universe's ongoing story. Embrace this truth, and let it fill you with awe and a deep, abiding gratitude for the cosmic journey we share.