The chemical composition of palm branch ash has been analyzed to show that it contains not only carbon from organic material, but also minerals from the soil and its fertilizers. When the palm branches are burned, they leave a powdery residue. This residue is composed of mostly calcium carbonate and potassium chloride, making it chemically alkaline with at pH > 10. Calcium carbonate is the compound found in rocks and minerals, most recognizably in limestone, chalk, and marble. It is also found in pearls and the shells of marine organisms, snails, and eggs.

When our bodies die, the rotting corpse is actually teeming with microbial life. Enzymes digest cell membranes, thereby breaking open the cells. Bacteria feed on the remains and emit gases. Proteins stiffen. The body eventually gives nutrients to the surrounding soil, fertilizing it into an organically rich area. Other organisms feed on the body, such as maggots, insects, and animals, and they transfer the energy stored in the body back to the environment. These may not be pleasant thoughts, but the process of decomposition reminds us that we are dust and to dust we will return.

But that is only part of the story. Take cosmic expansion and primordial nucleosynthesis. There is now evidence that elementary particles expanded from a singularity about 13.8 billion years ago, what Catholic priest Fr. Georges Lemaître termed the “primeval atom” in 1931, which Fred Hoyle later called the Big Bang.

The mathematical relationships and constants involved are striking. In the Planck epoch (the earliest defined quantity of time), scientists think all matter and energy was contained in a dense point a billionth the size of a proton. In 10-43 seconds (a trillionth of a trillionth of a trillionth of a millionth of a tenth of a second), the universe cooled to 1032 kelvin (about three hundred thousand times a trillion times a trillion times the boiling point of water). By one second, protons and neutrons formed, and the universe cooled to 109 kelvins.

Computations suggest that for a long time the universe was 75 percent hydrogen by mass, 25 percent helium, with a small amount of deuterium (hydrogen with 1 proton and 1 neutron), lithium, and beryllium. Hydrogen, helium, lithium, and beryllium are, therefore, the first four elements on the periodic table. Astronomers now measure a slight change, down a bit to 74 percent of ordinary matter in the universe as hydrogen, 24 percent helium, and the remaining 2 percent comprises the rest of the known elements formed by the fusion of nuclei in stars, called nucleosynthesis.

Gravitational forces collapse gases and dust into nebulas. At the dense, hot core, hydrogen nuclei fuse to produce helium and release energy. This is how stars, such as our sun, spend most of their lives. When the hydrogen is nearly gone, the core contracts, its exterior regions cool and emit red light, and the star becomes what is called a red giant. Helium nuclei fuse to produce beryllium. If beryllium collides with another helium nucleus, carbon forms. If carbon reacts with another helium, oxygen forms.

And tada! There is a high abundance of hydrogen, carbon, and oxygen in the universe—the elements necessary for life on earth. As stars cool, the cores become denser and hotter, and the stars become white dwarfs. The heavier elements fuse until the cores are mostly iron. The stars collapse under the gravity until a supernova explosion occurs. Elements heavier than iron fuse in these final—dying if you will—moments of the star’s life.

Matter on earth, the molten core, the crust, and the atoms in our bodies, first formed in stars. A fact of life seldom appreciated is that we will never know what pathways and forms all the matter and energy in our bodies traveled before getting to us, nor will we ever know where every particle and Joule go after we die. Your fingernail very well might contain some ten million atoms, and literally, God only knows where all those particles have been.

Furthermore, the very oxygen we breathe is produced by photosynthesis in chloroplasts that evolved from bacteria. This evolution over the eons generated the oxygen in the Earth’s atmosphere. How? In the chloroplasts (half a million or so per square millimeter) of plant leaves, for example, the chlorophyll molecules in the thylakoid membranes absorb photons from the full spectrum of visible light from the sun. Photon? What is a photon?

Photons are light, discrete quanta whose energy is given by Planck’s constant times the frequency of the wave (E=hf). Protein complexes in the chloroplasts orient chlorophyll molecules at exactly the right angstrom-scale spacing so that when photons excite electrons, the electrons are passed to reaction centers in less than a tenth of a nanosecond with an efficiency of >90%.

Electrons enter a complex system of electron transfer pathways that directs energy for chemical reactions. Oxidized pigment molecules strip electrons off water (H 2 O) to make oxygen gas (O 2 ). Carbon from carbon dioxide (CO 2 ) from the atmosphere, that stuff we exhale, is manufactured into the 3-carbon precursors of carbohydrates. Carbohydrates store energy and form structural components, such as dietary fiber (like when you eat vegetables) and the 5-carbon monosaccharide ribose in the backbone of ribonucleic acid (RNA) and deoxyribonucleic acid (DNA), the stuff of which the language of genetics is written. As the late Nobel laureate Dr. Richard Feynman once said, trees are made from, well, air. I would take it a few steps further. Plants and trees are made from (in part) our breath which comes from our bodies which come from the earth which comes from the stars in the vast cosmos.

Last, this entire, magnificent orchestration swirling in our universe is fine-tuned, according to the best knowledge gained by the most advanced scientists today. As Drs. Geraint Lewis and Luke Barnes, astrophysicists at the University of Sydney and co-authors, put it: “We’ve looked at some of the basic properties of our Universe – the masses of the fundamental particles that make up matter, and the spin of the electron and quarks. We have found that if these properties had been slightly different, the intricate physics and chemistry of our Universe would not exist.” (A Fortunate Universe: Life in a Finely Tuned Cosmos, Cambridge University Press: 2016, p. 63).

So, when you receive that cross of ashes on your forehead, let it be a reminder that we may come from dust and to dust our bodies will return, but the dust comes from the universe held in precise existence since, as far as we can tell, the very beginning of time.