"The Earth in the Cosmos"

Photo by NASA on Unsplash

Whether or not we realize it, most of us, and most people in the whole world live their lives in a very small bubble. We focus on ourselves, on our work, on our families, on our friends and sometimes on our community. Some people expand their world to include their country, and sometimes they even pay attention to what is happening around the world. Living in this small bubble is not a bad thing. It is totally human to do this. It is built into our being through eons of evolution that has enabled humanity to survive in a harsh and often dangerous world.

Taken to the extreme, however, this narrow focus can make a person selfish, egotistical and narcissistic. We all know people like this and, unfortunately, we see these traits in leaders around the world and in America at large. We see it in people we know. We see it in our communities and in the organizations we may be a part of.

Because all of us live in this limited bubble, people forget they are part and parcel of a magnificent creation. Everything we see and know in our world, and earth itself, is but a minute speck in the vastness of time and space. Failure to step back sometimes and realize this is a major factor in making a person selfish, egotistical and narcissistic. Putting our lives and our world in perspective is a sure way to become more humble, more grateful, more in awe of our lives and probably more spiritual too.

So, for a few moments this morning, I want to take you on a journey that will hopefully put everything in a greater perspective and perhaps enable you to realize how amazing and special our existence and your life is. This journey has been made possible by the brilliance and incredible work of countless men and women scientists who have devoted their lives to exploring why we are all here and how our universe came to be.

So let us begin.

Somewhere around 13.8 billion years ago the universe came into existence. Based on recent findings from the James Webb telescope, however, some scientists believe the universe may be older – perhaps 26 billion years old.

In any case, before the universe came into existence, there was nothing, and I mean – “no thing.” This is a hard concept to grasp because not even nothing existed: no time, no space, no void, not even nothing.

For reasons that have been scientifically, philosophically and religiously debated for centuries, somewhere between 13.8 and 26 billion years ago, something happened that caused space and time to expand outward from an incredibly dense area. With it came energy and eventually matter.

This is called “The Big Bang,” but scientists no longer think it was a huge explosion. This initial observable universe was incredibly small, maybe the size of a pinhead, called a singularity, yet it contained everything that is in our universe today. You can actually hear remnant energy from the Big Bang on a poorly turned radio or TV. When you hear static on a radio or TV, some of this noise is from the Big Bang.

It was at the moment of this expansion of the new universe that space and time were created. Space moved very quickly outward after the moment the expansion began. Outside of this new space there was nothing – not nothing. Seconds after the expansion began, there was tremendous heat beyond anything you can imagine. Within a few seconds of the Big Bang, electrons and subatomic particles formed. Some had a positive charge, and some had a negative charge. This was matter and antimatter. Well – when matter and antimatter come in contact with each other, they annihilate each other in a violent explosion.

If there was the same amount of matter and antimatter in the early universe, it would have destroyed itself immediately. But there was just a little more matter than antimatter, so our universe was made possible. Then, about 380,000 years after the Big Bang, the universe had cooled enough to allow the formation of hydrogen and helium atoms. Stars are made mostly of hydrogen and a little helium.

Somewhere around 200 million years after the Big Bang, giant stars began to form, consisting of hydrogen and a little helium. These stars were huge – probably up to 300 times the size of our sun. They had intense gravity which caused hydrogen atoms to collide in nuclear explosions, creating more helium and a few of the elements.

These nuclear explosions created heat and light. The stars were so huge and their gravity so strong, they burned through their hydrogen relatively quickly, meaning they did not live very long – probably only around a million years or so – which is a short life for a star. They mostly ended their lives in massive supernova explosions which is how large stars end their life. These supernova explosions created all the elements we know of. This includes the atoms and elements in your body. As the astronomer Carl Sagan used to say, we are all made of “star stuff.”

Slowly, gravity had an effect on stars and caused them to coalesce into huge islands of stars, called galaxies. Galaxies contain a few hundred million to 400 billion stars. Our galaxy is called the Milky Way – named because of what looks like a band of fuzzy haze on a clear night. Actually, when you look at this band it is really made up of so many very distant stars, it just looks like a haze. You can begin to see individual stars with just a pair of binoculars.

Depending on the season, when you look at this band, you are looking toward the center of our galaxy or outward toward the edge. Our galaxy contains 200 to 400 billion stars From afar, it would look that two dinner plates, on top of the other. The stars are in our galaxy are in spiral bands, hence our galaxy is called a spiral galaxy. Our solar system and earth are located in a non-descript part of our galaxy about two-thirds out from the center.

There are also two small companion galaxies orbiting our galaxy. These small galaxies are in the Southern Hemisphere. They are called “The Magellanic Clouds” because they were noted by Magellan in his round-the-world voyage in the early part of the 16^th century. They appear as clouds, but they are made up of stars that look like clouds because there are so many stars and they are so far away. Each has upwards of 30 billion stars. The view from these galaxies of the Milky Way galaxy must be pretty spectacular!

Our galaxy is over 100,000 light years across – meaning it takes light 100,000 years moving at 186,312 miles per second to traverse the galaxy. The nearest big galaxy to our Milky Way is the Andromeda galaxy – also a spiral galaxy. It is two million light years from our Milky Way. BTW – the nearest star to earth is a triple star system – in the constellation of the Centaur in the Southern Hemisphere. These stars are roughly 4.2 light years away. Just to give you an idea of distance, a spaceship moving 500,000 MPH would take 5900 years to reach these stars. It would take the same ship more than 3.4 billion years to reach the Andromeda galaxy. (What’s really weird is that time on the spaceship would slow down!) Our universe is a really big place.

Astronomers guesstimate there are some two trillion visually observable galaxies in the universe, each containing upwards of 400 billion stars. The number of stars in the known universe is very hard to fathom. But there are more stars in the known universe then there are grains of sand on all the beaches of the world combined. In fact, for every grain of sand on all the beaches of the whole world combined – there are 100,000 known stars.

The galaxies are all moving outward, away from each other because of the Big Bang expansion. So too is space moving outward. Beyond the edge of space there is nothing – not “not nothing.”

There are two very mysterious forces that are exerting forces on our universe, but scientists do not know what they are. One is called dark matter because of its gravitational effect on galaxies and the universe. Scientists know dark matter exists because they can measure its effects, but they can’t see it. Dark matter makes up 85% of the matter in the universe. The other force is dark energy which is causing the galaxies and space to move outward at a faster and faster rate. Scientists can measure it, but they do know what it is.

Despite this, recent and cutting-edge research now points to the outward expansion of the galaxies and space gradually slowing and reversing into a “giant crunch.” Current estimates suggest this will begin happening in 20 billion years.

Within each galaxy are countless clouds of hydrogen left over from the formation of the galaxy. These are stellar nurseries where gravity acts on areas of hydrogen to coalesce it and form new stars. With a pair of binoculars, you can see a very active stellar nursery. If you look at Orion’s Belt (in the winter), below his belt is his “sword.” Just below his belt is a very fuzzy patch. This is a hydrogen gas cloud, and it is a stellar nursery where new stars are forming.

Somewhere around 4.6 billion years ago, our star formed in a stellar nursery. The left-over debris orbited our star and coalesced into 8 known planets and the dwarf planet Pluto, plus a bunch of comets, asteroids and meteors. Among the planets, earth formed about 4.5 billion years ago. At that time, earth was a molten hell with volcanoes everywhere and constant bombardment from meteors and asteroids. There was no moon. There was almost no atmosphere around the earth at that time.

Then about 500 million years later, earth began to cool. Water formed from chemical reactions on earth and from asteroids and meteors which pounded the earth. A smaller planet named Theia collided with earth around this time. The collision destroyed Theia. Its remnants formed a ring around earth which gravity coalesced into our moon.

Life on earth, as we know it, could not have existed without our moon. The collision of Theia created a magnetic field on earth which protects the earth from the sun’s radiation. The moon also slowed the earth’s rotation which permitted more stable climates and a tide which is essential for life in the oceans, and life began in the oceans.

Early earth had the right chemical ingredients for life to form. After there was sufficient water around 3.8 to 4 billion years ago, life emerged quickly.

Early Earth and Microbes

• 2.4 Billion Years Ago: Cyanobacteria start making food from sunlight (photosynthesis), filling the air with oxygen.

Complex Life and Animals

• 600 Million Years Ago: Simple multi-celled animals, like early sponges and worms, evolve.

• 540 Million Years Ago: The Cambrian explosion brings a fast increase in ocean life, creating creatures with shells and hard bodies.

• 475 Million Years Ago: The first green plants move onto the dry land.

• 360 Million Years Ago: Four-legged animals (amphibians) walk onto the land, and large forests grow.

Dinosaurs, Mammals, and Humans

• 250 Million Years Ago: Pangea forms, followed by the "Great Dying" mass extinction. (One huge continent).

• 230 Million Years Ago: Dinosaurs appear and become the main land animals.

• 200 million years ago – Pangea breaks up and the seven continents are formed

• 66 Million Years Ago: A giant space rock hits Earth, wiping out the non-avian dinosaurs.

• 2.5 Million Years Ago: Early human ancestors (Homo) appear.

• 300,000 Years Ago: Modern humans (Homo sapiens) emerge.

About a million years ago, before homo sapiens evolved, our early humanoid ancestors almost went extinct due to climate change. At one point there were only about 1300 humans left on earth, but they somehow survived.

Human agriculture started about ten to 12,000 years ago, and it started independently in many locations around the world including Europe, Africa, Asia and the Americas.

Agriculture forces people to live together in a community instead of migrating around to hunt and gather food. This jump-started civilization which first began in the middle-east around 6000 years ago. This is about the time when we can begin to piece together human history from ancient ruins, writings, archeology, and physical artifacts.

Up until the 1990s, scientists thought that planet formation around stars was very rare. Some thought it was an anomaly and our solar system was one of a kind. This has been proven quite wrong in the last 25 years. By measuring the wobble of distant stars, astronomers can tell if a planet is orbiting a star. The first “exoplanet” was discovered in 1992. Since that time, 6300 exoplanets have been discovered around stars. Scientists now think most or all stars have planetary systems.

So far, about 45 exoplanets have been discovered that may have the right conditions to support life. They are of a size where gravity is not too much or too little. They orbit their star in a “goldilocks zone” which means their temperature is not too hot and not too cold. They have the right conditions to have water. Recently scientists have been able to analyze the atmosphere on some of these exoplanets. They have discovered chemicals in some of their atmospheres that may be produced by living organisms.

The nuclear reactions in stars force outward pressure on a star. But when huge stars burn through all their hydrogen gravity begins to take over and the star collapses. This may cause a huge supernova explosion which, as I mentioned before, creates all the elements we know of. Eventually, if the star is massive enough, it totally collapses into a black hole where the force of gravity is so strong that not even light can escape. Time itself stops. Space is destroyed. Our science cannot explain this phenomenon, and we truly do not know where everything goes in a black hole.

The universe has been around a long time, and it is big, really big. The number of stars in the known universe is beyond what the human mind can comprehend. A question that scientists and a lot of people ask is simple. Why is there life on earth? And why intelligent life? Is this just an anomaly or is this common throughout the countless stars in the universe? A majority of scientists today do believe there is other intelligent life in the universe. A simple but mind-boggling statistic is this: If one ten-thousandth of one percent of all the stars in the known universe had intelligent life on planets around them, there would be 20 trillion intelligent civilizations. If there are 100,000 stars in the universe for every grain of sand on all the beaches of the world, then there are probably

a million planets for every grain of sand on all the beaches of the world. So – do you think life and intelligent life exists elsewhere? The answer has to be yes for sure.

We have been looking for other intelligent life by listening for radio traffic. Our television and radio signals travel at the speed of light. Radio has been around for 120 years so if someone is listening on a planet less than 120 light years from earth, they could detect us. So far, we haven’t heard from anyone.

In any case, given the vastness of the universe and the incredible circumstances over billions of years that created stars and galaxies and planets and eventually the earth, and then enabled life to begin and eventually humanity – isn’t it all a marvelous thing? And in the continual unfolding of humanity, just the right happenings and coincidences occurred to make our own life possible. It all seems almost impossible, but it wasn’t.

I think of this often and it informs my spirituality. I cannot help but think there is some force or power imbedded in the creation of the universe. I do not see this as the Biblical god but something much more fantastic and impossible to comprehend. Some have suggested it is a consciousness, a power imbedded in all things. Perhaps so, but I simply cannot see the incredible harmony and order and creativity in the universe and believe that this is all just a random chance happening. To me, it is all too perfect to be a coincidence, and a lot of scientists agree with me.

I also know that physicists have suggested that because of universal constants that are at work throughout the universe—like the speed of light, and the mass and charges of electrons and protons—the universe is indeed fine-tuned to exist.

I am humbled by studying all of this. Too many people are so focused on themselves, their ego and their hubris that they cannot see the forest through the trees.

Buddhism stresses the importance of mindfulness, and I think this is a great practice because when someone practices mindfulness, it is a humbling experience. Through mindfulness, one can begin to see the incredible magic and mystery that has made our own life possible, and it is something to be very grateful for.

As astronomer Carl Sagan once said, “"We are the local embodiment of a Cosmos grown to self-awareness. We have begun to contemplate our origins: star-stuff pondering the stars."

And as Nobel Prize winning physicist Edwin Schoedinger said, “The totality of observable phenomena constitutes a single universal reality. There is no essential difference between the various parts of it, which we call living or inanimate organisms. The separation between me and the rest of the world is an optical illusion of our state of consciousness."

Reverend Christopher McMahon

August 2, 2026