“We have discovered life, or evidence of life, on seven of these systems. Primitive. Not advanced beyond the level of microbial or single-celled life we see on Sol system. On three of these systems, life has been extinguished. We only find fossilized remnants. Seven out of thousands is not too bad, though. The further we reach into the void the better the odds of discovering a kindred soul among the stars waiting on us.”
“Who among you is familiar with the Drake equation?”
Hands go up all over the class.
“Sister Hansler, please tell us what the Drake equation is.” “Yes, Abbess.” Sister Hansler stands and faces the class.
“The Drake equation is famous. It is a measure of the probability of life in our universe. Intelligent life, rather. It is usually used in the context of calculating the probability of life in the universe within a volume of space or an area of influence.”
“Very good, sister.” The Abbess smiles, and Hansler returns to her seat.
The Abbess walks to the rear of the class. “In the twentieth century, two very famous scientists tried to arrive at the odds or probabilities of life out there in the cosmos other than on Sol system. Frank Drake and Enrico Fermi. Their discussions and talks on the subject developed the very famous Drake equation and the equally famous Fermi paradox.”
“The Drake Equation contains seven variables. The number of stars being formed, the number of stars that have planets, the percentage of these that can host life, the percentage of those that develop life, the percentage of those that develop intelligent life, the percentage of those intelligent life systems where they learn to communicate in a manner we can detect, and the time that these civilizations would survive themselves.”
“It’s pretty straightforward as equations go. Multiply each times the other. I myself can run the math.” The Abbess smiles and the class chuckle with her.
“When I run the math, I arrive at a probability of 100% for intelligent life if we look at a large enough sphere. In particular, my sphere reaches 100% probability at around 1,500 light years volume.”
“Since we have expanded into a sphere over 1,250 light years in volume, there is a really good chance we have already reached far enough to find them. We just have to look real hard now.”
“Hansler, please tell me about the Fermi paradox.” “Yes, Abbess.” Hansler stands again.
“Enrico Fermi famously calculated the Drake equation and determined that the universe should be full of life. “Where is it though?” He asked his contemporaries, including Francis Drake himself. Fermi calculated that our own Sol system should contain alien artifacts from visitors. He also calculated that we should see evidence of them in the sky, in their radio emissions, in their light pollution, in their effect on the atmosphere of their planets that we could measure…” Marie slows down and takes a deep breath. “Fermi believed we didn’t see evidence of intelligent alien life because it was rare and improbable. No matter the math of the Drake equation, he knew we were missing something, or we would simply see alien life if we looked for it. This is his paradox.”
Marie takes her seat again with a glowing smile from the Abbess.
“Thank you so much sister Hansler.” The Abbess continues pacing the room. She holds her hands firmly together in front of her chest. “Class, I have some thoughts. They are rational and well thought. I think they are anyway.” The Abbess again smiles. “I believe we live in a Golden Age of Discovery today. That the Catholic faith is on the cusp of finding our brothers and sisters and whatevers…” Again, the smile. “Under foreign suns. I believe we are within the 50th percentile of the Drake equation at the moment, and the meter is moving further to the right for every system we discover, for everybody we view through a telescope, for every radio transmission we scan the sky for.”
“I believe we will join hands and pray with aliens under a foreign sun within my lifetime, and I am no longer a young woman. Most of you will spend some significant time on the Drake equation with Hakham Katz. Study it well students.”
“Dismissed.” The Abbess smiles on the students as they shuffle out of the class. She mentally forces herself to remember all their names and faces. She will remember them all in her evening Vespers prayers.
Chapter Four
Hakham Katz, the Drake Equation
The Year 2432, Catholic University, the Vatican
“Students, welcome to class. As one of the few non-Catholics at University, I would like to introduce myself before we begin.” Hakham Katz leans over the class from his lectern. He is a small statured man, but from the lectern, he appears much larger. He hops off the stool he has stepped on and walks to the front row with a large smile on his face.
“It is my genuine pleasure to meet and have the opportunity to work with and teach all of you this semester. Who can tell me what the title Hakham means?”
Several hands go up. Katz selects the closest student. “You, yes you, young man.”
The student rises and faces the class. “A Hakham is a title of a Jewish religious leader. Not quite a Rabbi, but more than a lay leader. A Hakham may often say prayers instead of a Rabbi. A Hakham may also be responsible for the accounting or other important functions for a Jewish community.”
“Very good, young man.” Katz asks him to sit and he continues.
“My father, and my father’s father before him, worked for the University. They held the title of Hakham before me. It is my hope, my deepest hope in life that one of my daughters will take up the title from the community after I am no longer able to carry the responsibility. We Jews are few in the modern era. Those of us that are left cling to our religion and customs with a vice-like grip however. My family and several other Jewish families have worked with and for the University for over a hundred years now. We number nearly two hundred individuals in the families.”
“It is an interesting story how the Jews and the Catholics have worked together for these hundred years. I encourage you all to attend my history class where we will study the relationship in detail.” Katz walks through the seated students to the back of the room. Unlike his more famous contemporaries, Hakham Katz is not afraid of using modern technology in his classes. He energizes a small device at the rear of the room and the ceiling and front of the class spring to life in swirling stars and star systems. The Sol system is on the front wall in the center. Less than a half meter from it is a three-star system - Alpha Centauri.
“Class, please follow along as we stretch our minds a bit. Like a runner preparing for a race, if you will.”
“Ground Zero is Sol system. The sun. From the sun to the earth is 152 million kilometers. What does that tell us? I’ll answer my own question… It tells us very darn little. It’s just a number. It’s not even a very large number.”
“Intstead, let’s think of this distance in time. Not strictly as a distance. Light photons generated on the surface of the sun leap out at 299,792,458 meters per second. They travel in every direction imaginable. Some head straight for the earth. It takes these photons a leisurely eight minutes to reach us.”
“Another way to visualize it. Pretend the Sun goes Supernova as we sit here. It expands and engulfs mercury and emits enough heat to cook the earth in a second. We’d be doomed for eight whole minutes before we saw it. Light from the sun takes 3 minutes to reach Mercury, five to Venus, eight to earth. The edge of the Kuiper belt is a more sedate 5.5 hours away. It takes this light, these photons a full three years to cross the edges of our solar system into the void.”
“Let’s play a mental game with the help of my fancy device!” Katz laughs as he plays with the control of the projector.
The sun is the only thing visible. A bright dot. Right in the center of the wall. “We have eight planets that roughly frame the elliptic disk of the solar system.” The image adds the eight planets, roughly to scale. The four(Jupiter, Saturn, Uranus, Neptune) Gas Giants dominate the system visually. The image is less than a meter across. “Let’s shrink this down a bit. C
all it one tenth scale.” The image of the solar system shrinks to the point few in the back of the room can make out the detail anymore.
“Let’s add the Kuiper belt now.” The image grows to cover the entire wall. Most of the Kuiper belt objects are still in the plane of the elliptic, but many are not. They orbit above and below the plane of the solar system. The image covers the entire wall. “There is a huge amount of matter in the Kuiper belt. There are 756 bodies large enough to be classified as planets if they were in the inner system. They have cleared their orbit of other debris, they have enough gravity to round their appearance, and many are still warmed internally by the fires of nuclear decomposition deep within their cores, similar to Earth. Liquid magma so far from the sun, that our own sun appears smaller than many other suns in their sky. Imagine that!”
“Let’s adjust the scale again.” The images shrink down to ten percent again. Then it springs back to life. “We added the Oort cloud. All of the comets and randomly detached objects that orbit the sun, thus they are part of our solar system. Look to the right of the wall, what have we here…?”
“Is that a sun?” One of the students near Katz asks.
“Yes, young man, it is. It is indeed a sun. Three suns if you look closely enough. Out past our outer solar system, out past the Kuiper belt and the termination shock and the heliopause. Out at the limits of the edges of our Oort cloud, we have another system. Alpha Centauri. We trade comets and unattached objects with our nearest neighbor from time to time. Often, in the galactic scale of time.
Luyten is the closest star to Alpha Centauri by the way, it is not Sol. Alpha Centauri and Luyten swap comets and unattached objects from time to time as well. We play a long term long distance version of football with our galactic neighbors after a fashion. Objects that may have originated in our system have certainly traveled across the void to Alpha Centauri and from there to Luyten and vice versa. It would take hundreds of thousands and millions of years certainly… but these time scales are nothing to the Galactic scale of things.”
“Let’s condense our Sol system and all the others in a fifty-light year sphere onto the wall.” The wall springs to life again. There are over 2,500 systems on the wall now. “This does not include brown dwarves by the way. We have sent some crews to various brown dwarf systems, by and large, they are not as interesting or as profitable as other systems. Brown dwarfs are hard to find as well. They emit little or no light. Usually, they are discovered from their influence on neighboring systems.”
“Now let’s expand to a thousand light years.” The wall is an undecipherable mess. It may as well be a single point of light. “There are between six and twelve million systems in this volume of space around us. Again, not counting brown dwarf systems.” The image moves a little more. “Here, we are at 1,256 light years, which is where we currently are in mankind’s diaspora into the void.”
“Our Milky Way galaxy is 112,906 light years in diameter. It is 13,200 light years thick at the center. We are on a far edge of an unimportant little spiral arm. On either side of us, there is a void of 1,000 light years to the next spiral arms edge. The galaxy contains 525 to 560 billion solar systems, again, not counting the brown dwarf systems. A few hundred light years above us on the Galactic plane is the void of space between galaxies. We are on the edge of nothingness. The vast reaches of complete nothingness between the Milky Way and the next galaxy from us in the void.”
“Let us discuss the void and our neighbors. Please, someone, tell me our closest Galactic neighbor?”
One of the female students in the rear of the class answers up quickly. “That is Andromeda sir.”
Katz looks thoughtful and asks his follow up question. “Does everyone here agree?” The class is silent.
“Andromeda is the closest spiral galaxy, it is thin on the Galactic scale and has spiral arms, making it a close approximation of our own spiral galaxy. And it is a member of what we consider the local galaxy group, but it is not the closest galaxy to us by far. There are over a hundred galaxies that are closer to us than Andromeda.”
The wall at the front of the class again comes to life. “There in the center is our galaxy the Milky Way, home of everything and everyone you know. Again, we are on the outer edge of an insignificant spiral arm on the right side of the dot, right there if you will.”
Katz points with his laser pointer at the location of our Sol system in the far end of a spiral arm. The graphic on the wall shrinks rapidly. Another dot appears within a meter of the Milky Way dot. “That is Andromeda in all its glory. It has one trillion or more solar systems within its influence. One trillion solar systems. Again, not counting the brown dwarfs. More than twice the size of the Milky Way.”
“Let’s add the rest of the local group. Another hundred and twelve system pop onto the wall. “Sixty-one of these galaxies are closer to us than Andromeda.” They are smaller and less bright certainly. The closest system to us is actually inside the Milky Way!” Katz expands the view to center the spiral arms and galactic center of the Milky Way on the whole wall. “There class, right on the bottom side of the galactic plane just off-center axis is a galaxy taking a leisurely stroll through the heart of the Milky Way. This is the Canis Major Dwarf. This galaxy is closer to the center of the Milky Way than we are!”
“Out on the furthest end of the spiral arm over there.” He points again with the red light from his pointer. “Is another dwarf galaxy plowing through that spiral arm and sucking out hundreds of systems with it. That is Maxoris dwarf four. Let’s bounce back out to Andromeda for a moment though.” The image on the wall shrinks to show just Andromeda now. “Andromeda has a few dozen dwarf galaxies under its local influence. Most of these dwarf galaxies are closer to the Milky Way than Andromeda is.” The dozens of dwarf systems appear around the galaxy, then image then shrinks to show the Milky Way again. The center of the local Galactic group.
“If we expand from the local Galactic group, which is itself 3.25 million parsecs in diameter. Hang on, new term. A parsec is a useful term to describe distance, but only if you understand what it is. A parsec is 3.26 light years. So, make the local group diameter approximately 10,500,000 light years across. Our neighborhood, if you will. Our local group of galaxies is more than ten million light years diameter. Local group. And we aren’t even the most interesting galaxy! By far! Andromeda out masses us by twice our size and has more than twice the systems. There are several dwarf galaxies that contain super massive black holes larger than the one in the center of our system. We are uninteresting and obscure even locally. We are stuck in the back woods of a spiral arm in our own galaxy, and in our local group we are being invaded by two interloper galaxies. And we are stuck out away from the center of the action.”
“Scale is important here.” The local group on the wall shrinks to a dot. “That’s us and our Galactic neighbors in that dot. The local group. We are a part of the Virgo Cluster.” The wall comes back to life. There are hundreds or thousands of galaxies on the wall. “These dots are not galaxies. These dots are clusters of galaxies similar to our own local group. If we expand again, the Virgo Cluster is itself part of a larger group creatively named the Virgo Supercluster. If we look past the Virgo Supercluster, we find superclusters everywhere we look.”
“Our Milky Way is 110,000 light years in diameter. The local group is over 10 million light years across. The Virgo Cluster is over fifteen million light years in diameter. But wait, there is more.” Katz stops and smiles. Several students laugh. “The Virgo Cluster contains fifty times more galaxies than the local group does.”
“The Virgo Supercluster is 110 million light years in diameter and contains 100 more galactic clusters. Remember we are talking about clusters of galaxies here!”
Katz powers off the projector and walks slowly to the lectern again. “Solar system. Spiral arm. galaxy.” He is counting off on his fingers as he speaks. “Local group of galaxies. Local cluster of galaxies rather. Virgo Cluster. Virgo superclusterSupercl
uster.”
“Everywhere you look into the void around us, we can see other superclusters of galaxies. There are billions and billions of superclusters. Each containing hundreds or thousands or millions of smaller local clusters of galaxies, each of those contain dozens or hundreds or thousands or millions of galaxies. Each of those galaxies contains billion or hundreds of billions or thousands of billions of stars.”
“Let’s spend some time looking for life in all that cosmic soup, shall we?”
“The Drake Equation is simplicity itself. We are solving for “N”. First a quick primer.”
The formula appears on the walls and ceiling.
N = R∗ * fp * ne * fl * fc * L
“N is the total number of civilizations, advanced civilizations that are currently in existence and communicating with a mechanism we can understand. Electromagnetic radiation perhaps, or visible light? Tin cans taped to strings perhaps. Or whatever.” Katz seems to be enjoying himself greatly. His smile is contagious and the students are enjoying themselves too.
“R* is the average rate of star formation in our galaxy. Here in the good old fashioned unimportant obscure Milky Way. In the backwaters of our local group, in the backwaters of our cluster, in the backwaters of our supercluster.”
Thomas Aquinas, Explorer of the galaxy Page 6
