HOW BIG IS THE MOON?
(And other questions about life and the universe)
By
Ata Egrari M.D.
©2010 Ata Egrari
All Rights Reserved
First Edition
INTRODUCTION
My name is Ata Egrari. I was a medical doctor for over fifty years, and was continually amazed by the complexity of biology. The intricacy of the body’s construction intrigues me, as does the manner in which our diverse elements and attributes are logically integrated and balanced.
Because of my lifelong fascination and appreciation for the process of birth and reproduction, I decided to learn as much as I could about creation and procreation on the grand scale.
The more I learn, the more I want to know. There is, of course, more scientific knowledge available than any one human being could ever contain.
One barrier to learning about new scientific breakthroughs, or the great scientific discoveries of the past, is the size of the words that scientists often use. Those big words can make things seem more difficult to understand than they really are. You won’t have that problem with this book. You and your friends will understand it and, hopefully, enjoy it.
Yes, some things we’re going to talk about will be basic; other things may be all new to you. Don’t skip the basics.
The explanations in this book require no special knowledge. All you need are two things: the ability to read, and an open mind. The very fact that you are reading this book proves that you are the one for whom it was written.
Join me now on a fun and exciting journey of discovery -– a journey that began for me over seventy years ago on the roof of my grandmother’s home.
Part I
A Universe of Questions
A world of mysteries is a world of discoveries. We have questions, and questions have answers. Not all answers, however, are immediately available. It can take a long time to find an answer.
When I was a little boy, I visited my Grandmother's house where there was a lovely decorative pool in front and a flat roof on top. In the summertime we would have dinner on that roof, enjoying the cool night air and marveling at the clear sky above us
One evening, about seventy years ago, I became so entranced by the bright silvery moon illuminating the night sky that I neglected my dinner. My grandmother had brought dinner to us on a round serving tray. When the plates were removed, and the tray set down, I saw the Moon's reflection in the serving tray. In fact, the Moon fit into the tray perfectly
“Ata,” said Grandma, “why are you not eating your dinner?”
I didn't answer her directly, but instead I asked a question of my own. “Tell me, Grandma,” I asked sincerely, “is the moon the same size as the serving tray?”
"No," she replied. "It is bigger." "How big," I asked.
She thought a while, and then said to me, "it is about the size of the round pool in front of the house."
Grandma, at that time, was fifty years old. What she told me was completely consistent with her true level of knowledge about the moon. For people of her generation, this lack of accurate information was quite common.
In fact, my original question, “how big is the moon?” didn't have an answer any more accurate than the one provided by my grandmother until rather recently. Sometimes the answers to simple questions depend on information that isn't available, or use of a tool or device that hasn't been invented yet.
Eventually I found out that the moon is bigger than both my Grandmother's serving tray and the little pool. The diameter of the Moon is roughly 1/4th the size of the Earth. If the Earth were hollow, you could fit fifty moons inside it. As for the surface of the moon, if you could unwrap the moon so it wasn’t round, it would be a bit larger than Asia.
Earth is about eighty one times as massive as the moon, and it is roughly 60% as dense as our planet. Because the moon has less mass than Earth, the force due to gravity at the lunar surface is only about 1/6th of that on Earth. If you were standing on the moon, you would feel as if you hardly weighed anything at all. If you drop something on the moon, it falls more slowly than on Earth.
The moon is 2,000 miles across, and 250,000 miles from Earth. All these “moon facts” are readily available to any child. All they have to do is ask their teacher, or look it up online. Once upon a time, that was not possible.
More Baffling Questions
Let’s see if you can answer these questions that were once mind boggling mysteries.
Q: What is thunder?
A: Thunder is the sound that lightning makes.
Q: Why does thunder come after the lightning, and not at the same time?
A:: We see the lightning before we hear the thunder because light travels faster than sound.
You probably knew the answers to those questions. If so, it is because you grew up in a world where just about everyone in any civilized country with even a minimal education knows that thunder is the sound that lightning makes, and that light travels faster than sound.
There was a time, not all that long ago, when people didn’t know anything about thunder, lightning, sound or light.
About two thousand years ago, the common belief was that light came out of our eyes. Perhaps they never noticed that they couldn’t see in the dark no matter how wide their eyes were open. Obviously, what they believed wasn’t true, but they didn’t know any better.
The famous mathematician, Euclid, admired for many brilliant observations and discoveries, erroneously believed that our eyes worked like little flashlights. He figured that the reason we could see thing close and far away at the same time was because the light coming from our eyes traveled at infinite speed.
Wrong.
There was no light coming out of our eyes, but Euclid didn’t know that. He was guessing. Good guess, as guesses go, but backwards. In truth, light goes into our eyes, not out of them. Someone, of course, had to investigate and discover, and in time, prove it.
In the 10th Century, the great Iraqi physicist, Ibn al-Haytham (Alhazen), used experiments to support his theory that we see because light goes into our eyes. He even proposed that light had a speed that could somehow be measured. Yes, it was a thousand years after Christ that we first gave serious thought to the idea that light goes into our eyes, not out of them.
Q: When was it first proclaimed that light traveled faster than sound?
A: In the 11th Century, one hundred years later. Another famous physicist, Abū Rayhān al-Bīrūnī, agreed that light has a finite speed, and observed that the speed of light is much faster than the speed of sound.
In the overall time line of life on Earth, the 10th and 11th Centuries were not that long ago. Eventually, over time, other dedicated detectives found ways of measuring the speed of sound, and the speed of light.
Q: What is the speed of sound?
A: It depends. There are things that effect how fast travels sound. The biggest factor is the density of the air. The temperature of the air changes the density.
You may have already noticed that sound travels differently at night on a lake than it does on land in the middle of a hot day. Sometimes voices carry. Those sometimes are when the air density is best for sound speed.
There is sort of a “basic speed” of sound, the true value being about
1116 feet per second. In the dry air when it 20 C (68 F), the speed of sound is 343 meters per second and about 761 miles per hour (1225 km per hour).
The first person to measure sound travel with any accuracy was Sir Isaac Newton. He was off by about 15%, but give him a break. In measuring the speed of sound, he was light years ahead of most people.
The whole “speed of sound” issue is, in a way, amusing. If a tree falls in the forest, and there is no one in the forest to hear it, does it make a sound? That question can stimulate a lively discussion, as does the question, “if a man says something, and there isn’t a woman to hear him, is he still wrong?”
Q: What is sound?
A: Sound is created in the human brain in response to sensory inputs from the inner ear. Any sound you hear is made up of vibrations.
Examples of vibrations would be the strum of guitar strings, or what happens to violin strings when the bow is pulled across them. The vibrations travel through the air until they reach your ear. If you are deaf, you don’t hear a sound. Sound requires both the vibration, and the ability to hear it.
Assuming you have brains, an ear, and there is sensory input, you will experience sound. So, what we are really talking about when we measure the speed of sound isn’t, “sound” at all. We are measuring how long it takes for those vibrations (or disturbances) to travel through the air.
Q: What do we measure when we measure the speed of sound?
A: We measure small disturbances being transmitted through a gas. Air is a gas. The air is the same both before and after the “disturbance” passes through it. The speed of transmission depends on the condition of the gas at the time of the transmission. When there is no air, there is no sound.
In some ways, asking “what is the speed of sound,” is similar to asking, “What is the speed of a car on the road?” Well, it depends on traffic conditions. How dense is the traffic? What is the weather like? If the road is clear and dry, and there is no congestion, you can travel quickly. If there is heavy congestion and freezing rain and black ice, then it slows down. It’s the same with sound. The “traffic conditions” for sound travel are density and temperature.
Now, let’s return to thunder and lightning.
Q: Why does lightning make a sound?
A: Lightning, being a huge discharge of electricity, causes the air to vibrate. Anything vibrating makes a sound. There is more. The lightning is also very hot. This makes the air hot. Heat makes things expand. The air gets real big real quick. This expansion pushes against the air particles and starts another vibration. The rumbling of thunder is caused by the vibration (or sound) bouncing off the ground and the clouds.
Galileo tried measuring the speed of light in 1600. His method was the best he could come up with at the time. He had an assistant stand on a distant field with various shuttered lanterns. The assistant would open the shutters at certain times, and Galileo would try to record how long it took light to get to him from across the field. His only conclusion was that light was really, really fast.
In 1492, Columbus sailed the ocean blue. Almost two hundred years later, and one hundred years before the American Revolution, Olaf Roemer conducted the first true measurement of light-speed in 1676.
He noted that the time elapsed between eclipses of Jupiter with its moons became shorter as the Earth moved closer to Jupiter, and became longer as the Earth and Jupiter drew farther apart. The explanation was simple: light has a definite speed. He calculated that the speed of light was something like 2.14 x 108 meters per second.
This measurement, considering that in the 17th Century Mr. Roemer didn’t have any computers or calculators, is surprisingly close to the modern value of 2.99792458 x 108 meters per second. This modern value, very precise, was obtained using powerful and accurate measuring devices. If you want the fancy name, here it is: “Laser Interferometer.” You don’t have to remember it.
In our modern age of science and technology, we now know for an absolute fact that when we look at objects that are far, far away – stars and other planets, for example-- the light that is hitting us now actually started from the object quite a long time ago.
Light from the Sun takes about 8 minutes to reach us here on Earth, so when you look up at the Sun you see it as it was 8 minutes ago. Alpha Centaurus, which is the closest star to us, is about 3 light years away. This means that the light we see from it now left the star about 3 years ago.
The farther away the object, the farther back in time we are seeing. The invention of the telescope, followed by ways of making telescopes more and more powerful, enabled us to learn about the our galaxy – the Milky Way – and our Solar System.
Q: What is the Milky Way?
A: Besides being the American name for the chocolate candy that people in other countries know by the name, Mars Bar, the Milky Way is the large spiral galaxy in which we live.
The Milky Way has at least 100-300 billion stars, and it takes light 100,000 years to cross from one side of the Milky Way to the other. We used to think that the Milky Way was the entire universe. Today, we know better.
The Solar System is located in a quiet neighborhood in the Milky Way, about half way out from the center. The Milky Way is one of the billions
of galaxies in our universe. The Milky Way is not standing still in space. It is rotating at 200km per second. One complete rotation takes more than 200 million years.
If you want to know the diameter of the Milky Way, you should put 12 more zeros on the number 946080, and you will have the diameter in km. Our brains cannot comprehend such a vast distance because it is so outside the realm of experience and reference.
From these billions of galaxies in our universe the closest one to the Milky Way has a distance of millions of light years. Hence, living in the Milky Way is similar to living on a farm in Saskatchewan. You have neighbors, but it takes a while to visit them.
In the giant scheme of things – and I do believe there is a scheme – our galaxy is tiny, and the planet upon which we live is smaller still. We people, in comparison to the vastness of space, are mere atoms. Atoms, however, are very important.
The Solar System
Solar means “Sun.” It could be called the Sun System, but Solar sounds more fancy and official. The Solar System is made up of all the planets that orbit our Sun. Also in the Solar System are moons, comets, dust, asteroids, gas, and all those satellites and space stations that have been launched from Earth.
The Sun
The Sun is a star made of hot gases, containing many of the same materials we find here on the Earth. These elements include hydrogen, helium, calcium, sodium, magnesium, and iron.
The light of the Sun results from the change of hydrogen to helium, and we see that light as bright yellow. Sunlight actually contains all the colors. When sunlight shines through a raindrop, the light divides into the various hues of the rainbow. You can bounce sunlight off a CD and you will see the rainbow pattern on the wall.
The Sun has three layers, and the inner core is 3,000 times hotter than the surface, and the surface is fifty times hotter than boiling water. As the gases on the Sun burn, giant fire storms are created. One flame from these storms is larger than 23 Earths. In addition to light and heat, the Sun also provides nourishment.
Plants use sunlight to turn carbon dioxide and water into food and oxygen. The more plants we have, the more oxygen is created.
The Sun contains around 98% of all the material in the Solar System. It is hot and huge. It looks about the same size as the Moon, but that is because it is 93 million miles away.
If the Sun were the size of a basketball, Earth would be about the size of the head of a pin. It would take more than 100 Earths to span the Sun’s width. If the Sun were hollow, you could fit a million Earths inside it.
Gravity
When it comes to gravity, size matters. The bigger the object, the stronger the gravity. Gravity is an attraction that exists between all objects, everywhere.
If you have ever had anything fall on your head, your foot or the floor, you have seen the Law of Gravity in action. As famed commentator Allen Daniel Goldblatt once said, “Gravity isn’t just a good idea; it’s the law..” Gravity is constantly causing adhesion and cohesion, and it plays a strong role in our day to day live on Earth.
Without gravity we wouldn’t walk, or even have a decent sense of balance. The nerves inside our muscles relay information about our bodies, and it relationship to its surroundings. When we take a step on solid ground, we push ourselves up and forward with our foot. Were it not for gravity, we would only go up, and have no sense of judgment as to where we are relative to other objects. Our bones, muscles, nerves and all the interrelated senses operate within a framework of learned response to Earth’s gravity.
Sir Isaac Newton (1642 -- 1727) was the first person to write a Theory of Gravity. Gravity existed long before he came up with what he called the Law of Gravity. Gravity was a fact; Newton’s Law of Gravity was a theory. A theory explains how the “fact” works. A theory can be tested over and over, and you can get predicted outcomes.
Newton figured out that some force (gravity) changes the speed or direction of something thrown in the air, or dropped from a building. Apples fall from trees, said Newton, because gravity pulls or pushes all things towards the center of the Earth.
According to Newton, the sun has a gravitational pull of its own that draws Earth closer to it. At the same time, however, Earth is spinning sideways away from the sun at just the right speed to keep us where we are – in orbit around the sun.
We are being pulled in two directions at once, and turning and spinning all at the same time, and we never really notice. As we go about our daily lives, it seems as if the Earth is standing still, and the sun appears to rise, travel across the sky, and go down at night. In truth, the sun doesn’t rise, travel or set. The sun doesn’t move; we do.
If the balance between the sun’s gravity and Earth’s gravity were not perfect, we would have been sucked into the sun and fried to a cinder long ago. That is true for the other planets as well.
There are, however, two primary problems with Newton’s theory. First of all, his calculations were not completely accurate. The second problem is why Newton believed gravity occurred. He believed that gravity, as we mentioned, was a force or power within all things.
In day to day operational reality, it doesn't matter why gravity works, it only matters how it works. When we began exploring certain large structures in outer space, and sub-microscopic structures as well, Newton’s theory didn’t always work. This is where Albert Einstein came in.
Albert Einstein, the most famous scientist of the 20th Century, came up with his own theory which states that there is no force of gravity. Gravity, said Einstein, is nothing more than space itself being "bent" by the massive objects in it. When one object falls toward a more massive object it is not being pulled or pushed by gravitational force. Instead, it is really just "rolling down hill" on the curve created by the more massive object. Einstein’s Theory of Gravity has been proven correct by several incontrovertible experiments.
The proof that Einstein was correct has not displaced Newton in terms of the most common calculations of gravity because Newton’s theory “works” in most situations because it is mathematically easier. As we said, Newton’s why was not correct, but the how is close enough for, shall we say, day to day use in the most common applications.
Now, here is an interesting twist to the story. There are places in the quantum world, very small spaces, where Einstein's rules don't apply. In attempts to explain why, scientists are developing new theories of quantum gravity. As more than once scientist has found, Newton’s theory seems to work in instances where Einstein’s doesn’t and Einstein’s works where Newton’s doesn’t. Once again we discover that nothing is simple. There is always more to learn, more to discover. No matter how much weight we give to a scientific theory, there is always the possibly of further enlightenment.
Weightless in Outer Space
In outer space, where there is no gravity, an astronaut’s muscles will atrophy. Muscle tone will decrease by five percent per week in a gravity free environment. Obviously, we can’t live naturally in a gravity free environment because our sinews will turn to mush unless we have some sort of gravity replication. For each day in space, an astronaut requires a day of physical therapy to regain muscle tone.
There are other challenges inherent in a weightless environment. When Astronauts want to sleep, they must tie themselves down, and the beds must be on the ceiling. If they didn’t do this, our Astronauts would not toss and turn in their sleep, they would float and bump.
Eating and swallowing are also subject to gravitational influence. Hence, food must be firmly tossed into the mouth lest it slip away. It doesn’t take much imagination to grasp why Astronauts cannot use a traditional toilet to relieve themselves. Their suits are especially designed to deal with those issues
Gravity is considered on of the four major forces that rule the universe. The other forces are electromagnetic force., weak nuclear force, and strong nuclear force. Yes, many people add a fifth power, but there is disagreement on what exactly to call number five. Some scientists term it “The underlying forces.” Yes, plural. Others call it “The Controlling Power,” and more recently “Dark Energy.” I don’t want to get ahead of myself here, so suffice it to say that whether there are four, five or six major forces, they are all very interesting because they have a remarkable influence over your life even if you have never heard of them. These forces effect everything in the Solar System.
Look, up in the sky!
People have wondered about the Solar System ever since someone saw a star in the sky. Over time, we learned that there were other planets orbiting our sun, and we gave those planets names.
The four planets closest to the sun are Mercury, Venus, Earth and Mars. All of these are solid planets. You can land on them. Don’t try that with Jupiter, Saturn, Uranus, Neptune and/or little Pluto. They are all giant balls of gas, except Pluto which is not really a planet, but a chunk of ice and rock.
The Planets
I'm sure you know about the planets in our Solar System, but just for fun, allow me to refresh your memory.
Mercury
You don’t want to live on Mercury, the planet closest to the sun. It is 36 million miles from the sun, but that is too close for comfort. Even if you wanted to live on Mercury, you can't because it is too hot. It looks a lot like the Moon, and it isn’t much bigger. It has craters, a wrinkly surface, 88 days of sunlight, and 88 days of darkness. Half the year is sunny; half the year is dark.
On the sunny days, Mercury reaches 800ºF. On the dark days, the temperature drops to –290º F. The Hubble Space Telescope can’t take pictures of Mercury because it is too close to the Sun. It would be a shame to melt such an expensive piece of equipment.
We did send a space probe to Mercury, but the first detailed study of the planet won’t be until 2011 when Mercury Messenger will enter Mercury’s orbit. We do know that the diameter of Mercury is 3032 miles, but not because anyone paced it off. It only takes Mercury sixty days to orbit around the sun compared to Earth’s three hundred sixty five days. If you go outside and look for Mercury in the night sky, you will have trouble seeing it.
Venus
Venus is 67 million miles/108 million km from the sun, and is the most visited planet in the Solar System. Over twenty space probes have poked around what was once called Earth’s Sister Planet. The Venus Express reached Venus in 2006, using sunlight as its power source.
The reason Venus was called our Sister Planet is because it is about the same size as Earth, so the gravity is much the same. That’s where the similarity ends. Venus is no vacation paradise because of the heat and atmosphere.
The entire planet is shrouded in a deadly cloud of sulfuric acid, and the atmosphere is 96% carbon dioxide. It also spins counter-clockwise on its axis, and a day on Venus is longer than a year on Venus. This is because a day is the amount of time it takes for a planet to revolve, and a year is the amount of time it takes for a planet to orbit the sun.
It takes 224 days for Venus to orbit the sun compared to 365 for Earth, and Venus revolves every 243 days. On Earth, it takes us 24 hours. Venus is even hotter than Mercury, despite Mercury being closer to the sun. The temperature on Venus is about 900 F compared to Earth’s 59 F (15 C). There are, however, some potentially interesting tourist attractions: giant volcanoes, deep valleys, and dreadful Venus-quakes.
We can see Venus clearly in our night sky. Nice to look at; unfriendly to life. The light of the sun arrives on Venus two minutes sooner than it does on Earth. This two minute difference allows the heat from the sun to cool down perfectly for life on Earth. Something as simple as a two- minute delay is the matter between a planet filled with life, and a planet that isn’t.
Mars
What makes Mars exciting is that it once had rivers, streams, lakes and even an ocean or two. Perhaps that means that there was once life on Mars. Perhaps not. We will discuss that in a minute.
Mars has higher mountains, and deeper canyons than any other planet. The largest canyon on Mars would stretch from New York City to Los Angeles on the Earth. That makes the Grand Canyon look tiny. It also has the Solar System’s biggest volcano, Olympus Mons.
Earth is between Venus and Mars. There is life on Earth, and you are part of it. Planets similar to Earth, with all the conditions for evolving the same or similar forms of life as we have on Earth, may or may not exist. The conditions for life as we know it are exceptionally complex and amazingly precise.
Whether or not similar life exists elsewhere depends on several factors. (1) How typical is the galaxy in which humans live? (2) How typical is the Solar System? (3) How typical is the Earth. The answer, in the opinion of some scientists is, “not very typical.”
It is possible that Earth is the only planet in the universe that has remained stable long enough for complex life as we know it to develop.
There is the concept that life doesn’t necessarily depend on conditions being anything such as we have on Earth. In other words, life forms exist potentially, and become manifest in accordance with the conditions of the planet.
On Earth, plants and animals require certain things to thrive. It is possible that on other planets there are life forms that have entirely different requirements. We won’t know if that is true or not until we encounter life forms on or from other planets.
The gravity on Mars is one third of the gravity on Earth. The diameter of Mars is 4222 miles compared to Earth’s 7926 miles.
Mars is 141 million miles from the sun. Days and nights on Mars are similar to Earth’s, but it takes two years of our time for Mars to orbit the sun. The temperature on Mars is always too cold even for earmuffs. In winter, it is -191 F (-125 C). In the summer, Mars is a balmy -81 F (-63 C).
Jupiter
Jupiter is the largest planet in the Solar System. Its diameter is 88,846 miles. In fact, it is bigger than all the other planets put together, and you could fit over thirteen hundred Earths inside it. Despite its size, the only solid part of Jupiter is a rocky core. The rest of the planet is simply a huge ball of gas surrounded by clouds. Most of this gas is comprised of helium and hydrogen.
If you're looking for moons, Jupiter has plenty of them. Sixty three moons circle Jupiter, and some of them are quite lively. By that I mean they have active volcanoes that spew sulfur. This makes the volcanic moons appear yellow.
Storm chasers would love Jupiter. It has a storm called the Great Red Spot that is three times the size of Earth, and the wind whips at 400 mph.
The planet also has impressive lightning storms. Not the universe's most inviting weather profile, but a subject of much fascination for further study and research. This planet appears as if it has multi layers, but what we are actually seeing is cross currents caused by the violent winds.
Jupiter itself has much in common with the Sun. It is possible that Jupiter was a potential star that never got big enough to start burning like the sun. Now would not be a good time for it to start. It takes twelve years for Jupiter to orbit the sun, and only one hour for it to revolve on its axis. The average temperature is from -110 C to -222 C.
The sixth planet from the Sun, Saturn is also a giant gas ball. Nine times larger than Earth, it is famed for its rings which are made of millions of pieces of rock and ice. Some of the pieces are tiny; others are the size of a luxury sedan. Rings are not unique to Saturn -- all the gas planets have them -- but Saturn's are visually spectacular because they reflect sunlight. The diameter of the rings is 170,000 miles, and they are 150 feet thick (46 meters). Saturn also has sixty moons, but the rings get all the publicity.
Saturn is 886 million miles from the sun. It takes thirty years for Saturn to orbit the sun, and eleven hours to rotate on its axis. The planet’s diameter is 74,898 miles. Yes, it is big and cold.
Uranus
Uranus is a very unusual planet. It sits on its side with the north and south poles sticking out the sides. It rotates around this axis once every seventeen hours, and looks like a ball rolling around in a circle around the Sun.
Uranus is 1.8 billion million miles from the sun, and it takes eighty four years for Uranus to complete its solar orbit. The diameter of Uranus is 31,764 miles.
William Hershel, who invented his own telescope, discovered Uranus on March 13th, 1781. He named the planet George's Star in honor of King George III. While patriotic, astronomers preferred a name more in keeping with tradition. The name was changed to Uranus, after the Greek god of the sky. King George III was unavailable for comment.
Even with its diameter of 31, 764 miles, and the use of telescopes, it is difficult to learn details about the planet. In 1986, the space probe Voyager 2 was able to send back detailed images of Uranus. The Hubble Telescope was used to observe Uranus in the 1990's, revealing a blue-green disk with a cloudy atmosphere where six hundred and fifty mile an hour winds blow around the planet.
Uranus may have up to twenty-one moons, but this is not yet definite. Being a gas planet, Uranus has a system of eleven rings made of rock and dust that may be the result of meteors colliding with one or more of the planet's moons. Uranus is a difficult planet to study because (a) it is very far away, and (b) sending a space probe is expensive. Uranus is made of ice, gases and liquid metal.
Unlike Jupiter and Saturn, where the atmosphere is made of the simple molecules of hydrogen and helium, the atmosphere of Uranus is cold enough to contain more of a complex molecule called methane along with a generous helping of ice. Methane stinks, and it is what gives Uranus its blue coloration.
Neptune
Neptune, an "ice giant,” is the eighth planet from the sun in our solar system, and it is exceptionally large, horribly cold and has the distinction of being the most windy planet in the Solar System. Winds whip up to over 1,000 miles per hour, and the storms on Neptune are the size of Earth. It as discovered in 1846, and its diameter 30776 miles. It is 2.8 billion miles from the sun which it orbits once every 165 years.
Neptune looks blue because the methane in its atmosphere absorbs red light. It has thirteen moons; one of them is Triton, the coldest known object in the Solar System. It has attractive and stylish pink ice caps.
Triton also has active volcanoes that shoot dust gas and water into the air where it all freezes and falls back on Triton like snow.
Neptune is the final full-size planet in our Solar System. There are other planets, but they are termed Dwarf Planets because they don't meet the new minimum size requirement to be considered planets.
Pluto
Pluto, discovered in 1930, and named by an eleven year old girl from Oxford, used to be the ninth planet in our Solar System. Because it is smaller than our Moon, it was recently re-categorized by scientists as a Dwarf Planet. Pluto is not the only Dwarf Planet in our Solar System. Eris is three times further away from the Sun than Pluto.
Another Dwarf Planet is Ceres, located between Mars and Jupiter. A Spacecraft called Dawn is on its way to learn more about Ceres, but won't reach that little Dwarf Planet until 2015. If you are eager for more information, you will just have to be patient.
Learning isn’t Knowing
Just because we learned that there were other planets, didn’t mean we knew anything about them, or how our Solar System worked. For the longest time, people believed that the Earth was the center of the universe, and everything revolved around it. The Earth itself, they believed, did not move.
In the 1st Century AD, the writings of Ptolemy detailed the elaborate system of wheels that kept the universe moving around the Earth. The early Christian Church eagerly embraced the erroneous theory of an Earth centered universe because it put God’s greatest creation, man, at the center of everything. This concept ruled the minds of Europe for 1600 years.
When Copernicus (1473-1543) distributed a hand written pamphlet among his friends in which he asserted that it was the sun, not the Earth that was the center of our system, he had good reason to not publish and promote it amongst the general public. His theory contradicted the Church’s position, and he was himself a member of the clergy. Exercising prudence, Copernicus personally reviewed the proof pages, but arranged post-mortem publication. The book was in Latin, the language of science; the author, being deceased, couldn’t be punished. The Church chose to ignore the issue altogether.
Galileo, born about twenty years after the death of Copernicus, had the good fortune of being mentally gifted, exceptionally brilliant and amazingly inventive. Four years after completing his basic education, he was a university professor of mathematics. Some people think Galileo invented the telescope. He didn’t. He bought some lenses, built his own telescope, and made amazing observations.
Among his observations were first-time descriptions of the four moons of Jupiter, the rotation of the Sun on an axis, the existence of Sun spots, the rough complexion of the Moon, including craters, and the spiral nature of the Milky Way. When he published his findings in 1610, he became an instant celebrity.
His good fortune was offset by the misfortune engendered by his publication, in 1613, of an exceptionally clever book presenting persuasive arguments favoring the Copernicus model of a Solar System rather than an Earth System. The Earth, he proclaimed, moved in rotation around the Sun.
Unlike Copernicus’ widely ignored tome, Galileo’s fame as a brilliant astronomer and inventor assured a wide and receptive audience. Neither his celebrity status nor cordial relations with the Pope protected Galileo from the Church’s outrage. Summoned to an Inquisition, Galileo defended his accurate portrayal four times. Threatened with torture and/or being burned at the stake, Galileo decided death was not his preferred option, and recanted his position. This brilliant man, whose contributions to science are innumerable, spent the remainder of his life under house arrest, his visitors confined to immediate family.
While the validity of the Copernicus model, advanced by Galileo, was declared false by the Church, obstructing its promulgation did not make it less true. Suppression increased curiosity, and the forbidden fruit of accurate information became increasingly appealing.
Human beings strive to know, understand, question and search. And as there is always more to learn, we have to be willing to revise what we believe. Even our most modern concepts, built on a firm foundation of facts coupled with scholarly speculation, are subject to revision. If we learn something new, we should rejoice in our increased knowledge, and the increased questions such knowledge creates.
Increasing the power of our senses by technical means brings us new insights. Every time we make a more powerful telescope, our vision perceives something new and challenging.
Back in the 1920s, there was a powerful new telescope installed at the Mt. Wilson observatory in the hills above Los Angeles, California. A man by the name of Edwin Hubble took a look through that telescope. What he saw took his breath away, and blew away all previous ideas about our Solar System and the galaxy of stars and planets in which we live.
The Astonished Mr. Hubble
Edwin Hubble was an astronomer, but he certainly didn’t fit any stereotype you might have in your mind. American born, educated in the UK, his colorful life included dynamic performances in the boxing ring, scars from a dueling match, and a law degree.
Blessed with a brilliant mind, Edwin Hubble decided to become an astronomer. He succeeded, becoming the most famous astronomer of his lifetime. The Hubble Space Telescope, obviously, was named after him.
The Hubble Space Telescope
It is a bit out of time sequence to talk about the Hubble Space Telescope in this particular space in the book, but doing so demonstrates the fluidity of time and space. “Not since Galileo turned his telescope toward the heavens in 1610,” wrote NASA, “has any event so changed our understanding of the universe as the deployment of the Hubble Space Telescope.”
Launched in 1990, the Hubble Space Telescope was first of a series of four space orbiting satellites that carry telescopes designed for observing in visible light, but also have infrared cameras and spectrometers for “seeing in the dark.”
True to its educational nature, the Hubble Space Telescope is about the size of a large school bus. Even with that length and bulk, it fits easily inside a space shuttle’s cargo bay.
The Speed of Hubble
The Hubble Telescope is zipping along at about 18,000 miles per hour, and can orbit Earth in 97 minutes. That is faster than a speeding bullet, which can hit speeds of 5000 feet /1500 meters per second for some large guns. If you could travel at the Speed of Hubble, you could make it from New York to Los Angeles in 10-15 minutes, depending upon traffic.
The Hubble’s operations are controlled by scientists in Baltimore, Maryland. As with any piece of machinery, it requires frequent tune ups and repairs. It received minor tweaks in 1993, 1997, 1999, 2002, and on- site repair by the seven member crew of Space Shuttle Atlantis while the space telescope was orbiting 350 miles above Earth.
Space Shuttles such as the Atlantis were retired in 2010 and replaced by Crew Exploration Vehicles which fulfill the same duties plus additional shuttle servicing missions. As for the Hubble Space Telescope, it is being partially replaced by the new James Webb Space Telescope (JWST). This is a large, infrared-optimized space telescope, scheduled for launch in 2014, that will find the first galaxies that formed in the early Universe, connecting the Big Bang to our own Milky Way Galaxy.
“JWST will peer through dusty clouds to see stars forming planetary systems, connecting the Milky Way to our own Solar System,” says NASA. “JWST's instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. JWST will have a large mirror, 6.5 meters (21.3 feet) in diameter and a sunshield the size of a tennis court.”
Something that big won’t fit onto a rocket, so the mirror and sunshade will be folded up before launch, and unfolded once they are in outer space at about 1.5 million km (1 million miles) from the Earth.
Holding Webb Steady in Space
Scientists want the Webb Telescope to “hold still” in space, and this is accomplished by placing it at specific point where it balances perfectly between the gravity of the sun, and the gravity of the Earth. The place of perfect balance is called “The Second Lagrange Point,” or “L2,” and named after the Italian-French mathematician Joseph Louis Lagrange who came up with this idea in 1772.
As NASA said, the Hubble Space Telescope changed our understanding of the universe. It was Mr. Hubble personally looking through a telescope at Mount Wilson, California, back in the early 1920’s that altered forever how human beings see themselves in relation to the universe.
Edwin Hubble, the pipe smoking astronomer, has the remarkable distinction of being the first person to actually see, thanks to what was then the most powerful telescope on Earth, that the universe was vast beyond comprehension, and that the galaxies were moving. In fact, the farther away they were, the faster they moved.
“No person in history,” stated NASA, “has had greater impact in determining the extent of our universe than Edwin Hubble. From proving that other galaxies existed to proving that galaxies move apart from one another, Hubble's work defined our place in the cosmos.”
The full implication of this discovery didn’t occur to Hubble and his co-worker, Vesto Slipher, immediately. It was startling enough to see and confirm that the universe was dynamically expanding, and that it was the space between galaxies that was continually increasing.
Before Edwin Hubble’s discoveries, we thought that our galaxy, the Milky Way, was all there was to the universe. Even Albert Einstein thought that the universe was, well, just sitting there. No one ever imagined that the universe was a moving, living, breathing, growing, and evolving “creation in process.” Surprise.
It took twenty years before the obvious was put on the table for discussion: If the future is one of more space between galaxies, then the past must have been one of less space between galaxies.
Sounds simple enough, doesn’t it? In fact, it seems obvious. If there is more today than yesterday, then there was less yesterday than today. If there is more, there must have been less.
There is more space every day. There must have been a day of no space at all. It was compressed. Suddenly, it uncompressed.
Bang – instant expanding universe.
In simple terms, for those of you who use computers, one might think of the universe as a Zip file that is being extracted. It is a compressed file that is opening up, decompressing, and getting larger and larger as it does so. There are now many wonderful detailed scientific books explaining step by step, exactly what happened at that “moment,” and in what order. What we will do in my desire to keep this amazingly simple is, well, keep it amazingly simple
Billions of anything is a lot of something. A billion seconds is about 32 years. A billion minutes is 1901 years. A billion hours is a bit over 114,000 years. A billion years is, well, a long long time. The universe decompressed 13.7 billion years ago. That isn’t a wild guess. In fact, it is very precise.
Q: How can that be precise?
A: Because we know the speed of light. We can measure distances and the time it takes to get there. Plus, we can count backwards.
Remember Albert Einstein? He is the famous scientist who came up with the revolutionary theory of gravity. He is also famous for E=MC2. That is his equation for his Theory of Relativity. It is very complicated and hard to grasp because it is difficult to explain in words because it is a mathematical equation. Statements that do not contradict each other in math are often contradictory when you write them in English.
What E=MC2 basically says is that matter and energy are two forms of the same thing and that you convert between the two by either multiplying or dividing by the speed of light squared. I’m about to do you an enormous favor. You can thank me later. I’m going to give the bottom line in five words.: "Nothing is faster than light."
You could also say, "light travels faster than anything, and you can’t travel faster than light, so don’t bother trying because it won’t work." That, however, is a long sentence. Einstein wasn’t into writing sentences as much as he was into writing mathematical equations. The speed of light is constant.
If we have powerful enough telescopes, we can “look back in time” to some sort of beginning – if there is/was a beginning. After all, if something exists, it exists. If it doesn’t exist, it doesn’t. The universe
exists. That could mean that it always existed, if only potentially, much as the tree exists potentially in the acorn.
You can chop an acorn into a billion pieces, and never find a tree. If you plant and nourish that acorn, a mighty tree will grow.
The Big Bang and Beyond
According to the standard Big Bang model, the universe was born during a period of inflation that began about 13.7 billion years ago. Like a rapidly expanding balloon, it swelled from a size smaller than a dot to nearly its current size within a tiny fraction of a second.
At first, the universe was permeated only by energy. Some of this energy congealed into particles, which assembled into light atoms like hydrogen and helium. These atoms clumped first into galaxies, then stars, inside whose fiery furnaces all the other elements were forged.
This is the generally agreed-upon picture, explaining much of what we see when we look in the sky, such as the remarkable smoothness of space-time on large scales and the even distribution of galaxies on opposite sides of the universe.
But it may be wrong. Not 100% wrong, but we are learning more every day. Scientists understand that when we learn, old ideas give way to new information. For starters, the idea that the universe underwent a period of rapid inflation can’t be tested, and it relies upon the existence of a mysterious form of energy called “Dark Energy.”
Q: What is Dark Energy?
A: Dark Energy is considered the “missing ingredient” in the expansion of the universe following the Big Bang. Scientist figured that some force existed that causing the expansion of space – some type of anti-gravity force. They didn’t know what that force was, or how it worked. Dark Energy is considered the “fifth power” by many scientists.
In 1998, this force was given the name, Dark Energy, by Michael Turner. It began as a theory based on some very sound observations. Over time, and with extensive research, evidence of Dark Energy was firmly established by the use of super-powerful telescopes studying distant supernova stars. This 2005 study was called the Supernova Legacy Survey. The Hubble Space Telescope has given scientists the most compelling evidence indicating that Dark Energy has been present in the universe for over 9 billion years.
There is also a something called Dark Matter, which is envisioned as a sort of inter-galactic syrup that holds things together when gravity doesn't seem an adequate explanation. Recently, it has been suggested that Dark Energy and Dark Matter are really two aspects of what is termed Dark Fluid.
The idea is this: Dark Fluid acts differently in different situations and conditions. It can propel expansion, and it can hold things together.
These different theories are not wild guesses. They are all based on solid information, of which we get more all the time.
The question isn't "Was there a Big Bang?" The question is about the ingredients and the process. There is so much evidence -- both sight and sound -- that there is no doubt that the Big Bang happened.
Seeing the Sound of the Big Bang
Sound waves, even remnants of sounds from eons ago, can be analyzed and studied. In 2005, astronomers saw in the patterns of galaxies scattered across the night sky, the vestiges of sound waves that rumbled through the universe after the Big Bang. Stars and galaxies tended to form along the ripples of the sound waves where matter was slightly denser, and the pull of gravity was slightly stronger.
The ripples preserve a picture of the universe when it was only about one million years old and fit well with astronomers' ideas of how the universe, which started smooth and uniform, became lumpy with stars, gas clouds and other celestial objects.
Another important critical discovery was the observation of low levels of microwaves throughout space. Obviously, microwaves are not simply used for cooking quick meals. Astronomers believe these microwaves, whose temperature is about -270 degrees Celsius, are the remnants of the extremely high-temperature radiation produced by the Big Bang.
We can get an idea of how hot the universe used to be by looking at very distant clouds of gas through high-power telescopes. Because light from these clouds can take billions of years to reach our telescopes, we see such bodies as they appeared eons ago. These old clouds are hotter than the younger ones.
Scientists have also been able to uphold the Big Bang theory by measuring the relative amounts of different elements in the universe. They've found that the universe contains about 74 percent hydrogen and 26 percent helium by mass, the two lightest elements. All the other heavier elements -- including elements common on earth, such as carbon and oxygen -- make up just a tiny trace of all matter. This could only happen, experts assert, in a universe that began in a very hot, dense state, and then quickly cooled and expanded.
Here is the basic idea: in the first few minutes after the Big Bang, the universe was far hotter -- billions of billions of billions of degrees hotter than anywhere in the universe today. This heat gave particles of matter in the early universe an extraordinary amount of energy, causing them to behave in a much different way from particles in the universe today. For example, particles moved much faster back then and collided into one another with much greater energy.
Q: If these conditions do not exist anymore, how do scientists study the behavior of matter in the early universe?
A: One of the most powerful tools for such analysis is the particle accelerator. This device allows physicists to recreate conditions just after the Big Bang by making a beam of fast-moving particles and bringing them together in very high-energy collisions.
As with all scientific models, the Big Bang undergoes continual revision as our knowledge increases. The real problem arises when the pieces of knowledge don’t fit together into a coherent theory. That’s when scientists began worrying that they are engineering a model instead of explaining one.
There are several different concepts of how the universe expands, how long it will continue to do so, and what will happen when it stops expanding.
A Beginning that Isn’t a Beginning.
Perhaps the universe didn’t begin with the Big Bang, but began again. It could very well be that the universe is ageless. In this theory, the universe was born not just once, but multiple times in endless cycles of fiery death and rebirth.
Two contemporary physicists, Paul Steinhardt of Princeton University and Neil Turok of Cambridge University) suggest scientific validation of the ancient religious ancient concept that space and time have always existed. They use developments in String Theory to support the belief that there is “no beginning and no end.”
String Theory
Sometimes referred to as "a theory from the 21st century physics that was accidentally discovered in the 20th century," string theories define the basic building blocks of the universe as little filaments of energy that vibrate in mufti-dimensional space-time. Steinhardt and Turok suggest the Big Bang of our universe is as a bridge to a pre-existing universe, and speculate that universes are created over and over again, each one evolving over trillions of years.
This is a new idea for science. This is not a new idea, however, for some of the ancient religions. The unscientific belief that the world is approximately six thousand years old is actually a fairly recent rejection of the eternal nature of “creation”
The Bhagavad Gita clearly says, "Material nature and the living entities should be understood to be without beginning. Their transformations and the modes of matter are products of material nature."
This theory of cycles and transformation would explain not only inflation, but other cosmic mysteries as well, including dark matter, dark energy and why the universe appears to be expanding at an ever- accelerating pace.
While controversial, this concept supports the oft stated view of numerous philosophers and religious figures that the universe is ageless and self-renewing. As one well known philosopher of the early 1900’s said:
It is certain that this world of existence, this endless universe, has neither beginning nor end. Yes, it may be that one of the parts of the universe, one of the globes, for example, may come into existence, or may be disintegrated, but the other endless globes are still existing; the universe would not be disordered nor destroyed; on the contrary, existence is eternal and perpetual. - Sir Abbas Effendi Abdul'-Baha
The above quote utilizes a sound scientific principle: if something doesn't exist, it doesn't exist. If it exists, it has always existed, even if only potentially. All this points to one indisputable fact: the universe is on purpose. Form follows function. The very fact that it has form implies function -- purpose, reason and intention. A "purpose" by its very nature has an agent, some sentient entity capable of intent.
Earth did not suddenly appear looking exactly as it does today any more than New York City suddenly appeared looking as it does today. Our little planet passed through different phases and stages, and continues to do so.
There is another important proof that life and the universe are not accidental: There is uniformity of system from the smallest (microcosm)to the largest (macrocosm). The smallest atoms in the universal system are similar to the greatest beings of the universe. It is clear that they come into existence from one "laboratory," one natural system, and one universal law.
The most obvious proof that life is not accidental is that all life forms reproduce. Flowers, trees, fruits, vegetables, and all living creatures reproduce. No being can come into existence from an accidental composition, let alone continue reproducing in a universal manner.
There's Something Happening Here
I recently heard a scientist on the radio state that "something" happened in 1844, but the nature of that "something" was unknown. Whatever it was, it ignited an incredible and ever increasing advancement of newness, novelty and discovery in all fields of science, technology, medicine, travel, art and everything else.
If you look at the great strides in the acquisition of human knowledge since 1844, you see that this fellow is correct. There has been more learned about life and the universe since 1844 than in all previous history.
Some folks go through life thinking these amazing discoveries don’t actually impact their daily lives. Nonsense. The fruits of these advancements are found all around you every day.
Do you have a GPS unit in your car? It’s one of those devices that give you directions. It tells you where you are, where you are going, and how long it is going to take you to get there. Even cell phones have them as an option, complete with a voice giving you turn by turn directions.
The technology of GPS is similar to the technology that tells us about the origin of the universe. GPS works because we know the speed of light.
`Global Positioning System satellites transmit signals to equipment on the ground. GPS receivers passively receive satellite signals; they do not transmit. GPS receivers require a clear view of the sky, so they are used only outdoors and they often do not perform well within forested areas or near tall buildings. GPS operations depend on a very accurate time reference, which is provided by atomic clocks at the U.S. Naval Observatory. Each GPS satellite has atomic clocks on board.
Each GPS satellite transmits data that indicates its location and the current time. All GPS satellites synchronize operations so that these repeating signals are transmitted at the same instant. The signals, moving at the speed of light, arrive at a GPS receiver at slightly different times because some satellites are farther away than others. The distance to the GPS satellites can be determined by estimating the amount of time it takes for their signals to reach the receiver. When the receiver estimates the distance to at least four GPS satellites, it can calculate its position in three dimensions.
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