When it comes to moons, it seems that Earth got cheated. We have only one moon while Mars has two. Neptune has fourteen moons. Uranus has twenty-seven. Saturn not only has rings, but it also has sixty-two moons. Lucky Jupiter has sixty-seven! To add to the embarrassment, puny little Pluto, which is no longer considered a planet, has five times as many moons as Earth has! The only bragging point we have is that we can say we have more moons than Mercury and Venus. (They have none.) So how many moons are enough?
Actually, one works very nicely. Our single moon is critical to the existence of life on Earth. It’s because of the moon that Earth has a stable tilt on its axis of 23.5 degrees. That tilt prevents temperature extremes on this planet. With no inclination, the area of the Equator would be extremely hot and the poles extremely cold and dark all year. With a greater tilt, seasonal weather changes would be extreme all over the planet. Because of the angle of the inclination, we have proper seasons, and the air gets mixed to temper the weather extremes.
Our moon has the right mass at the right distance to keep Earth’s tilt stable. The moon plays several crucial roles in making our planet a great place to live, but stabilizing the tilt is one that’s extremely important. So how many moons are enough? I would say that one moon of the right size and at the right distance is just right.
Genesis 1:14 says that God allowed the “lights in the expanse of the sky to separate the day from the night” and to serve as “signs to mark seasons and days and years.” We can call them the lights of the seasons.
Although light is essential for our existence, the Sun, Moon, and stars are intended to serve an additional purpose. In Genesis 1:1 God created the heavens and the Earth. “Heavens,” or “shamayim” in the original Hebrew, would include the Sun, Moon, and stars. Genesis 1:14 tells us that God lifted the cloud cover (described in Genesis 1:2 and Job 38:9) so that the heavenly lights could be clearly seen to establish the circadian rhythm, give us a way to determine directions, and allow us to mark the passage of time.
Today (December 21) is the time when the Sun reaches its lowest point in the sky. In the Northern Hemisphere, it is the shortest daylight and marks the first day of winter. In the Southern Hemisphere, it is the most extended daylight which marks the first day of summer. We call it the winter or summer solstice. The word “solstice” comes from two Latin words meaning “sun” and “stand still” because on this day the Sun appears to momentarily stop its southward journey and start back toward the north. (The opposite is true on June 21.)
When Earth has made one complete rotation on its axis, the Sun’s position shows us that one day of 24 hours has passed. When the Earth completes one revolution around the Sun (approximately 365 days), we can see that the Sun has finished one cycle of its apparent north-south swing. We know that one year has passed.
It’s the 23.4-degree tilt of Earth’s axis with respect to the Sun that causes us to have seasons as our planet makes its year-long solar revolution. That tilt makes it appear that the Sun is moving north and south through the sky each year and gives us seasons. Without seasons, only limited areas of Earth would be habitable. Without day and night, one half of the Earth would be baking in the sunshine while the other half would be continually cold and dark. When the Moon has made one revolution around Earth, we can see that it has completed all of its phases and we know that one lunar (or synodic) month has passed.
Most people know that the Moon causes tides. The gravitational pull of the Moon mostly causes the ocean tides. The tides are essential for cleaning the coastlines and estuaries.
On average, the Moon is 238,900 miles (384,470 km) from Earth. What if the Moon were only half of its present distance from Earth? The Moon half as far away from Earth would create ocean tides eight times higher than they are now. At one-fourth the current distance from Earth, the tides would be sixty-four times higher than they are today. Imagine a world with tides like that! Coastal cities around the world would be in danger. Coastal lowlands would be uninhabitable. The coasts would be eroded away in a short time. Upflowing tidal waters would overpower rivers that flow into the oceans. Floodplains along the rivers would fill and drain with each ebb and flow of the tide.
With a closer Moon, all kinds of aquatic creatures living along the shore would not survive the destructive forces of the tides. In addition to those catastrophes, seawater would deposit salt on the fertile land along the rivers making them barren. Glaciers along the coast of Alaska and Greenland and the Ross Ice Shelf in Antarctica would be broken up. Icebergs would clog the Atlantic Ocean. Icebergs would sometimes wash ashore with the tides in places far from the cold climates, crushing whatever was in the way.
Gravity controls the universe — at least on a large scale. Obviously, gravity keeps you and your possessions from floating away into space. Gravity also holds planets and stars together. It holds the Moon in orbit around the Earth and all of the planets in orbit around the Sun. Gravity holds the galaxies together. But other forces are stronger than gravity.
Four interactions make the universe work: the weak and strong nuclear forces, electromagnetism, and gravity. Gravity is by far the weakest of those forces. The weak and strong nuclear forces are limited to a very short range within the atom. Only the electromagnetic force and gravity reach out to the vast universe. Since the electromagnetic force is so much stronger than gravity, why does gravity control the universe?
Everything is made of atoms and atoms contain electrons and protons. Electrons have a negative charge, and protons have an equal and opposite positive charge. Electromagnetism causes opposite charges to attract and like charges to repel each other. Gravity, of course, pulls anything with mass together.
The reason electromagnetism does not overpower the much weaker force of gravity is a delicate balance between electrons and protons. For each electron in the universe, there is a proton, so the plus and minus electrical forces cancel each other, creating electrical neutrality. Without that balance, we could not exist.
The balance between electrons and protons is so delicate that if you were building a universe and accidentally put in one extra electron for each trillion trillion trillion electron/proton pairs (that’s one followed by 36 zeroes), it would be catastrophic. The electrical repulsion between those negatively-charged electrons would overpower the gravitational force. The result would be that gravity could not pull any mass together. If gravity could not pull masses together, there would be no planets, no stars, no galaxies. Electromagnetic repulsion would create a universe of dispersed particles and nothing else.
Our Moon is different from any other moon in our solar system. And as far as we know, it’s different from any other moon orbiting any other planet in our galaxy. The difference has to do with the Moon mass.
No other planet has a moon with a mass that is so large compared to the mass of the planet. While other planets have multiple moons, our single Moon is large enough in relation to our planet that it stabilizes Earth’s rotational tilt at 23.5 degrees in relation to our orbit around the Sun. No other planet in our solar system has such a stable rotation axis tilt. The stable axis allows us to have stable and reliable seasons.
Seasonal changes distribute the Sun’s energy over Earth’s surface allowing plants to grow and food to be produced over a large area. Without the seasons, much of the Earth would be too cold, and some areas would be too hot for advanced life. The Moon has enough mass at the right distance from Earth to make advanced life possible on this planet.
In fact, the Moon has almost too much mass. If the Moon had two percent more mass, it would destabilize the Earth’s tilt. Is there a reason for the Moon to be more massive that it needs to be to stabilize the tilt? Yes, there is. The mass of the Moon creates a pull on the Earth known as tidal friction. That force creates the ocean’s tides which refresh the coastlines.
There is another reason for the large Moon mass. It also slows the Earth’s rotation. In the early Earth, days were shorter. The Moon has put the brakes on our planet’s rotation slowing it to a 24-hour day. Slowing the rotation has affected Earth’s weather, reducing temperature extremes and distributing rainfall more evenly around the Earth.
Many times when a skeptic attacks a biblical story, the problem is caused by misunderstanding a word. In Joshua 10 there is an account of a battle between the Amorites and the Israelites. In verses 12 and 13 of the King James translation, Joshua said, “Sun stand still” and the Sun and Moon stood still for a whole day.
There is no question that God can make the Sun stand still. He can do anything He wants to do, but the physical consequences of stopping the Earth from rotating on its axis are enormous. The inertia of the water in the oceans, the effect on the atmosphere, and even the impact on the land masses challenge the imagination. A careful study of the words used in the biblical account resolves what appears to be an impossible statement in the scriptures.
The New Testament uses the Greek word “helios” which means Sun, but there is no Hebrew word for Sun in the Old Testament. In Genesis 1:16, the word for lights is “maor,” and the Sun is identified as “gadol maor” usually translated “greater light.” In Job 31:26, the Hebrew word is the shorter version “or” and Job 30:28 it is “chammah” referring to the heat of the Sun. In Judges 8:13 and 14:18 the word used is “cheres” again referring to the Sun’s burning heat.
In Joshua 10, the Hebrew word used is “shemesh” which refers to a ministrant, a device to minister to a need. It usually refers to the Sun but could be any ministrant. The word for Moon is “yareach” which refers to a wondering object. There is another interesting point about the words in the last part of Joshua 10:12. The pronouncement of God’s provision for the battle to continue says in the King James, “Sun stand thou still upon Gibeon (El-Jib today); and thou Moon in the valley of Ajalon.” Ajalon is in Dan and Gibeon is 4 miles from Bethel. These two locations are less than 30 miles apart. That fact should suggest that these are not the celestial Sun and Moon.
The question is not whether God caused a “great light” to allow the battle to continue at Joshua’s request, but what was the method by which God did it. There are many ways God could provide a great light or series of lights as a ministrant. Verse 11 speaks of “great stones from heaven” cast down on Azekah which was a town in Judah near Gibeon. Many astronomical possibilities to provide light are worth considering such as an asteroid or meteor shower or an aurora.
In 1957 when I was 19 years old and a junior at Indiana University, the Soviet Union placed Sputnik, the first artificial satellite into orbit around the Earth. The following year the United States established the National Aeronautics and Space Administration with the goal of staking America’s claim to the cosmos. NASA turns 60 this year with an incredible record of accomplishment.
There have been 166 manned missions, 116 satellites which study the Earth, 70 missions to the moon and planets, 27 telescopes/observatories placed in space, and 17 satellites studying solar wind and interplanetary science. We now have robots making incredible discoveries at every turn, and plans are in the works for the first humans to land on another planet.
As a physics major and later as a physics teacher I have been enthralled with NASA’s accomplishments. I have had students who graduated from my high school and went on to have key roles in NASA. As those students come back and share their experiences and what they have discovered, I have been encouraged. I am excited by the fact that most of them see their discoveries, as I do, as a way of learning what God has done and understanding some of the methods He has used.
Yesterday we mentioned an article by John Gribbin in Scientific American (September 2018, page 96 or online HERE.) The title of the article was “Are Humans Alone in the Milky Way?” Although Gribbin suggests that some form of life exists elsewhere in the galaxy, he insists there could be no sentient beings like ourselves. The reasons for concluding that we are alone in the Milky Way galaxy are these “amazing” and “implausible” “coincidences.”
SPECIAL TIMING. The elements that make up a terrestrial planet like Earth are produced from hydrogen and helium by thermonuclear fusion. We see supernova explosions producing the heavy metals that make up a terrestrial planet and life itself, but it takes time for this process to create the necessary elements. Most of the exoplanets we see have minimal amounts of the heavy elements because they are early in their stellar evolution. Even the sun itself is 71% hydrogen and 27% helium with only 2% metals. The timing of putting the materials together to make a terrestrial planet is critical.
LOCATION IN THE GALAXY. The location of a solar system in the galaxy makes a difference. The galactic habitable zone is the area where there is a freedom from the concentration of supernovae. Systems near the center of the galaxy have high levels of radiation in the form of X-rays and cosmic rays. There is a massive black hole in the center of our galaxy called Sagittarius A which produces massive amounts of radiation. Gamma-ray bursts occur in certain places in the galaxy. In our area of the galaxy, sterilizing radiation bursts do not happen.
Recent studies of the galactic habitable zone tell us that it extends from 23,000 to 30,000 light-years from the center or only about 7% of the galactic radius. This zone contains only about 5% of the stars, because stars tend to concentrate toward the core of the galaxy. Our Sun is close to the center of the galactic habitable zone providing rare long-term stability.
TYPE OF PLANET. So far astronomers have discovered about 50 “earth-like planets.” What that means is that they have found rocky planets in the habitable zone that are about the same size as Earth. Venus would qualify as an “Earth-like planet,” but it is an excellent example of how misleading that statement is. Venus has a thick crust with no sign of plate tectonics, no magnetic field, no way to recycle materials, and no stabilizing moon. Our Moon keeps the tilt of Earth’s axis at 23 ½ degrees providing a stable climate.
Realize that all of these factors are just to have a ball of rock in the right place at the right time with the right materials with which to make life. Now we would need to calculate the odds of getting the right chemicals together at the right time in the right place with the right catalyst to make the first living thing. Books have been written about how improbable those steps are. The writers are not religious fanatics, but scientists who are doing the research.
The Scientific American article, concludes that we are alone in the Milky Way:
“As we put everything together, what can we say? Is life likely to exist elsewhere in the galaxy? Almost certainly yes, given the speed with which it appeared on Earth. Is another technological civilization likely to exist today? Almost certainly no, given the chain of circumstances that led to our existence. These considerations suggest we are unique not just on our planet but in the whole Milky Way. And if our planet is so special, it becomes all the more important to preserve this unique world for ourselves, our descendants and the many creatures that call Earth home.”
When a person says that the mindless forces of evolution can easily explain everything that appears to be design in nature, you have to wonder if that person understands the principles of statistics.
From a statistical standpoint the more parameters that exist, the less likely it is that a desired final result will occur. The odds of a single coin flipped into the air and landing on heads is one in two or 1/2. What are the odds of five flipped coins landing heads up? That would be 1/2 multiplied by itself five times. The answer is one in thirty-two or 1/32. If you throw fifty coins up at the same time, the chance of all fifty showing heads is so small as to be considered impossible. (Multiply 1/2 fifty times.)
In nature, we see situations where the odds would be equivalent to throwing a million (or more) coins up and having them all land on heads. There is no way that an open-minded, thinking person can begin to entertain the idea that blind chance can explain such events.
Books and movies on nature often use a phrase like “nature planned…” or “evolution engineered…” or “genetic forces created…” some natural phenomenon. If you truly believe that the forces that created and designed the universe with our planet and everything on it are “mindless, blind, mechanistic chance,” then you can’t attach words that indicate wisdom, purpose, design, engineering, or creativity.
When astronauts landed on the Moon in the 1970s, they left several instruments behind that continued to send data to the Earth. Among those instruments was a set of temperature probes bored into the surface that measured how heat travels through the lunar soil. The data from those instruments indicate a fragile lunar temperature.
Scientists had assumed that heat flows out from the Moon’s core, just as it does on Earth. The question was how fast it was flowing and was this due to residual heat in the core of the Moon or due to radioactive decay inside the Moon. They were amazed to discover that heat was flowing into the Moon instead of out of it.
Later measurements showed that the heat flow into the Moon only happened where the astronauts had been walking and where the rover drove. Scientists now agree that the footprints of the astronauts and the tracks of the rover compressed the lunar sediment which darkened the print. Sunlight was absorbed more efficiently in the darkened areas. Thus it was the absorption of sunlight which caused the elevated temperatures in the borehole and made it appear that it was a lunar feature. A detailed treatment of this research appeared in the Journal of Geophysical Research: Planets in May of 2018.
We are only beginning to understand how delicate the creation process is. The fragile lunar temperature indicates that a small variation can alter the end product of the process. God’s creation of the cosmos demanded incredible knowledge of all this and continues to sustain it today.