In this fourth article on Our Amazing Moon we will examine how the moon’s orbital path both creates and regulates earth’s tides like clockwork several times daily. Our primary tidal motion is due to two major forces acting upon our planet – gravity and inertia. While the first acts to pull the oceans away from the Earth’s surface toward the Moon, the second reacts to pull the oceans away from the Earth’s surface opposite the Moon.
Lunar Mass and Tidal Bulging
An object’s mass and its distance from another object are all directly proportional to the gravitational effect it has on the second object. In simple terms, the more massive and the closer one object is to another, the more gravity (or ‘pull’) it will exert on the other object. This is particularly true regarding the Moon and our Earth.
In Article #2 of this series (Our Amazing Moon II: Size and Location) we examined the unique mass relationship between the Earth and the Moon and found that our Moon is many times larger in proportion to the Earth than any other moon is in our solar system when compared to its home planet. This significant Moon-to-Earth mass ratio gives our Moon enough gravity to ‘tug’ on our oceans as it orbits the Earth – ‘lifting’ the side facing the Moon away from the surface a bit.
The process described above is known as tidal bulging. The amount of tidal bulging that occurs on the earth is just enough to keep our oceans circulating at the proper rate for our ecosystem to flourish. If any of the parameters of the Moon’s orbit or mass were altered by a mere fraction of a percent, the resulting change in our tides could become catastrophic!
Inertia and Tidal Bulging
Tidal bulging does not only occur on the lunar-facing side of the earth. It also occurs on the exact opposite side as well. This is because the Earth is also pulled slightly toward the Moon as well, and the oceans on the side of the Earth opposite the Moon try to remain in place due to inertia. The peak point of the inertial force occurs on the side of the Earth directly opposite the Moon. An image depicting this action can be found at:
Inertia is Newton’s First Law of Motion and basically states that an object at rest will remain at rest –OR– an object in motion will tend to remain in motion in a straight line unless acted upon by an outside force.
Therefore, tidal bulging occurs on opposite sides of our planet at the same time and is constantly shifting with the orbit of the Moon.
Lunar Apsidal Orbit and Additional Factors
From the previous article in this series entitled: Our Amazing Moon III: Unique and Critical Orbit we saw that the angle of the Moon’s orbit changes about the Earth’s equator from any fixed point over time. This means that the plane along which the tidal bulge is raised will be constantly changing as well during the entire apsidal cycle.
We also learned that the orbit of the Moon is not perfectly circular, but slightly elliptical. This elliptical orbit means that the Moon is not always exerting the same amount of gravitational pull on our oceans since its distance is fluctuating slightly during each orbit.
These lunar effects along with those caused by the Sun’s gravity, the Earth’s rotation, internal oceanic forces, and other forces to numerous and extensive to cover in this article, all act to create the regular and complex tidal action that allows aquatic and all other life to thrive on our unique planet.
Created for a Purpose
Our planet has been clearly created for a purpose and all of the components on and around it, including our Moon, act together to maintain the environment necessary for us to survive and thrive here.
‘For thus saith the LORD that created the heavens; God Himself that formed the earth and made it; He hath established it, He created it not in vain, He formed it to be inhabited: I am the LORD; and there is none else.’ -Isaiah 45:18
The oceans were a key part of God’s creative plan from the beginning, and the day after He created them He put the items in place that would govern their actions until this very day.
‘And God called the dry land Earth; and the gathering together of the waters called He Seas: and God saw that it was good.’ (Day #3) ‘And God made two great lights; the greater light [Sun] to rule the day, and the lesser light [Moon] to rule the night: He made the stars also.’ (Day #4) -Genesis 1:10, 16
The hydrologic cycle is recorded in the book of Job nearly 1700 years before Roman Architect Marcus Vitruvius even proposed a theory of this now well-understood process.
‘For He maketh small the drops of water: they pour down rain according to the vapour thereof: Which the clouds do drop and distil upon man abundantly.’ -Job 36:27-28
In His Love,
Dr. Jack L. Burton
(1) NASA Planetary Fact Sheets and associated satellite data sheets.
(2) TheSky Astronomy Software © 1984-2000. Software Bisque, Inc.
(3) NOAA Ocean Service Education. Tides and Water Levels.
(4) NASA. Newton’s Laws of Motion.
- All Bible quotes in this article are taken from the KJV.
- Bible passages in double quotes (“) appear exactly as found in the KJV.
- Bible passages in single quotes (‘) have been modified for emphasis or ease of reading only (such as capitalization of pronouns referring to God, bolded text, or modernized punctuation, etc.) without altering the actual wording of the text.
Disclaimer: While to the author’s knowledge all of the information cited in the referenced material related directly to the content of this article is correct and accurate, the author in no way endorses any of the cited references in their entirety – especially where the material contained therein is in direct contradiction with the Creation account given in the Word of God.