The Bible is not a physics textbook. Its purpose is to reveal the relationship between God and humanity. Yet the Bible also contains a wealth of verifiable historical and scientific facts. Only in the 20th century, as human understanding of science began to expand, did we realize that the Bible’s descriptions not only harmonize with science but, in many cases, anticipated discoveries by more than 3,500 years. Still, Scripture does not dwell on these matters—its focus remains on God’s relationship with His people.

The Hydrologic Cycle

Take for example Ecclesiastes 1:7: “All streams flow into the sea, yet the sea is never full. To the place the streams come from, there they return again.”

The writer, King Solomon, was not attempting to teach science here but his point was: human life flows on, generation after generation. Just as rivers run endlessly into the sea, so human desire is never satisfied, leaving life empty and restless. This is a feeling we can still relate to today. Only in Christ can the human heart find true fulfillment.

From a scientific perspective, however, Solomon’s words also describe the hydrologic cycle. You may say, “Is that really the hydrologic cycle? Perhaps it’s just a poetic expression.” Indeed, Li Bai, the great Chinese poet, famously wrote: “The Yellow River comes from heaven, rushing to the sea, never to return.” He described water as “never returning,” without any cycle, but under the inspiration of the Holy Spirit, Solomon expressed the crucial truth: the water returns.

Modern science tells us that the transformation of water’s three states (solid, liquid, and gas) is the internal mechanism that produces the hydrologic cycle; and solar radiation and gravity provide the driving force for this process. The sun radiates an immense amount of heat energy, of which about 23% that reaches the earth is consumed in the evaporation of water from oceans, lakes, and soil. Each year, an estimated 577,000 cubic kilometers of water rise into the atmosphere, which then return to the ocean and land through precipitation as rain, snow, or hail. This cycle extends upward to the tropopause, about 11 kilometers above the surface, and downward to groundwater about a kilometer deep. In various forms, water circulates between atmosphere, land, and oceans.

A more detailed description of the process is as follows:

1. Evaporation: Solar radiation causes water to evaporate from the surfaces of oceans and land, and also to transpire from plants, turning into water vapor that becomes part of the atmosphere.

2. Transportation of vapor: Water vapor is carried by air currents from one region to another, or from lower altitudes to higher altitudes.

3. Precipitation: Water vapor in the atmosphere condenses under suitable conditions and, under the influence of gravity, falls to the earth in the form of rain, snow, or hail.

4. Runoff: During precipitation, some water evaporates and returns to the atmosphere, while some is intercepted by plants, infiltrates the ground, fills depressions, or stays temporarily on the surface. Eventually, through various routes, it becomes surface runoff, overland flow, or groundwater flow, converging into rivers and ultimately reaching lakes and seas.

It wasn’t until the 17th century in France that Pierre Perrault (a scientist) and Edme Mariotte (a physicist and plant physiologist) demonstrated the scientific reality of the water cycle. Yet Scripture had already alluded to it nearly three millennia earlier.

Noah’s Ark

Another striking example is Noah’s Ark. In Genesis 6, the earth was filled with violence and corruption, and humankind’s thoughts were continually evil. God resolved to bring judgment through a great flood, sparing only Noah and his family, because Noah “was a righteous man, blameless among the people of his time, and he walked faithfully with God” (Genesis 6:9). God gave Noah precise instructions for building the ark: “Make yourself an ark of cypress wood; make rooms in it and coat it with pitch inside and out. This is how you are to build it: The ark is to be three hundred cubits long, fifty cubits wide and thirty cubits high…” (Genesis 6:14–16). A cubit is about 18 inches.

The ark was a three-deck vessel roughly one and a half football fields long and four stories tall, with a length-to-width ratio of six to one, the same ratio used in modern ships. From a technical standpoint, it represents the most stable and safe design for a ship at sea. By contrast, until the 16th century, sailing ships were typically only twice as long as they were wide, making them unstable in rough waters. In 1594, Dutch merchant, Pieter Jansz Liorne, inspired by the proportions of Noah’s Ark, commissioned a vessel built with a four-to-one ratio and a flatter hull. The ship was a resounding success: it carried over three times the cargo of its competitors, required no extra crew, sailed faster, and remained more stable.

The relationship between science and faith remains one of the most debated and sensitive topics of our time. In his book, Song of a Wanderer, author Li Cheng classified people’s perspectives on science and faith into three categories:

1. Conflict: Science and faith are utterly opposed and mutually exclusive.

2. Separation: Faith exists only in areas where science has not yet reached.

3. Harmony: The Christian perspective: faith transcends science and is not in conflict with it, for the same God who created the universe also established its natural laws.

Scientists are not creators. They only explore and discover the natural laws that God has already established. As Dr. Francis S. Collins, former director of the Human Genome Project, once said: “I believe that science is the process of uncovering, one by one, the truths that God already knows.” Scientific discoveries are consistent with the natural laws God has created. God reveals Himself in nature through the patterns science discovers, and He reveals Himself in Scripture through the enlightenment of Holy Spirit. Together, these two forms of revelation complement each other and help us understand God’s creation and His mighty power.

Tielou Zhou is a retired professor of physics.