Tuesday, May 28, 2019

The Magnificent Moon

The earth is unique in our solar system, being the only planet that has one single large moon. Over the last few decades scientists have realized that our moon plays a significant role in order for the earth to support complex life forms. The gravitational pull of the moon on the earth is responsible for high and low ocean tides, which bring nutrients to tidal flood zones and allow for a diverse and thriving ecosystem near coastal regions. Tides also play a role in a global temperate climate because they affect ocean currents that move water around the globe.

Perhaps the most important feature of the earth-moon system is the relatively large gravitational pull of the moon, which stabilizes the tilt axis of the earth. The earth rotates around an axis that is tilted about twenty-three degrees from a line drawn perpendicular to the plane of its orbit. Because the earth's axis is tilted, we have various seasons: summer, spring, winter, and fall. When the earth’s orbit is on one side of the sun and it is tilted in such a way that the northern hemisphere gets direct sunlight, then it is summer in the northern hemisphere and winter in the southern hemisphere. When the earth is on the other side of the sun so its tilt gives direct sunlight to the southern hemisphere the seasons are reversed.

Saturday, May 11, 2019

A Primer on Various Views About Origins

The Bible is very clear about the fact that God created the universe and that humans were created by God in his image, a distinction that separates humans from all the other animals. On the other hand, the Bible is not clear on when and how God created the universe and humans. Consequently, even among Christians who believe the Bible is the inspired and inerrant word of God there is a difference of opinion about the methods God used to create the universe.

Sometimes it is valuable to review the very basic ideas about a topic. One of my readers asked me if I could very simply describe each of the major views held by Christians about how and when God created the universe and humans. I am answering that question with this basic primer about views on origins held by Christians and non-Christians. These can be broadly classified into four categories by answering three questions: (1) Did God create the universe and humans? (2) Did the big bang occur? and (3) Does macroscopic evolution occur?

The first question is straightforward. Is God the ultimate creator of the universe and human life? The second question has to do with the origin of the universe. Did this universe come into existence about 14 billion years ago and did the planet earth form about 4.5 billion years ago? The third question asks whether or not macroscopic evolution is the mechanism by which all species came into existence. Although most evolutionists do not distinguish between microscopic and macroscopic evolution, that distinction is necessary when discussing origins. Microscopic evolution allows small changes within species. It is the process of minor genetic change that allows things like bacteria to become resistant to certain antibiotics. When distinguished from macroscopic evolution, microscopic evolution does not produce new species or major new functionality. The process of microscopic evolution is accepted by people in all four categories. Macroscopic evolution is the claim that all life has developed from previous common ancestors through a natural process in which those small genetic changes compound and eventually form new species and new functionality.