The universe started with a bang nearly 14 billion years ago. The solar system formed 4.5 billion years ago. Even the continents have been around for a couple billion years. If, as Christians claim, humanity is so important to God, why did He wait so long to create the first people?
This question has different purposes, depending on the person asking. Skeptics usually want to argue that humanity is not central to anything. Instead, people represent the most recent event in a series of purely naturalistic processes (that presumably will continue long after our death). Young-earth creationists (YEC) usually want to argue that such long periods of time are inconsistent with God’s character and therefore didn’t actually occur.
So, how do billions of years fit within a context where humanity plays a central role in God’s creation?
Understanding God’s Physical Laws
It’s important to remember that if the God of the Bible exists, His sovereign nature means that He gets to set the standards and rules. God reveals through the Bible that He upholds and sustains the universe so reliably (for example, see Jeremiah 33:25–26) that we can describe the processes at work using the laws of physics. This reality brings two consequences. First, as a Christian and a scientist, my job is to study the universe to understand the way that God upholds and sustains creation. I don’t get to determine ahead of time what God should have done, but I am supposed to seek comprehension of what He did. Second, the reliability of the laws of physics should provide insight regarding why God waited billions of years to create humans.
Given the laws of physics that God chose to use, the universe would not support humanity until billions of years had passed. Four minutes after the universe started, it only contained hydrogen and helium. Life, even the primitive kind, needs multiple generations of stars (that “burn” for billions of years) to form the necessary amounts of carbon and oxygen. The existence of a complex, multicellular organism like human beings requires a planet meeting even more stringent conditions, such as a stable, long-lasting magnetic field.
Earth’s Remarkable Magnetic Field
Research indicates that Earth has had a strong magnetic field for much of its existence, but not the strong dipole character seen today (north and south poles closely aligned with the rotation axis). Recent studies indicate some significant changes in the strength and configuration during the last 2 billion years. Around 1.7 billion years ago, the magnetic field transitioned from a configuration with multiple poles to a dipole. Then 1 billion years ago, the field weakened and the poles became highly variable. Finally, 650 million years ago, right before the Cambrian explosion where abundant and diverse multicellular organisms appeared on Earth, it transitioned to the current strong dipole configuration.1 Furthermore, it appears that the transition back to the strong dipole regime may coincide with the formation of a solid inner core.
The variable and complex magnetic field configurations before 650 million years ago had little effect on life because this life resided almost exclusively in the water. After the Cambrian explosion, life appeared on the continents. Until the nucleation of the inner core occurred, Earth’s magnetic field would exhibit too much variability in strength and direction to provide the shielding that advanced, complex life like humans require.
Is Humanity Important?
So, can humanity be of central importance in the context of a 14-billion-year-old universe? Yes! Given the laws of physics that God chose to govern the universe, it took 9 billion years to form a planet capable of supporting life and 4.5 billion years to prepare that planet to host humans. Not everyone agrees that Earth represents the only planet capable of supporting human life, but the next few decades of exoplanet exploration will provide a wealth of data that will help to answer this question more definitively.
Just for kicks, here is one of my favorite demonstrations of neat things you can do with magnetic fields:
- Peter Driscoll, “Simulating 2 Ga of Geodynamo History,” Geophysical Research Letters 43 (June 2016): 5680–87, doi:10.1002/2016GL068858.