3 And God said, “Let there be light,” and there was light. 4 God saw that the light was good, and he separated the light from the darkness.5 God called the light “day,” and the darkness he called “night.” And there was evening, and there was morning—the first day.
There is debate sparked from assuming that this passage indicates the first light that God created was like the light we have today–separating the days. This implies that the sun, and all of the stars, were formed the first day. On the surface, such assumptions may seem obvious.
But it’s wrong.
Then, along came German physicist Max Planck, who discovered Planck’s Law. The law describes the spectral density of electromagnetic radiation emitted by a black body at a given temperature, which is also called black body radiation.
There are two kinds of matter: dark matter and everything else. God separated the matter, instead of it simply being lights on and off. Darkness is a substance and the absence of light, not a measurement of time.The two kinds of matter are separated, but present in different places all the time.
Swiss astronomer Fritz Zwicky discovered dark matter in 1933. This matter does not absorb light. Light passes through it, leaving it unchanged. It does, however, produce a gravitational force and may alter other objects.
Normal matter absorbs radiation and bounces it back.
Light interacts with electromagnetic waves, and dark matter does not. They both interact with gravity. What we see is just a tiny part of of the light, though. Electromagnetic radiation is emitted all around us, creating a constant cluster of waves–some visible, most invisible.
With this knowledge, light itself doesn’t measure time until the fourth day of creation in Genesis. The separation of light and darkness was a one time event.
The earth didn’t start rotating until the fourth day, creating what we know as day and night. This created what we use as time.