Before the introduction of electric lights, the darkness of the night allowed people to observe the sky much more clearly. For thousands of years, people looked up at night and marveled at what they saw. Of course, they saw the Moon and stars, but they could also see other objects. Those included the “wandering stars,” which we know as planets, “shooting stars,” which we know as meteors, and occasional stars with tails, known as comets. But understanding the night sky was limited by the resolving power of human vision. Then something happened to create a revolution in astronomy.
The revolution began in 1609 when Galileo put some lenses together and made his first telescope. Still, it was limited to observing visible light. People assumed that the only light was what they could see with their eyes. After all, what other kind of light could there be? Then, in 1800, British astronomer William Herschel accidentally discovered infrared light. After that, scientists discovered ultraviolet, radio waves, microwaves, X-rays, and gamma rays in the following years.
Astronomers today use all of those forms of electromagnetic radiation or “light” to explore the universe. You might wonder why we can see only a tiny portion of the electromagnetic spectrum. There is a good reason for that. Electromagnetic radiation surrounds us. That includes natural radiation and all frequencies transmitted from radio, television, mobile phones, wi-fi, Bluetooth, and other sources. If we could see all of those electromagnetic frequencies, our vision would be more limited than what we experience in a dense fog.
In God’s wisdom, He limited our vision to the rainbow of colors we need to see the world. However, science has given us the ability to “see” the other frequencies of light, and that has opened up a new revolution in astronomy.
Radio waves were the first portion of the invisible spectrum astronomers used. In 1933, Karl Jansky, a young American radio engineer working for Bell Labs, was searching for the source of “hiss” that interfered with radio transmissions. He found that some of it came from sources outside our solar system. That led to using radio telescopes to explore the vast reaches of space through the new science of radio astronomy.
Microwaves are the next frequencies above radio waves, and astronomers first detected them using radio telescopes. When we hear the word “microwave,” we think of a way to cook our meals quickly, but in astronomy, microwaves help us learn about the early universe. In 1965, American astronomers Arno Penzias and Robert Wilson, working for Bell Labs, were trying to find the cause of noise picked up by a radiometer they were using. They thought it was a defect in the system, but they had accidentally discovered what scientists call cosmic background radiation. It’s energy left over from the cosmic creation event, or the “big bang.” The cosmic microwave background proved that the universe had a beginning, as the Bible clearly says in verse 1.
Sometimes “accidental” discoveries lead to our learning more about how God created and sustains the universe. The revolution in astronomy today involves all of the various portions of the electromagnetic spectrum, and we will continue to consider that tomorrow.
— Roland Earnst © 2023
