The rainbow is all in your head

If a tree falls in the forest and there is no one there to hear it, does it make any sound? The question may seem meaningless, but the answer can yield fascinating insights into the nature of sound, color, taste, beauty, love, and the Creator’s inventive genius.

When the tree falls, its branches push the air aside and strike other trees, finally smacking the ground with force. All these collisions of object against object or object against the air generate trains of wave forms that move out through the air. These traveling vibrations of molecules, or sound waves, in the air are controlled by precisely measurable physical laws. The size and nature of the colliding objects and the force with which they collide, control the shape and complexity of the sound waves that move through the air at a constant speed, precisely controlled by physical law. So it could appear that sound is entirely controlled by the laws of physics. However, that is a premature conclusion, because so far all we have described are vibrations of air molecules. How do these vibrations become sound?

The ear

As the tree falls, a logger is working nearby. The sound waves, or vibrating air molecules, cause his eardrum to vibrate, and this vibration is conveyed to the inner ear, where a long row of receptors respond to the vibrations. The receptors at one end of the row respond to long-wavelength vibrations, perceived by us as low-pitched sound. At the opposite end are receptors activated by short-wavelength vibrations, which humans perceive as highpitched sounds. In between are many other receptors, each tuned to respond to a specific band of intermediate wavelengths; and each receptor is connected to the brain by a nerve, which sends signals to the brain. The brain interprets the signals for us, allowing us to perceive the sound.

What type of signal travels along each of the nerves connecting an inner ear receptor to the brain? Is it sound, carried along the nerve? No, each nerve transmits only an electrical impulse or signal. The electrical signals from a long-wavelength receptor and the signals from a short-wavelength receptor are physiologically the same. Each inner-ear receptor has its own nerve connection to the brain. The only way the brain can tell if a signal indicates a long or a short-wavelength is by which nerve the signal comes through. So far we still have no sound–only vibrations of air molecules, and movement of electrical impulses along nerves.

Since the connection between ear and brain consists only of electrical impulses, the origin of the sound of a falling tree must come from somewhere within the brain. There was no sound traveling along the nerves–only electricity. Somehow, the brain receives the incoming pulses of electricity from numerous nerves, and translates them into the conscious perception we call “sound.” What we perceive as sound is strictly a sensation generated by the brain. The physical and chemical laws of nature govern the vibrations of air molecules and the interactions between molecules to make life possible, but life is much more than those laws. Life results from an highly complex organism that is not defined by those laws, just like the shape of your car is not controlled by the laws of nature, but had to be invented. Only the brain is able to produce the sensation of sound.

To illustrate why sound cannot be produced by those physical laws alone, compare the nerve connections from the ear with a computer keyboard. When we press a key with the letter M or G, an electrical signal is sent to the computer processor, where it is manipulated to produce the correct letter on the monitor. However, the letters M or G as they appear on the monitor are created inside the computer, and are controlled by the connections between keyboard and monitor. The electrical activity in a computer or in the brain would cease if it weren’t for physical laws, but the shape of the letters and which key they connect to are not controlled by any natural law–they were designed by an engineer. Thus a computer expert can easily change the connections so that pressing the M key results in a G appearing on the monitor.

In the same way, physical laws can’t determine which sound comes from which nerve; that is determined by arbitrary nerve connections from the ear. If we could reach into the brain and unplug the nerve cord from the ear to the brain, turn it around, and plug it in backwards, long-wavelength vibrations would be heard by us as high-pitched sounds, because that part of the brain that generates the sensation of high-pitched sound is being stimulated as a result of our having changed the wiring. A piccolo would sound like a tuba, and a tuba would be perceived as giving out piccolo sounds.

Vision: the eyes

Now we will move from the ears to the eyes. Light rays from the Sun bounce off all the objects around us. Some of those rays reach the light receptors in the back of our eyes, on the retina. The leaves on a tree absorb much of the light that strikes them, but the green light is reflected back. Those rays strike the retina, and we see the leaf as green. A red dress reflects the red rays, and our eyes are dazzled by the beauty of the bright red color, along with the beauty of the friend in the dress.

When a light receptor is triggered by a light ray, it sends a message to the brain. What type of message is that? It is an electrical impulse, of the same type as the electrical impulses sent by the ear in response to the vibrations it received. So if the same electrical impulses carry information about sound waves and light rays, why doesn’t our brain get confused? It isn’t confused for the same reason a computer knows the difference between a signal from the M key and a signal from the G key–the wires from those two keys go to different places in the computer. In the same fashion, nerves from the eye go to a specific place in the brain, a specific nerve for each visual signal. All the information from these nerves reaches the brain as electrical impulses, and the brain interprets the information as a visual image.

But because both long-wavelength and short-wavelength light rays communicate to the brain via the same type of electrical signals, the brain’s mode of interpreting those signals is the result of instructions (like computer software) in the brain, programmed to interpret the electrical signals from each part of the optical nerve and produce the correct visual image. In other words, our perception of red or green colors is the result of an information- processing system. Nothing in the laws of physics defines the characteristics of that system; it had to be invented by an intelligent designer.

You may object, stating that the wavelengths of light that produce various colors are well understood by physicists, and it is very predictable which wavelengths will be seen as each specific color. Yes, that is true, partly. The spectrum of visible light wavelengths is the result of precise physical laws, and the way in which those wavelengths are selectively reflected by different substances is a very consistent feature of nature. It is also true that we can predict which wavelength of light will be seen by us as green–usually. But the exceptions are a key to unraveling this puzzle. The fact that most of us see green in response to the same wavelength only confirms that the brain is very reliably programmed; we can count on it to see green the same way all the time. But it is not that way for everyone. Some people are color blind; they cannot tell the difference between red and green. When those individuals’ eyes are stimulated by light, do the laws of physics change? Of course not; the wavelengths of light reflected from tree leaves are still the same. The difference is in the interpretation occurring in their brains and optical systems, caused by defective instructions for interpreting red and green wavelengths.

Fortunately, color blindness is not a common problem, and in the majority of cases is limited to red and green. This tells us that the light-interpreting center in the brain is usually extremely stable and reliable, but it still appears to be dependent on the organization of the brain. In other words, the colors we perceive are not controlled by the laws of nature, but are the result of the way the Creator designed our brains. Color, as we perceive it, only exists in animal species whose brain generates those perceptions of color. Thus, the rainbow is all in our heads. If we invented a light-detecting instrument, it could measure only the wavelength of light, it would have no way of knowing what colors humans will perceive when their brains interpret those wave-lengths.

Now, remember the experiment we discussed before: unplugging the nerve cord from the ear and turning it around. However, this time, imagine we could unplug two nerve cords, one from the ear and one from the eye, and exchange them. Now the sound processor in the brain would receive electrical signals from the eye, and the visual processor would get its electrical signals from the ear. What would we see and hear? We would “hear light” and “see sound”! It would no doubt be very confusing, because the visual processor doesn’t have the right software to interpret sound information. However, we would see some type of pattern generated from the sound signals. We would also hear strange sounds!

The feeling of love

Think back to a memorable moment when you were standing hand in hand with someone you love, taking in the sounds and colors of a beautiful mountain scene. The feelings of love and companionship made the colors and sounds more vivid. Where did they come from? What laws of nature controlled those feelings, and the experiences, memories, and thoughts in your brain that were the foundation of those loving feelings? The tender touch of your loved one’s hand only stimulated touch receptors and sent electrical signals to specific places in the brain. Doesn’t sound very romantic, does it?

If that is where we stop, we understand physics and chemistry, but not love and romance. That experience of love cannot be described by the laws of physics or chemistry. True, laws of nature hold together the molecules that make up our body, making life possible. But only your brain was able to know the meaning of that particular touch, and to generate a unique feeling, different from what would have been produced in response to some other soft touch. Friendship, companionship, and love are a beautiful system of relationships that depend on the information analysis system invented by the Creator and placed in our brains, just like the brain centers that control our perception of sound and color.

We believe love exists because the Creator loves us and wanted us to experience relationships that go way beyond mere physics and chemistry; relationships that bring to us the kind of joy and romance that only a personal God understands and can share with us to brighten our lives. Love is an invention from God, programmed into our brains. Love, like the rainbow, is all in our heads.

The genius of our sensory world

Our entire sensory world of sounds, sights, colors, and smells (yes, smell involves the same concept) and the magic of love are produced by the information in a brain, not by the laws of sound or light waves. Next time you attend an orchestra concert, or sit at the edge of a forest in the evening, listening to the chorus of bird songs and watching the changing colors of the sunset blazing across the sky, think about the source of all this captivating sensory input. The varied instruments in the orchestra and the different types of bird songs are vibrating the air each in their unique way, and the sunset is reflecting light rays of varying wavelengths. That is all fascinating physics in its own right, but it doesn’t produce a symphony or make a gorgeous sunset! The captivating sound of the symphony and intoxicating colors of the sunset are produced only by a brain. They are gifts the Creator gave to us by way of the instructions and connections He programmed into our brain, which the brain uses to take coldly precise vibrations of air and translate them into something we perceive as exquisitely beautiful, an experience we want to share with someone we love.

If a tree falls in the forest, and there is no one there to hear it, does it make any sound? No, it vibrates the air, but sound is produced only inside a brain.

What does it all mean?

How did creatures come to have this sound, vision, smell, and romancegenerating equipment in their heads? For more than a hundred years, science has been explaining this as the result of mutation and natural selection– purely impersonal natural processes. In this article, we suggested a different interpretation, one that yields fascinating insights into the nature of sound, color, taste, beauty, love, and the Creator’s inventive genius that produced them. How can we be so sure we see the Creator’s hand at work? Actually we can’t prove it, just as no one can disprove it, but we believe it is a perfectly reasonable philosophical choice.

Science can contribute much toward understanding how our brains and other natural systems work and how organisms change. There is abundant evidence for microevolution and the emergence of new species, but there is a serious lack of convincing evidence for a genetic mechanism that could produce a new organ system or change one basic type of animal into another.* We cannot prove that a brain could not evolve without an intelligent designer, but naturalistic science carries the heavy burden of convincing us that it could happen. Even the very best science lacks the evidence to override, for many of us, the sense that the marvels of the human brain, for instance, would never appear without a wise designer who understands and invented such a sophisticated and exquisitely capable organ–an organ able to generate a symphony of sound and sight and of romance that delights us and makes life beautiful.

In the modern scientific worldview, the impersonal laws of chemistry and physics are the ultimate reality. But we believe God is a personal being, and in His universe personal relationships are of ultimate importance. God is the inventor of the laws of nature and is the master of those laws, and uses them consistently to run the universe. But they are not His ultimate reason for creating, or His most valued creation. To God, personal relationships, and the ability of friends to share their appreciation of the esthetic wonders of His created universe, are of more significance than natural law. The laws of nature are only His servants, to provide a universe to support the more important realm–living, reasoning beings who can experience relationships and respond to God’s love.

Humans can never comprehend God until we understand and accept His nature as a personal being to whom natural law is merely a means to support His highest priority in the universe–loving relationships between beings who can share those trusting relationships because they freely choose to do so.

Leonard Brand (Ph.D., Cornell University) teaches biology and paleontology and chairs the Department of Earth and Biological Sciences at Loma Linda University in Loma Linda, California, U.S.A. His email: Ernest Schwab (Ph.D., Loma Linda University) teaches anatomy and physiology at the School of Allied Health Professions, Loma Linda University. His e-mail: This article has been condensed from a longer essay published by the authors in Origins 58 (2005), pp. 45-56.

* See L. R. Brand, Faith, Reason, and Earth History (Berrien Springs, Michigan: Andrews University Press, 1997), and Beginnings: Are Science and Scripture Partners in the Search for Origins? (Nampa, Idaho: Pacific Press, 2006). See also L. Spetner, Not by Chance! Shattering the Modern Theory of Evolution (Brooklyn, New York: The Judaica Press, 1998).