We use colors to express ourselves and admire their beautiful display in a rainbow when we see one. However, there is much more to colors than what can be observed with a naked eye. By studying their spectra with scientific methods, we can learn how they are created and many more interesting facts about their nature. Here is how the color spectrum is being studied and what we can learn from it.
Basics of Color Theory
The color of an object, as we can see it, is determined by chemical and physical factors. The electrons in a material interact with the light that’s shone onto them, resulting in a chemical reaction that creates transitional energy. This energy causes the light wave to be reflected in many different ways, which we physically perceive as different colors. The actual part of the spectrum we can observe is the result of another reaction – the one between the retina of our eyes and the visible light. Whatever the specific frequency range of the light falling onto the retina is, our eye will project it into the brain as a corresponding color.
What is a Color Spectrum?
Colors can be categorized by the wavelength of the light reflected from them. This occurrence is defined by the object’s physical properties, like light absorption and emission spectrum. Depending on the lighting, one object can produce a whole spectrum of colors – this is how rainbows are created. When a beam of light is broken down into its components, the different wavelengths form the rainbow.
When a material interacts with light, its physical attributes get imprinted on the light. As materials consist of atoms with different properties, a spectrum is like a specific fingerprint for each one of them. Each atom has a different number of electrons, which take up different positions inside them. The positioning and the movement of the electrons allow material to emit lights of different wavelengths. So essentially, by looking at a part of the spectrum reflected by an object, we can tell what it’s made of.
How is Spectrum Measured?
Every object absorbs and emits specific wavelengths of light that correspond to its distribution of electrons. We can measure the absorption spectrum and determine how the light is transmitted through a substance or the emission wavelength caused by the speeding up of the electrons. The most common method to study color spectrum is with a spectrograph – an instrument that catches the light in a telescope and then passes it through a small hole to isolate it. The light is then reflected from a specific grating and split into various wavelengths, resulting in a rainbow. This rainbow is then detected in a device that records each frequency that has been formed. If you want to learn more about this topic, the blog post What is Spectroscopy Used For? can give you a little more insight into how this method works and what makes it so useful. After all, spectroscopy is a well-established scientific method that has many other uses than just detecting rainbows. As beautiful as they are, the physical constitution of these natural phenomena is much more important to research than how we perceive them.
What Can We Learn From It?
By examining the intensity of light in each color, it can be determined how each frequency reacts with the physical constitution of the material when passing through it. As each natural element can appear in gaseous form, this property can be used to produce a series of colorful lines unique to that element. Analyzing the content of gases, we can determine the consistency and temperature of any material on Earth and even in space. In fact, until a couple of decades ago, the most notable use of spectroscopy was to determine the mass, temperature, and density of astronomical objects. With the advancement of this technology now we can utilize it to monitor the oxygen content of water ecosystems. By subjecting the tiniest bit of sample to spectroscopy, we can also study various tissues in human bodies. Observing the absorption spectrum of each tissue makes it much quicker to discover any malformation in them.
As you can see, studying spectra can have many benefits. From learning what an object of particular color consists of to understanding all of its other physical attributes – the uses of spectroscopy are virtually limitless. And while most of its uses are dedicated to everyday scientific purposes, some spectroscopy methods can help uncover answers to some age-old questions. So next time when you see a rainbow after a rain, think about how important this natural phenomenon is in our life.