What Can a Light Spectrum Measure?
- Light is energy in the form of electromagnetic waves. It travels in a vacuum at 186,282 miles per second, which is also called light speed. Particles of light are called photons, which are like tiny pockets of pure energy. Optical light, the visible light we can see only represents a small portion of the electromagnetic spectrum. The full light spectrum actually represents the entire spread of photonic energy, which includes ultraviolet and even gamma radiation.
- Just like sonic vibrations, light energy travels in the form of waves. The various colors of the light spectrum visually represent the different frequencies of those light waves. For example, blue light has a higher frequency of vibration than red light. The blue wavelength is therefore shorter and travels from crest to trough much faster. This spatial distance is measured in nanometers and provides us with a way to measure light and spectra in concrete, scientific terms.
- Photosynthesis is one of nature's most powerful tools, which uses plants to transform solar radiation into organic compounds. Since this process provides basic energy for all life on earth, agricultural crop producers are greatly influenced by both the quality and quantity of light. The light spectrum can be used to provide optimal growing conditions for specific plants and even tell growers when to expect a sun shower. Spectrum Technologies gives a detailed listing of which areas of the light spectrum are ideal for growing conditions. According to the instrument manufacturers, photosynthesis is best achieved when plants are exposed to light in the 400 to 700 nanometer range. Exposure to other ranges of electromagnetic radiation can have definite effects on crop production, as well. For example, ultraviolet-blue light in the range of 315 to 400 nm can cause fungus sporolation and inhibit cell elongation.
- The atoms contained in molecules and chemical elements have the ability to absorb light. Each element has a specific energy configuration and therefore has a unique pattern of spectral absorption. The Department of Physics at Johns Hopkins University uses neon as an example. The atomic configuration of neon causes significant spikes in the yellow and red regions of the spectrum. This provides researchers with a fingerprint for each element, allowing them to retrieve data about the composition of matter based on the presence of energy.
- Astronomers use the light spectrum to find distant planetary bodies outside of our solar system. Basically, each planet has it's own spectral fingerprint based on the composition of elements in its atmosphere and on its surface. Light measurements can be used to screen out certain types of radiation interference to peer even farther into the void. Wired magazine recently reported that astronomers in the Chilean desert were able to use these principles to view a planet that is 129 light years away from Earth. The planet's temperature radiates at 1,000 degrees Celsius, which made it much easier for astronomers to detect it with infrared sensors.