Light waves throughout the electromagnetic spectrum behave in similar ways. When a light wave encounters one object, they are either sent , reflected, absorbed, refracted, polarized, diffracted, or scattered relying on the ingredient of the object and the wavelength that the light.

You are watching: What are three ways that waves change direction

Specialized instruments onboard spacecraft and airplanes collection data on exactly how electromagnetic tide behave as soon as they interact with matter. These data can reveal the physical and chemical ingredient of matter.



Reflection is when incident light (incoming light) hits things and bounces off. Really smooth surfaces such as mirrors reflect practically all incident light.

The shade of things is actually the wavelengths of the light reflected while all various other wavelengths room absorbed. Color, in this case, refers to the different wavelengths of light in the visible light spectrum regarded by our eyes. The physical and also chemical composition of issue determines i m sorry wavelength (or color) is reflected.

This reflective behavior of light is supplied by lasers onboard"s Lunar enlightenment Orbiter come map the surface ar of the Moon. The instrument measures the time the takes a laser pulse come hit the surface and also return. The longer the solution time, the farther away the surface and lower the elevation. A much shorter response time way the surface ar is closer or higher in elevation. In this photo of the Moon"s southerly hemisphere, short elevations are displayed as purple and also blue, and also high elevations are shown in red and brown.



Absorption occurs when photons from occurrence light hit atoms and also molecules and cause them to vibrate. The an ext an object"s molecule move and also vibrate, the hotter the becomes. This warmth is then emitted from the object as thermal energy.

Some objects, such as darker colored objects, absorb an ext incident light power than others. Because that example, black color pavement absorbs many visible and also UV energy and also reflects really little, while a light-colored concrete sidewalk reflects more energy than it absorbs. Thus, the black pavement is hotter than the sidewalk ~ above a hot summer day. Photons bounce roughly during this absorption process and shed bits of power to plenty of molecules follow me the way. This thermal power then radiates in the type of longer wavelength infrared energy.

Thermal radiation indigenous the energy-absorbing asphalt and roofs in a city deserve to raise its surface temperature through as lot as 10° Celsius. The Landsat 7 satellite image below shows the city of Atlanta together an island that heat compared to the surrounding area. Sometimes this warming the air above cities deserve to influence weather, i m sorry is referred to as the "urban heat island" effect.



Diffraction is the bending and spreading the waves roughly an obstacle. That is most pronounced once a light wave strikes an object with a size equivalent to its very own wavelength. One instrument called a spectrometer offers diffraction to different light into a range of wavelengths—a spectrum. In the situation of visible light, the separation of wavelengths v diffraction outcomes in a rainbow.

A spectrometer uses diffraction (and the subsequent interference) of light from slits or gratings to separate wavelengths. Pass out peaks of power at specific wavelengths have the right to then be detected and also recorded. A graph of these data is referred to as a spectral signature. Trends in a spectral signature aid scientists identify the physical condition and composition that stellar and also interstellar matter.

The graph below from the SPIRE infrared spectrometer onboard the ESA (European room Agency) Herschel space telescope reveals strong emission lines native carbon monoxide (CO), atomic carbon, and ionized nitrogen in Galaxy M82.

Scattering occurs when light bounces off an item in a selection of directions. The lot of scattering that takes ar depends top top the wavelength of the light and the size and also structure the the object.

The sky shows up blue thus scattering behavior. Light at much shorter wavelengths—blue and also violet—is scattered by nitrogen and oxygen together it passes with the atmosphere. Much longer wavelengths of light—red and also yellow—transmit with the atmosphere. This scattering of irradiate at much shorter wavelengths illuminates the skies with light native the blue and violet end of the clearly shows spectrum. Even though violet is scattered an ext than blue, the sky looks blue come us due to the fact that our eye are more sensitive come blue light.

Aerosols in the environment can likewise scatter light."s Cloud-Aerosol Lidar and also Infrared Pathfinder Satellite monitoring (CALIPSO) satellite deserve to observe the scattering that laser pulses come "see" the distributions of aerosols from resources such together dust storms and forest fires. The image listed below shows a volcano ash cloud drifting over Europe from an eruption that Iceland"s Eyjafjallajökull Volcano in 2010.

See more: How Many Sixths Are In A Whole ? How Many Sixths Make Up A Whole


Refraction is when light waves adjust direction together they pass from one medium to another. Light travels slower in air than in a vacuum, and also even slow in water. Together light travels right into a different medium, the adjust in rate bends the light. Various wavelengths the light space slowed at different rates, which causes them to bending at various angles. 

For example, as soon as the complete spectrum the visible light travels v the glass that a prism, the wavelengths space separated right into the colors of the rainbow.

Top of page | Next: Visualization: From energy to Image

CitationAPAMLA Mission Directorate. "Wave Behaviors" 2010. Nationwide Aeronautics and an are Administration.