Wave Parts
This is the highest point reached by a wave.
What is the Crest?
If a wave has a very long wavelength, its frequency will be this.
What is Low?
These waves are the longest on the spectrum, comparable in size to buildings or humans.
What are Radio Waves?
This "barrier" around Earth blocks many waves like X-rays and Gamma rays from reaching the ground.
What is the Atmosphere?
Electromagnetic waves are unique because they can travel through this "empty" environment where there is no matter.
What is a Vacuum?
This is the lowest point reached by a wave.
What is the Trough?
This unit, abbreviated as Hz, is used to measure frequency.
What is Hertz?
These waves are roughly the size of a butterfly.
What are Microwaves?
This type of wave is used specifically to measure the speed of spinning dust in space.
What are Microwaves?
This acronym is used to remember the colors of the visible spectrum from longest to shortest wavelength.
What is ROYGBIV?
This term describes the number of waves that pass a given point per second.
What is Frequency?
In the visible spectrum (ROYGBIV), this color has the shortest wavelength and highest energy.
What is Violet?
This type of radiation is scaled to the size of a needle point.
What is Infrared?
Scientists use this type of radiation to scan "cool" objects like gas giants and nebulae.
What is Infrared?
These types of waves are "most blocked" by our atmosphere but are useful for determining the size of hot stars.
What is Ultraviolet (UV)?
While waves allow energy to travel across vast distances, they transfer this—not matter.
What is Energy?
This is the only type of wave that humans can naturally detect with their eyes.
What is Visible Light?
These high-energy waves are roughly the size of an atom.
What are X-rays?
To detect black holes and high-energy stars, astronomers look for this specific type of high-frequency wave.
What are Gamma Rays?
This tool (acronym VLBA) is used to show what objects would look like if we could see radio waves.
What is a Radio Telescope?
This measurement represents the maximum extent of a wave measured from its rest position.
What is Amplitude?
Because blue stars emit energy at shorter, high-energy wavelengths, they are considered this temperature compared to red stars.
What is Hottest?
These are the shortest waves on the spectrum, scaled to the size of an atomic nucleus.
What are Gamma Rays?
Apart from visible light, this is the only other wave type listed that can fully penetrate Earth's atmosphere to reach the ground.
What are Radio Waves?
These two factors (W and F) determine how all wavelengths in the EMS are arranged.
What are Wavelength and Frequency?