Unit E5 Focus Words
wave
noun – a moving disturbance
Let's just stay put and wait for this wave to go by.
radiation
noun – the transferring of energy as waves
Too much of the wrong kind of radiation can kill you, but it's around us all the time!
transmission
noun – sending a signal (often using radio waves)
The new radio station began transmission earlier this year.
electromagnetic
adjective — combining electricity and magnetism
Electromagnetic waves can travel through the vacuum of space. That's why we can see the light of stars many light years away.
spectrum
noun – a range of things or characteristics
This lightbulb puts out a full spectrum of white light, because it emits all the colors from red to violet.
visible
adjective — able to be seen, especially by humans
The visible light part of the spectrum is very narrow, yet it colors the rich world of those of us lucky enough to see it.
frequency
noun – the rate at which something repeats over time
I go to this beach with some frequency, because the waves also come with great frequency. More waves, more surfing!
wavelength
noun – the distance in a wave between one crest and the next, or between two consecutive troughs
Waves with high frequencies also have shorter wavelengths.
medium
noun – a substance (like a solid, liquid, or gas) that the energy of a wave can travel through.
Electromagnetic waves don't need a medium to travel, so we can see them from across the vacuum of space.
analog
adjective — having a variable signal that is continuous in time and amplitude, in contrast with a digital signal
Some people prefer vinyl records over digital music because records store the music and play it back using an analog signal.
digital
adjective — represented by a system that stores data as 1s and 0s in discrete values (rather than a continuous spectrum), in contrast with the continuous nature of an analog signal
The invention of digital music formats made possible everything from compact discs to online music streaming.