Energy travels in the form of Electromagnetic Waves How does Energy Travel? Energy travels in the form of Electromagnetic Waves

Electromagnetic Energy Energy that radiates from the sun Electromagnetic spectrum = electromagnetic rays arranged in order by wavelength

Electromagnetic Energy Energy that radiates from the Sun. Electromagnetic energy that reaches the Earth is called: INSOLATION (incoming solar radiation)

Electromagnetic Energy Electromagnetic energy is diagramed in the format of the electromagnetic spectrum. Electromagnetic spectrum All of the electromagnetic waves arranged in order by  wavelength

What is wavelength?

Wavelength Wavelength is the distance from crest to crest of a wave.

Let’s Look at the Electromagnetic Spectrum: What do you notice about wavelength? Does it stay the same? What is happening?

Frequency of the Wave is changing: The number of crests that pass a given point in 1 second Units…Hertz

What is the relationship between Frequency and Wavelength? As frequency increases…wavelength (the distance between crest to crest)…? As frequency decreases…wavelength…?

Let’s Look at the Electromagnetic Spectrum: Identify the types of waves by increasing WAVELENGTH.

Gamma Rays: Highest Frequency Shortest wavelength Most Energy Doctors use gamma-ray imaging to see inside your body.  Gamma rays can kill living cells.  It is used in radiation treatment for cancer.   On Earth, gamma waves are generated by nuclear explosions, lightning, and the less dramatic activity of radioactive decay.

X-ray: Airport security uses it to see through your luggage. Medical: -A dentist uses X-rays to image your teeth. -A doctor uses X-rays to image your body.

Ultraviolet: Ultraviolet radiation is the reason skin tans and burns. -Increases the risk of DNA and other cellular damage in living organisms. -Our bodies use UV to produce Vitamin D. Used to sterilize equipment. Used to sanitize water. UV waves are invisible to the human eye, some insects, such as bumblebees, can see them. Similar to how a dog can hear the sound of a whistle just outside the hearing range of humans.

Visible Light: Our eyes detect visible light. We see Visible Light! Fireflies, light bulbs, and stars all emit visible light. ROY G. BIV =  Red Orange Yellow Green Blue Indigo Violet Our eyes interpret ROY G. BIV as White Light!

Infrared: Felt as Heat. Warm objects produce infrared. Night vision goggles pick up the infrared light.  Remote controls send pulses of infrared that sends a message to a device.

Microwave:  Microwave radiation will cook your popcorn in just a few minutes.  Used by fixed traffic speed cameras, and for radar, which is used by aircraft, ships and weather forecasters.

Radio Waves: Lowest Frequency Longest wavelength Least Energy These waves are emitted by radio stations, bringing your favorite tunes. Mobile phones and Wi-Fi use this frequency.

Humans only see the visible light portion of the spectrum. Major Concepts: All electromagnetic waves travel at the same speed…the speed of light. The electromagnetic waves differ only by wavelength.  Humans only see the visible light portion of the spectrum. 

REVIEW: NASA - Tour of the Electromagnetic Spectrum https://www.youtube.com/watch?v=HPcAWNlVl-8 CRASH COURSE #24 https://www.youtube.com/watch?v=jjy-eqWM38g

Now it is your turn to practice interpreting the Electromagnetic Spectrum: