Understand the electromagnetic spectrum and how it is organized. Understand what different types of electromagnetic radiation can reveal about astronomical objects. Understand and describe important properties of electromagnetic radiation. Understand how technology is used to collect electromagnetic radiation and turn it into images. Understand what can be learned from analyzing the light from astronomical objects. Understand how different types of lenses and telescopes work Understand and describe the quantization of energy at the atomic level Understand that all objects emit and absorb electromagnetic radiation and distinguish between objects that are blackbody radiators and those that are Qualitatively describe the shift in frequency in sound or electromagnetic waves due to the relative motion of a source or a receiver

Properties of Light(waves) Wavelength, frequency, and speed Properties of Light(waves) I hope a lot of this will be a review

Before we can go further talking about light waves….Gravity Waves! We have been looking for 100 years Just announced last year Being called the greatest scientific discovery this century Equal to the discovery of the telescope in terms of astronomers learning about the universe

https://www.youtube.com/watch?v=72AQsQ2v5cA

Brian Green – Really Smart Guy https://www.youtube.com/watch?v=s06_jRK939I

Today’s question: What are the properties of electromagnetic waves? Next year, we could be asking “what are the properties of gravitational waves, and what sort of things can we see/learn from them?”

You will need calculators today

ALL Waves are nothing more than…… ENERGY moving from one place to another! Not this kind….

What do waves travel through? Ocean Waves: the surface of the sea is vibrating up and down. Sound Waves: air? particles are vibrating. All electromagnetic waves can travel in a vacuum. Electromagnetic waves are vibrations of magnetic and electric fields. They don't need air or anything in order to travel.

All of these are electromagnetic waves.  This means that although they appear to be very different, in fact they're all the same - but at different frequencies and wavelengths.

wavelength means pretty much what it says - the length of one wave. To measure it more precisely, we use the distance from the peak of one wave to the peak on the next wave.  *technically, the distance from any point on a wave to the same point on the next cycle of the wave. The peaks are just handy places to measure from. It may be measured in: Kilometers km (1,000 meters) Meters m Centimeters cm (1/100 of a meter) Millimeters mm (1/1000 of a meter) The tiny lines on your ruler! Nanometers nm (1/1,000,000,000 of a meter)

frequency In math, how often something happens With waves, it's the number of waves that pass a point in a second It may be measured in: Hertz Hz 1 Hz : 1 wave per second Kilohertz kHz 1 kHz:1,000 waves per second Megahertz MHz 1 MHz:1 million waves per second.  (FM radio stations usually broadcasts around 100 MHz) Gigahertz GHz 1 GHz:1,000 million waves per second.

Describe the properties of this wave. Frequency: high or low? Wavelength: long or short? Energy: high or low?

Describe the properties of this wave. Frequency: high or low? Wavelength: long or short? Energy: high or low?

How fast do waves travel? All electromagnetic waves travel at the speed of light (c) The speed of a wave is the product of its wavelength and frequency. v = λ X f = c v = d/t v= speed (velocity) v= speed (velocity) λ = wavelength d=distance f= frequency t = time C = speed of light

the speed of light Also now the speed of gravity!

Problem 1 A tsunami wave travels at 150 kilometers/hour as it approaches land. If the wavelength is 50 kilometers, what is the frequency of the wave in Hertz? v = λ X f

Problem 1 A tsunami wave travels at 150 kilometers/hour as it approaches land. If the wavelength is 50 kilometers, what is the frequency of the wave in Hertz? v = λ X f 150 = 50 X f

Problem 2 A sound wave travels at 350 meters/sec, with a pitch (frequency) of 500 Hertz. What is its wavelength? v = λ X f

Problem 2 A sound wave travels at 350 meters/sec, with a pitch (frequency) of 500 Hertz. What is its wavelength? v = λ X f 350 = λ X 500

Problem 3 A sunbather on Cocoa Beach is passing her time by counting waves as they break on the beach. She watches as one distant wave takes 10 seconds to travel about 100 meters to the shore. What was the speed of this wave in meters per second?

Problem 3 A sunbather on Cocoa Beach is passing her time by counting waves as they break on the beach. She watches as one distant wave takes 10 seconds to travel about 100 meters to the shore. What was the speed of this wave in meters per second? v = d/t V= 100/10

Answer Today’s question: What are the properties of electromagnetic waves?

On Google Classroom Due Tomorrow (Thursday)

https://www.youtube.com/watch?v=DoOPEPVYAnU