1. Electromagnetic Radiation
Chapter 24
Tools for Studying Space
Electromagnetic Radiation
Who is Stan Hatfield and Ken Pinzke

2. 24.1 The Study of Light Electromagnetic Radiation
The electromagnetic spectrum is all of the energy waves of radiation produced by the sun.
It is arranged by wavelength – the distance from the start of one wave to the start of another.
And frequencies – the number of waves per distance.

3. What is the relationship between wavelength and frequency?

4. Putting the
Electromagnetic
Spectrum to use

5. 24.1 The Study of Light Electromagnetic Radiation Visible Light
Visible Light is the very small section of the electromagnetic spectrum that the human eye can see.
Visible light is composed of the colors of the rainbow.
ROY G BIV

6. Wave or Particle?
Light’s motion is characterized by a property known as wavelength
BUT…
It also travels in particles:
A photon is a small packet of light energy.

7. 24.1 The Study of Light Spectroscopy
 Spectroscopy is the study of the properties of light that depend on wavelength.
Continuous Spectrum
An uninterrupted band of light emitted by an incandescent solid, liquid, or gas under pressure.
Absorption Spectrum
Produced by a cool gas under low pressure.
The gas absorbs the different wavelengths of light
Looks like it has dark lines on a rainbow background.
Emission Spectrum
Produced by a hot gas under low pressure
Looks light color lines on a black background.

8. Formation of Spectra Makes no sense without caption in book YouTube:
The
Electromagnetic
Spectrum
Makes no sense without caption in book

9. How can scientists determine the elements present in a star?
When the spectrum of a star is studied, the spectral lines act as “fingerprints.” These lines identify the elements present and thus the star’s chemical composition.
Emission Spectrum Samples

10. 24.1 The Study of Light
 The Doppler effect is the change in frequency of electromagnetic or sound waves caused by the movement of the source and the observer.

11. the Doppler Effect…
Doppler Animation
in astronomy, it is used to determine something in space is moving away from or toward Earth.
When an object is moving toward Earth, the frequency appears to increase, and it is called a blue shift.
But when it is moving away, or decreases, it is called a red shift.
Astronomers mainly study this shift in stars, galaxies and clouds.