Electromagnetic Spectrum

1
Chapter 28.1 Electromagnetic Spectrum
2
Scientists learn about the Universe by collecting
Wave- Energy from the Electromagnetic Spectrum
3
The Electromagnetic- Spectrum is a continuum
depicting the full range of Electromagnetic
Radiation, with the longest wavelength at one
end, and the shortest at the other.
4
Electromagnetic Radiation is energy in the form
of a Wave, resulting from the motion of electric
charges and the magnetic fields that they produce.
5
(No Transcript)
6
Electromagnetic Spectrum
Visible Light
7
Increasing Wavelength
Increasing Energy
8
Objects in space emit energy in several different
Frequencies and Wavelengths.
9
(No Transcript)
10
Wavelength
11
The Wavelength of a Wave
12
Blue Light
Red Light
The wavelength of each color of light is different
13
Frequency
14
The Spectroscope and the Visible Spectrum
When light passes through a prism and out again,
they are refracted, or bent, forming a band
called the Visible Spectrum.
15
Stars emit light that falls within the visible
spectrum.
Scientists use an instrument called a
Spectroscope to separate this starlight into its
colors so that it can be studied.
16
Spectroscopes break light into three different
types.

• Continuous Spectrum
• Emission Spectrum
• Absorption Spectrum

17
(No Transcript)
18
(No Transcript)
19
Emission Spectrum of Hydrogen
Absorption Spectrum of Hydrogen

• By studying these different spectra, and
  comparing the emission/absorption spectra of
  stars to those of gaseous elements in a lab,
  astronomers can determine the types of elements
  that make up the atmospheres of the stars that
  emitted the light.

20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
Solar Spectrum
24
The Doppler Effect
Scientists use Spectral Analysis to not only
determine what gases are present in stars, but
also how they are moving relative to the Earth.
This is possible because of a phenomenon called
the Doppler Effect.
25
Lets look at some examples of the Doppler Effect
that you have all experienced.
26
Fire Engine moving to the right, and toward
Person B
Fire Engine at Rest
Waves stretched
Waves compressed
Person B
Person A
27
(No Transcript)
28
(No Transcript)
29
The Doppler Effect also applies to Light.
Bright Line Spectrum
30
Dark Line Spectrum
31
Because of Doppler Shift, scientists have
determined that our Universe is expanding
32
(No Transcript)
33
(No Transcript)
34
Scientists have even been able to use Doppler
Shift to detect the wobble of Stars with
orbiting massive planets.
35
(No Transcript)
36
Galaxy moving toward -Light shifted toward Blue.
Galaxy moving away-Light shifted toward Red.
37
Stars emit energy in wavelengths that include
1. Visible Light2. Infrared3. Ultraviolet4.
X-Rays 5. Gamma Rays.
38
(No Transcript)
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
(No Transcript)
43
(No Transcript)
44
(No Transcript)
45
X-Ray Black Holes
46
The Sun viewed through different wavelengths
H Alpha
UV
Gamma
X-Ray
47
M82 IR
M82 Optical
M82 X-Ray
M82 Radio
48
Astronomer view Space through different types of
Telescopes
49
Optical Telescopes

1. Telescopes gather far more light than the unaided
   eye can gather.
2. Telescopes magnify images.

50
Refracting Telescope
Refracting Telescope- Uses two lenses. The
Lense, at the front of the tube, gathers light.
The Eyepiece magnifies the image collected by
the lense. (limited in size by tendency of large
lenses to bend)
51
(No Transcript)
52
Reflecting Telescope
Reflecting Telescope- Uses one large lense to
gather and focus light, then reflect the image to
a small mirror, then to an eyepiece on the side.
Since the lense is supported, reflecting
telescopes can be much larger.
53
(No Transcript)
54
Reflector Scopes
55
Galaxy viewed through Optical wavelengths
56
Radio Telescopes
(technical term for really big satellite dishes)
Used to detect energy waves given off at
frequencies lower than visible light.
57
Lovell Radio Telescope
58
Cambridge Radio Telescope
59
(No Transcript)
60
(No Transcript)
61
Aricebo Radio Telescope
62
(No Transcript)
63
(No Transcript)
64
Galaxy viewed through Radio wavelengths
65
Other Types of Telescopes
66
COBE (Cosmic Background Explorer)
67
Cosmic Background Radiation From Big Bang
68
Milky Way Galactic Center
69
(No Transcript)
70
(No Transcript)
71
(No Transcript)
72
Compton Gamma Ray Telescope
73
ASCA
74
ASCA X-Ray Pulsar
75
ASCA X-Ray Black Hole
76
(No Transcript)
77
(No Transcript)
78
(No Transcript)
79
(No Transcript)
80
(No Transcript)
81
Pillars of Creation Photographed by the Hubble
Telescope (shown left)
82
(No Transcript)
83
(No Transcript)
84
IRAS Infrared Observatory
85
IR Man!
86
Infrared Milky Way Galactic Plain
87
(No Transcript)