Exploring Space Radiation From Space Electromagnetic Spectrum Energy

Radiation From Space • Electromagnetic Spectrum • Energy leaves a star in the form

Speed of Light 300, 000 km / sec. 186, 000 mi / sec. In

Energy Waves • • • Crest – Top (highest point) of each wave Trough

Energy Waves (cont. ) • Passage of 1 wave = 1 cycle • 1

Light • Made up of all colors of the spectrum • Travels in a

Light • Reflect – the bouncing of light off the surface of a material

Prism: angular piece of glass used to produce a spectrum.

Colors • White – all colors reflected • Black – all colors absorbed –

What happens when you wear a black shirt on a hot summer day? Why?

Telescope (far. . see) Radio Telescopes Optical Telescopes

Telescope (far. . see) Radio Telescopes collects and focuses radio waves Optical Telescopes

Telescope (far. . see) Radio Telescopes collects and focuses radio waves Optical Telescopes collects

$Telescope (far. . see) Radio Telescopes Optical Telescopes Refracting: uses a lens to bend$

Focal Length Eyepiece Objective Lens focal point

Light rays from the eyepiece enter your eye before it crosses the focal plane,

Focal Length Eyepiece Objective Lens Magnification = F (objective) F (eyepiece)

Focal Length Eyepiece Objective Lens Magnification = 700 mm 15 mm

Focal Length Eyepiece Objective Lens Magnification = 46. 6 x

Focal Length Eyepiece Objective Lens Magnification = 700 mm 10 mm

Focal Length Eyepiece Objective Lens Magnification = 70 x

Focal Length Eyepiece Objective Lens Magnification = 700 mm 5 mm

Focal Length Eyepiece Objective Lens Magnification = 140 x

The ability to discriminate between two points is called what?

The ability to discriminate between two points is called what? Resolution

Amateur astronomer often prefer observing with lower magnification. . . it’s just more pleasing.

What is another advantage of a large lens or mirror?

What is another advantage of a large lens or mirror? Light Collecting Ability

What is another advantage of a large lens or mirror? Light Collecting Ability Imagine

Look at this view through a small telescope. Then click to the next slide

This view is the same magnification but much brighter!

Lens shapes biconvex biconcave plano-convex

Lens shapes biconvex plano-convex biconcave plano-concave

REFLECTING TELESCOPES “Schmidt -Cassegrain”

Slides: 137

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Exploring Space

Radiation From Space • Electromagnetic Spectrum • Energy leaves a star in the form of radiation • Transmitted by electromagnetic waves • Waves arranged according to wavelengths

Speed of Light 300, 000 km / sec. 186, 000 mi / sec. In a vacuum (space)

Energy Waves • • • Crest – Top (highest point) of each wave Trough – Bottom (lowest point) of a wave Wavelength – Distance between successive wave crests (troughs) Frequency – # of crests (troughs) that pass a point in 1 second Amplitude – distance between a wave’s mid point and its crest (trough)

Energy Waves (cont. ) • Passage of 1 wave = 1 cycle • 1 cycle / second = 1 hertz (Hz) _________ the wavelength = _________ frequency

Energy Waves (cont. ) • Passage of 1 wave = 1 cycle • 1 cycle / second = 1 hertz (Hz) The shorter the wavelength = _____ frequency _____ the wavelength = _____ frequency

Energy Waves (cont. ) • Passage of 1 wave = 1 cycle • 1 cycle / second = 1 hertz (Hz) The shorter the wavelength = Higher frequency _____ the wavelength = _____ frequency

Energy Waves (cont. ) • Passage of 1 wave = 1 cycle • 1 cycle / second = 1 hertz (Hz) The shorter the wavelength = Higher frequency The longer the wavelength = _____ frequency

Energy Waves (cont. ) • Passage of 1 wave = 1 cycle • 1 cycle / second = 1 hertz (Hz) The shorter the wavelength = Higher frequency The longer the wavelength = Lower frequency

Light • Made up of all colors of the spectrum • Travels in a straight path • Slows down as it travels through different substances

R O Y G. B I V

Light • Reflect – the bouncing of light off the surface of a material • Refract – the bending of light as it passes from one substance to another

Prism: angular piece of glass used to produce a spectrum.

Colors • White – all colors reflected • Black – all colors absorbed – You don’t “see” black – Sensation when very little light of any color reaches your eye • Green – green, blue, yellow reflected

Why do you see the colors that you see?

What happens when you wear a black shirt on a hot summer day? Why?

Rainbow Simulator

Telescope

Telescope (far. . seeing)

Telescope (far. . see) Radio Telescopes Optical Telescopes

Telescope (far. . see) Radio Telescopes collects and focuses radio waves Optical Telescopes

Telescope (far. . see) Radio Telescopes collects and focuses radio waves Optical Telescopes collects and focuses light rays

$Telescope (far. . see) Radio Telescopes Optical Telescopes Refracting: uses a lens to bend$

Telescope (far. . see) Radio Telescopes Optical Telescopes Refracting: uses a lens to bend light to a focal point Reflecting: uses a mirror to bounce light to a focal point

Focal Length focal point

Focal Length Objective Lens focal point

Focal Length Eyepiece Objective Lens focal point

Light rays from the eyepiece enter your eye before it crosses the focal plane, therefore the image is not corrected (re-inverted). Eyepiece Objective Lens

Focal Length Eyepiece Objective Lens Magnification = F (objective) F (eyepiece)

Focal Length Eyepiece Objective Lens Magnification = 700 mm 15 mm

Focal Length Eyepiece Objective Lens Magnification = 46. 6 x

Focal Length Eyepiece Objective Lens Magnification = 700 mm 10 mm

Focal Length Eyepiece Objective Lens Magnification = 70 x

Focal Length Eyepiece Objective Lens Magnification = 700 mm 5 mm

Focal Length Eyepiece Objective Lens Magnification = 140 x

Why pay for a bigger lens?

How many dots do you see?

Look closely.

The ability to discriminate between two points is called what?

The ability to discriminate between two points is called what? Resolution

Low Resolution High Resolution

47 x

47 x Now let’s see 150 x

150 x 47 x Same Resolution

Amateur astronomer often prefer observing with lower magnification. . . it’s just more pleasing.

What is another advantage of a large lens or mirror?

What is another advantage of a large lens or mirror? Light Collecting Ability

What is another advantage of a large lens or mirror? Light Collecting Ability Imagine the pupil of your eye dilated in the dark to a size of 8 or 16 inches!!

Look at this view through a small telescope. Then click to the next slide and compare with the same view through a larger telescope.

This view is the same magnification but much brighter!

Binoculars with 35 mm diameter lenses

Binoculars with 50 mm diameter lenses

Lens shapes Convex

Lens shapes Convex Concave

Lens shapes Convex Concave Plano

Lens shapes

Lens shapes biconvex

Lens shapes biconvex biconcave

Lens shapes biconvex biconcave plano-convex

Lens shapes biconvex plano-convex biconcave plano-concave