Presentation is loading. Please wait.

Presentation is loading. Please wait.

24.1 The Study of Light. Electromagnetic Radiation  Includes gamma rays, X-rays, UV light, visible light, infrared radiation, microwaves, & radio waves.

Similar presentations


Presentation on theme: "24.1 The Study of Light. Electromagnetic Radiation  Includes gamma rays, X-rays, UV light, visible light, infrared radiation, microwaves, & radio waves."— Presentation transcript:

1 24.1 The Study of Light

2 Electromagnetic Radiation  Includes gamma rays, X-rays, UV light, visible light, infrared radiation, microwaves, & radio waves  Electromagnetic Spectrum  Classifies radiation according to wavelength & frequency  Photons – small packet of light energy  Copy diagram on pg. 674 fig. 1

3

4 Spectroscopy  The study of the properties of light that depend on wavelength  Continuous spectrum – produced by an incandescent solid, liquid, or gas under high pressure (emit when hot)  Absorption spectrum – produced when visible light is passed through a relatively cool gas under low pressure. (gas absorbs selected wavelengths of light)  Emission Spectrum – produced by a hot gas under low pressure (bright lines)  When the spectrum of a star is studied, the spectral lines act as “fingerprints”

5

6 The Doppler Effect  Occurs for both sound and light  Change in wavelength of a wave that is emitted from a source that is moving away or toward an object  Light source that is moving away = redder  Light source that is moving toward = blue  Doppler Effect is used to determine whether a star or other body in space is moving away from or toward Earth

7 REVIEW REVIEW REVIEW  What types of radiation make up the electromagnetic spectrum?  Compare the 3 types of spectra  How are the elements in a star determined?  How can the Doppler Effect tell detection?

8 24.2 Tools for Studying Space

9 Refracting Telescopes  Bend or refract light  Objective lens produces an image by bending light from a distant object so that the light converges at an area called the focus (central pt.)  Chromatic aberration ( color & to go astray)  Property of a lens whereby light of diff. colors is focused at diff. places (produces a halo around it)  Blue light is in focus = reddish halo  Red light is in focus = bluish halo

10 https://www.youtube.com/watch?v=VzSjqNE2AHM

11 Reflecting Telescopes  Chromatic aberration is avoided  Use a concave mirror that focuses light in front of a mirror rather than behind  Most large optical telescopes are reflectors  Light does not pass through a mirror so the glass for a reflecting telescope does not have to be of optical quality

12 https://www.youtube.com/watch?v=ic2aPxePlEs

13 Properties of Optical Telescopes  Both refracting & reflecting telescopes have 3 properties that help astronomers  Light gathering power  Resolving power  Magnifying power

14 Detecting Invisible Radiation  Radio telescopes – focuses the incoming radio waves on an antenna which absorbs & transmits these waves to an amplifier just like a radio antenna  Poor resolution (-)  Less affected by turbulence than optical telescopes (+)  Radio telescopes are hindered by human made radio interference (hidden in valleys to block these types of interference)

15 Space Telescopes  Orbit above Earth’s atmosphere & produce clearer images than Earth-based telescopes  Hubble Space Telescope  1 st space telescope built by NASA

16 REVIEW  How does a refracting telescope work?  Compare and contrast a refracting telescope and a reflecting telescope  How do radio telescopes gather data?  Why do space telescopes obtain clearer images than Earth based telescopes?


Download ppt "24.1 The Study of Light. Electromagnetic Radiation  Includes gamma rays, X-rays, UV light, visible light, infrared radiation, microwaves, & radio waves."

Similar presentations


Ads by Google