Chapter 3 Quiz Flashcards
What is light made of? How does it move about?
light is made of PARTICLES. It moves about in WAVES. Photons, packets of vibrating electric and magnetic fields, all carry energy through space at the same speed in a vacuum
What is wavelength, frequency, and speed?
Wavelength- distance between two successive wave crests
frequency- number of wave crests that pass a given point per second
speed- wavelength x frequency
What is the speed of light? Is it constant or changing?
The speed of light is c= 3.0 x 10^5 km/s. speed is constant
What is the electromagnetic spectrum? What are the names of its various domains? How do you classify them using wavelengths and/or frequency?
full array of all types of electromagnetic radiation.
Domains are gamma rays, x-rays, Infrared radiation, visible light, ultraviolet radiation, micro waves, radio waves. Gamma rays have the shortest wavelengths, highest frequency, and most energy. adio waves have the longest wavelengths, lowest frequency, and least energy
What is a telescope and what is its primary function? What is the difference between the two kinds of telescopes?
An instrument to collect more light than human eye can gather on its own. their functions are collection more light (BRIGHTNESS), higher RESOLUTION, and MAGNIFY objects. refracting telescopes collect light through lense (old), reflection telescopes collect light from mirrors (new)
- How do telescopes affect the brightness, resolution, and magnification of the observed objects and how do these three properties relate to the way the telescope is built?
more light= larger brightness= more information. increasing exposure on a smaller mirror= brighter but not better resolution. higher magnification= higher resolution.
What are the four types of reflecting telescopes used today?
NEWTONIAN TELESCOPE- angle between the incoming light ray and the perpendicular = angle between the outgoing, reflected light ray and that perpendicular
CASSEGRAIN FOCUS- curved secondary mirror extends the focal point
NASMYTH AND COUDE FOCUS- third curved tertiary mirror to direct the light out of the side of the telescope
PRIME FOCUS- focal point in front of the primary mirror
- How does a telescope store what it focuses and what’s a CCD
Uses the focal point. Charge coupled device, 90% of photons, is a device for movement of electrical charge, usually from within the device to an area where the charge can be manipulated (rain water falls into each bucket before the computer reads it)
what is refraction (vs. reflection)?
refraction is the bouncing back of light from its normal path. reflection is the phenomenon of a light beam rebounding after hitting a surface
What does the atmosphere do to observing? What is Seeing? How are these problems corrected for?
Atmosphere is gas that moving and changing density, light is refracted, stars change brightness- twlinkling. seeing is how steady the atmosphere is. the solution is put the telescope about the atmosphere
what is a blackbody? what two examples did we use? why do we care?
a physical body that absorbs all electromagnetic radiation. a star and an iron rod
What is a Black Body curve? What is plotted in it? What does it basically tell us
The higher the temperature, the more light, the shorter the wavelength. intensity and wavelength are plotted.
- What is the difference between some Black Body curve and another Black Body curve of a higher temperature
the higher the temperature, the shorter the wavelength
what is the significance of what wien said?
wilhelm carl werner otto fritz franz wien: stars are nearly perfect blackbodies. the hotter the object, the shorter the wavelength, the higher frequency, the more energy
What are emission lines
light from a rarefied hot gas. colored line. generated in the lab
