Study sets, textbooks, questions
Upgrade to remove ads
Intro to the Universe Midterm Review (Ch 2)
Terms in this set (51)
Light Travels through Empty Space at a Speed of Nearly __________.
The speed of light, abbreviated as c, was historically measured __________________.
over large, interplanetary distances.
Glowing objects, like stars, emit __________.
an entire spectrum of light
Sunlight is a mixture of all colors that can be spread out into a ____________.
Light travels in waves and is characterized by __________.
wavelength and its frequency
The electromagnetic spectrum of light includes ______, _______, ________, __________, _______, ______, and _________.
radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
Light has properties of both waves and particles where individual packets are called _______.
An object's temperature is revealed by ___________.
the most intense wavelength of its spectrum of light
__________ specifies the dominant wavelength of light emitted by objects and reveals their temperatures.
Astronomers use the Stefan-Boltzmann law to determine the temperature of an object by carefully measuring the ______________.
energy flux of light emitted.
An object's chemical composition is revealed by the ___.
unique pattern of its spectrum of light
A hot, dense object emits a _____________ covering all wavelengths.
A hot, transparent gas produces an _____________ containing bright lines
emission line spectrum
A cool, transparent gas in front of a light source that itself has a continuous spectrum produces an ________.
absorption line spectrum
______________ is the study of the unique pattern of spectral lines emitted by every chemical substance
Electrons can "jump" only to specific orbits within atoms _______________.
creating the particular sets of spectral lines.
An object's motion through space is revealed by the ___.
precise wavelength positions of its spectrum of light
The ____________ describes how an observed wavelength can be shifted due to the relative motion of an energy-emitting object.
An observed spectrum is ___________ when the distance between an object and an observer is increasing.
An observed spectrum is ___________ when the distance between an object and an observer is decreasing.
___________ use lenses, mirrors, and electronics to concentrate and capture incoming light for study
The ability of a telescope to capture light is a telescope's _____________ and is closely related to the telescope's diameter.
A ______ uses an objective lens to concentrate incoming light to a point that is a focal length from the lens
A telescope using a primary mirror to concentrate incoming light is called a ____________.
The magnification achieved by a telescope is accomplished by the ___________.
__________ is the ability of a telescope to see two glowing objects as distinct and separate light sources.
The new telescope technology of _____________, __________, and ___________ dramatically improves modern telescope performance.
charged-coupled devices (CCDs), adaptive optics, interferometry
Telescopes in orbit around Earth detect and resolve
light that does not penetrate the atmosphere.
Our eyes can only see a small band of the entire spectrum of light.
The Doppler effect is an important tool in astronomy because it uncovers basic information about the temperature of objects in space.
The wavelength of the maximum emission of an object depends only on the size of an object.
How much energy a star emits is determined by both temperature and surface area.
The atmosphere is transparent to most radio waves.
A blackbody curve graphs brightness of a star over time.
Radio waves travel through space at what speed?
At the speed of light, 3 × 108 m/s
Violet light differs from red light in that violet light
has a shorter wavelength than red light.
Which of the following is an electromagnetic wave?
On the absolute scale of temperature (in kelvins), the zero of the scale corresponds to the
temperature at which motions of atoms and molecules essentially cease.
The energy flux F from a star is the ________.
amount of energy emitted by each square meter of the star's surface each second.
The chemical makeup of a star's surface is obtained by
spectroscopy of the light emitted by the star.
If a certain gas is heated and observed through a grating, a bright line spectrum will be seen. If, instead, a source of continuous spectrum shines through a cooler sample of this same gas, a dark absorption spectrum is observed. How do the positions of the lines in these two spectra compare?
The lines in the two spectra will be at the same frequencies. They will be the same spectra.
The observed change in wavelength due to the Doppler effect occurs
only when the light source has a radial velocity (toward or away from the observer).
According to the Doppler effect, ________.
the wavelength of light is shifted to a shorter wavelength if the source of light is moving toward you.
The spectrum of a star shows an equivalent set of dark absorption lines to those of the Sun, with one exception: Every line appears at a slightly longer wavelength, shifted toward the red end of the spectrum. What conclusion can be drawn from this observation?
The star is moving rapidly away from Earth.
The major reason astronomers seek funds to build larger telescopes is to
To collect more light from distant objects.
Why was adaptive optics developed?
To compensate for image distortion caused by Earth's atmosphere.
Which part of the electromagnetic spectrum do mammals emit most strongly?
Earth's atmosphere is transparent and allows radiation to pass through
mostly in the visible and radio ranges of the electromagnetic spectrum.
For a telescope in space, above the distortion due to Earth's atmosphere, the angular resolution of the telescope
is better (can see finer detail) in blue light than in red light.
Which of the following objects is most likely to be studied in infrared light?
Dust disks around stars
Why is the sky blue?
The air molecules scatter blue light better than red light, so more blue light reaches our eyes.
Sets with similar terms
ASTR: Light - The Cosmic Messenger
Astr 101-Chapter 5 Questions
astro chapter 2
Other sets by this creator
IB Final Exam Review
Quiz 2 Study Guide
Asian Thought, Exam #1
FI 320 Midterm Equations
Other Quizlet sets
Biology ch 3 questions
History Chapter 2
Spanish 3 years chapter 2 conjugations -AR -ER
Blue Book Test