Smartwork Chapter 1,5,6
Focal Length
Distance from lens to focal plane
Interferometer
Several telescopes connected to act as one
Which of the following is the biggest disadvantage of putting a telescope in space?
Space telescopes are much more expensive than similar ground-based telescopes.
The bright, colorful "stripes" of a rainbow such as the one shown here follow a particular order. Rank each color of the rainbow by how much energy is carried by its electromagnetic waves, from highest to lowest.
- Blue - Yellow - Orange - Red
Rank the types of radiation in order of their energy, from least to greatest.
- Radio waves - Infrared - Red visible light - blue visible light - x-rays - gamma rays
Rank the following in order of decreasing wavelength.
- Radio waves - Infrared - Visible - Ultraviolet - Gamma Rays
Today's astronomers have a broad array of technological tools for capturing astronomical data. Early astronomers lacked that advantage. Place the following types of astronomical equipment in the order that they became available.
- Refracting telescope - Reflecting telescope - Film Photography - Radio telescope - CCD Imaging
The largest astronomical refractor has an aperture of 1 meter. Select all true statements below about why it would be impractical to build an even larger refractor with, say, twice the aperture.
- The degree of chromatic aberration increases as the focal length gets longer, and this would reduce image quality. - The tube would have to be so long that housing and moving it would be extremely difficult, especially because it would be frontloaded with weight. - A lens with a 2 m diameter would be very heavy and would deform under its own weight within a few years.
Astronomers may describe certain objects as being redshifted or blueshifted. Select all true statements about this phenomenon from those listed below.
- These objects are exhibiting the Doppler effect. - Wavelengths of light from the objects differ from expected (rest) wavelengths because the object is moving away from (redshifted) or toward (blueshifted) the observer.
Building effective detectors for particles or waves that scientists would like to study is a real challenge. Some are easily detected, while others are not. Rank the following items in order of increasing difficulty of detection.
- infrared photons - neutrinos - gravity waves
Improved resolution is helpful to astronomers because it enables them to view
- small features of an object - very distant objects - many objects close together
Choose all that apply. CCD cameras are better astronomical detectors than the human eye because
- their quantum efficiency is higher - they can observe at wavelengths beyond the visible - the integration time can be longer
According to the scientific method, choose all of the following statements that are correct.
-A theory has a higher probability of accurately modeling a natural phenomenon than a hypothesis does -All theories have enough supporting evidence behind them that we can move forward under the assumption that they are correct unless some future test proves that this is not the case.
Resolution
Ability to distinguish objects that appear close together in the sky
If we compare our place in the universe with a very distant place, we can say that:
All of the laws of physics are the same in each place.
When you look at the sky on a dark night and see stars of different colors, which are the hottest?
Blue
How does the spectrum of a distant star reveal the star's chemical composition?
Dark lines, also called absorption lines, within the spectra are "fingerprints" for the different atoms and molecules within a star's atmosphere.
Identify each of the following six planets and order them by distance from the Sun. You may need to scroll right to view all of the images.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
You are shopping for telescopes online. You find two in your price range. One of these has an aperture of 20 cm, and one has an aperture of 30 cm. Which should you choose, and why?
The 30 cm, because the light-gathering power will be better.
When an electron moves from a higher energy level to a lower energy level in an atom,
a photon is emitted.
The angular resolution of a ground-based telescope is usually determined by
atmospheric seeing
Light acts like
both a wave and a particle.
As wavelength increases, the energy of a photon __________ and its frequency __________.
decreases; decreases
Cameras that use adaptive optics provide higher spatial-resolution images primarily because
deformable mirrors are used to correct the blurring due to Earth's atmosphere.
Aperature
diameter
A light-year is a measure of
distance
The scientific method is a way of trying to ______________ ideas; thus all scientific knowledge is provisional.
falsify, not prove,
Arrays of radio telescopes can produce much better resolution than single-dish telescopes because they work based on the principle of
interference
The cosmological principle states that
on a large scale, the universe is the same everywhere at a given time.
Two stars are of equal luminosity. Star A is 3 times as far from you as star B. Star A appears _________ star B.
one-ninth as bright as
chromatic aberration
rainbow-making effect
Diffraction
smearing effect due to sharp edge
When less energy is radiated from a terrestrial planet, its __________ increases until a new __________ is achieved.
temperature; equilibrium
"We are stardust" means that
the atoms in our bodies have passed through (and in many cases formed in) stars.
Spacecraft are the most effective way to study planets in our Solar System because
they can collect more information than is available just from images.
Understanding in science means that
we are able to connect facts through an underlying idea.
