Transcript Chapter5-Questions

Question 1
Modern telescopes
use mirrors rather
than lenses for all
of these reasons
EXCEPT
1) Light passing through lenses can be
absorbed or scattered.
2) Large lenses can be very heavy.
3) Large lenses are more difficult to make.
4) Mirrors can be computer controlled to
improve resolution.
5) Reflecting telescopes aren’t affected by
the atmosphere as much.
Question 1
Modern telescopes
use mirrors rather
than lenses for all
of these reasons
EXCEPT
1) Light passing through lenses can be
absorbed or scattered.
2) Large lenses can be very heavy.
3) Large lenses are more difficult to make.
4) Mirrors can be computer controlled to
improve resolution.
5) Reflecting telescopes aren’t affected by
the atmosphere as much.
Reflecting instruments like
the KECK telescopes can
be made larger, and more
capable, than refractors.
Question 2
Resolution is
improved by
using
1) larger telescopes & longer wavelengths.
2) infrared light.
3) larger telescopes & shorter wavelengths.
4) lower frequency light.
5) visible light.
Question 2
Resolution is
improved by
using
1) larger telescopes & longer wavelengths.
2) infrared light.
3) larger telescopes & shorter wavelengths.
4) lower frequency light.
5) visible light.
Diffraction limits resolution; larger telescopes &
shorter wave light produces sharper images.
Question 3
Diffraction is the
tendency of light
to
1) bend around corners and edges.
2) separate into its component colors.
3) bend through a lens.
4) disperse within a prism.
5) reflect off a mirror.
Question 3
Diffraction is the
tendency of light
to
1) bend around corners and edges.
2) separate into its component colors.
3) bend through a lens.
4) disperse within a prism.
5) reflect off a mirror.
Diffraction affects all
telescopes and limits
the sharpness of all
images.
Question 4
An advantage of
CCDs over
photographic
film is
1) they don’t require chemical development.
2) digital data is easily stored & transmitted.
3) CCDs are more light sensitive than film.
4) CCD images can be developed faster.
5) All of the above are true.
Question 4
An advantage of
CCDs over
photographic
film is
1) they don’t require chemical development.
2) digital data is easily stored & transmitted.
3) CCDs are more light sensitive than film.
4) CCD images can be developed faster.
5) All of the above are true.
Question 5
“Seeing” in
astronomy is a
measurement
of
1) the quality of the telescope’s optics.
2) the transparency of a telescope’s lens.
3) the sharpness of vision of your eyes.
4) the image quality due to air stability.
5) the sky’s clarity & absence of clouds.
Question 5
“Seeing” in
astronomy is a
measurement
of
1) the quality of the telescope’s optics.
2) the transparency of a telescope’s lens.
3) the sharpness of vision of your eyes.
4) the image quality due to air stability.
5) the sky’s clarity & absence of clouds.
Smeared overall
image of star
“Good Seeing” occurs when
the atmosphere is clear and the
air is still.
Turbulent air produces “poor
seeing”, and fuzzier images.
Point images of a star
Question 6
“Adaptive Optics”
refers to
1) making telescopes larger or smaller.
2) reducing atmospheric blurring using
computer control.
3) collecting different kinds of light
with one type of telescope.
4) using multiple linked telescopes.
Question 6
“Adaptive Optics”
refers to
1) making telescopes larger or smaller.
2) reducing atmospheric blurring using
computer control.
3) collecting different kinds of light
with one type of telescope.
4) using multiple linked telescopes.
Shaping a mirror in
“real time” can
dramatically improve
resolution.
Question 7
Radio Telescopes
are useful because
1) observations can be made day & night.
2) we can see objects that don’t emit
visible light.
3) radio waves are not blocked by
interstellar dust.
4) they can be linked to form
interferometers.
5) All of the above are true.
Question 7
Radio Telescopes
are useful because
1) observations can be made day & night.
2) we can see objects that don’t emit
visible light.
3) radio waves are not blocked by
interstellar dust.
4) they can be linked to form
interferometers.
5) All of the above are true.
The Very Large
Array links separate
radio telescopes to
create much better
resolution.
Question 8
Radio
dishes are
large in
order to
1) improve angular resolution.
2) give greater magnification.
3) increase the range of waves they can collect.
4) detect shorter waves than optical telescopes
for superior resolution.
Question 8
Radio
dishes are
large in
order to
1) improve angular resolution.
2) give greater magnification.
3) increase the range of waves they can collect.
4) detect shorter waves than optical telescopes
for superior resolution.
Resolution is worse with
long-wave light, so radio
telescopes must be large
to compensate.
Question 9
Infrared telescopes
are very useful for
observing
1) pulsars & black holes.
2) from locations on the ground.
3) hot stars and intergalactic gas.
4) neutron stars.
5) cool stars and star-forming
regions.
Question 9
Infrared telescopes
are very useful for
observing
1) pulsars & black holes.
2) from locations on the ground.
3) hot stars and intergalactic gas.
4) neutron stars.
5) cool stars and star-forming
regions.
Infrared images of starforming “nurseries” can
reveal objects still shrouded
in cocoons of gas and dust.
Question 10
The Hubble Space
Telescope (HST) offers
sharper images than
ground telescopes
primarily because
1) HST is closer to planets & stars.
2) HST uses a larger primary mirror.
3) it gathers X-ray light.
4) HST orbits above the atmosphere.
5) it stays on the night-time side of
Earth.
Question 10
The Hubble Space
Telescope (HST) offers
sharper images than
ground telescopes
primarily because
1) HST is closer to planets & stars.
2) HST uses a larger primary mirror.
3) it gathers X-ray light.
4) HST orbits above the atmosphere.
5) it stays on the night-time side of
Earth.
HST orbits less than 400
miles above Earth – not much
closer to stars & planets!
But it can gather UV, visible,
& IR light, unaffected by
Earth’s atmosphere.