Lens Inquiry
A CfAO/ISEE Designed Laboratory
Hartnell Community College
September 2009
Inquiry
• Inquiry is modeled on how scientists actually
perform their research
• You will become the expert on your topic of
investigation and will share your findings with the
class.
• Inquiry can be challenging, but it can also be
rewarding.
Activity Timeline
6:00-6:10
Introduction
6:10-6:25
Demos involving Lenses and Starters
6:25-6:40
Discussion of Vocab and Generate Questions
6:40-6:45
Choose question to investigate and form groups (2-3 people)
6:45-7:30
Focused Investigation
7:30-7:45
Make a poster to summarize your findings
7:45-8:15
Sharing out: each group will have 2 minutes to present
8:15-8:25
Converging Lenses Synthesis
8:25-8:45
Telescope Activity
8:45-8:50
Final Synthesis
Activity Timeline
6:00-6:10
Introduction
6:10-6:25
Demos involving Lenses and Starters
6:25-6:40
Discussion of Vocab and Generate Questions
6:40-6:45
Choose question to investigate and form groups (2-3 people)
6:45-7:30
Focused Investigation
7:30-7:45
Make a poster to summarize your findings
7:45-8:15
Sharing out: each group will have 2 minutes to present
8:15-8:25
Converging Lenses Synthesis
8:25-8:45
Telescope Activity
8:45-8:50
Final Synthesis
Why Use Telescopes?
1. To see more detail in bright objects
Jupiter
•
Uranus
Image Credits: Jupiter NASA, ESA, M. Wong (Space Telescope Science Institute, Baltimore,
MD), H. B. Hammel (Space Science Institute, Boulder, CO), and the Jupiter Impact Team,
Uranus L. Sromovsky (Univ. Wisconsin-Madison), Keck Observatory
Why Use Telescopes?
2. To see objects that are too faint to detect using only
your eyes
The Hubble
Ultra Deep Field
•
Image Credit: Hubble Ultra Deep Field S. Beckwith & the HUDF Working Group (STScI), HST,
ESA, NASA
State-of-the Art Famous
Telescopes
The Hubble Space Telescope Keck: 10m Reflecting Telescopes
2.4m Primary Mirror
To understand how telescopes
work, we will concentrate on
a particular type of telescope
called a refracting telescope
that uses lenses.
Refracting Telescopes Located Nearby
36 inch Refractor at
Lick Observatory
(1888)
20 inch Refractor at Chabot
Space and Science Center
(1914)
What’s Inside?
• This simple
telescope is made
up of two lenses.
• To simplify the
problem we would
like for you to
learn how a single
lens works in an
inquiry activity.
Activity Timeline
6:00-6:10
Introduction
6:10-6:25
Demos involving Lenses and Starters
6:25-6:40
Discussion of Vocab and Generate Questions
6:40-6:45
Choose question to investigate and form groups (2-3 people)
6:45-7:30
Focused Investigation
7:30-7:45
Make a poster to summarize your findings
7:45-8:15
Sharing out: each group will have 2 minutes to present
8:15-8:25
Converging Lenses Synthesis
8:25-8:45
Telescope Activity
8:45-8:50
Final Synthesis
At the Demo Stations
• In your Lab Manual, under Starters:
– Record any words that describe what you see
under Question 1
– Record any questions you have about the
phenomena you observe under Question 2
Activity Timeline
6:00-6:10
Introduction
6:10-6:25
Demos involving Lenses and Starters
6:25-6:40
Discussion of Vocab and Generate Questions
6:40-6:45
Choose question to investigate and form groups (2-3 people)
6:45-7:30
Focused Investigation
7:30-7:45
Make a poster to summarize your findings
7:45-8:15
Sharing out: each group will have 2 minutes to present
8:15-8:25
Converging Lenses Synthesis
8:25-8:45
Telescope Activity
8:45-8:50
Final Synthesis
Once you have chosen a Question
to Investigate
• In your Lab Manual, under Investigation:
– Answer Questions 1 and 2
– Use the space provided to keep track of any
notes or observations as your investigation
progresses.
Activity Timeline
6:00-6:10
Introduction
6:10-6:25
Demos involving Lenses and Starters
6:25-6:40
Discussion of Vocab and Generate Questions
6:40-6:45
Choose question to investigate and form groups (2-3 people)
6:45-7:30
Focused Investigation
7:30-7:45
Make a poster to summarize your findings
7:45-8:15
Sharing out: each group will have 2 minutes to present
8:15-8:25
Converging Lenses Synthesis
8:25-8:45
Telescope Activity
8:45-8:50
Final Synthesis
Activity Timeline
6:00-6:10
Introduction
6:10-6:25
Demos involving Lenses and Starters
6:25-6:40
Discussion of Vocab and Generate Questions
6:40-6:45
Choose question to investigate and form groups (2-3 people)
6:45-7:30
Focused Investigation
7:30-7:45
Make a poster to summarize your findings
7:45-8:15
Sharing out: each group will have 2 minutes to present
8:15-8:25
Converging Lenses Synthesis
8:25-8:45
Telescope Activity
8:45-8:50
Final Synthesis
Preparing your Poster
• In your Lab Manual, under Investigation:
– Answer Question 3 using the claim, evidence,
and reasoning formulation from page 1
– Use the answer to question 3 to help guide you
in making your poster. Add any drawings,
diagrams, etc. that you think are useful.
Activity Timeline
6:00-6:10
Introduction
6:10-6:25
Demos involving Lenses and Starters
6:25-6:40
Discussion of Vocab and Generate Questions
6:40-6:45
Choose question to investigate and form groups (2-3 people)
6:45-7:30
Focused Investigation
7:30-7:45
Make a poster to summarize your findings
7:45-8:15
Sharing out: each group will have 2 minutes to present
8:15-8:25
Converging Lenses Synthesis
8:25-8:45
Telescope Activity
8:45-8:50
Final Synthesis
Activity Timeline
6:00-6:10
Introduction
6:10-6:25
Demos involving Lenses and Starters
6:25-6:40
Discussion of Vocab and Generate Questions
6:40-6:45
Choose question to investigate and form groups (2-3 people)
6:45-7:30
Focused Investigation
7:30-7:45
Make a poster to summarize your findings
7:45-8:15
Sharing out: each group will have 2 minutes to present
8:15-8:25
Converging Lenses Synthesis
8:25-8:45
Telescope Activity
8:45-8:50
Final Synthesis
Light Travels in Straight Lines
• But… it can change directions when moving
from one medium to another
air
air
glass
• Index of refraction (n): a property of the
medium (glass/liquid/etc) that determines
how fast light can travel through it
• The larger the change in speed, the more the
light is bent - Snell’s Law
Image Brightness
LARGER the lens the BRIGHTER the
• The
image
• The shape of the aperture doesn't matter,
just the amount of light that gets through
Focal Point
• The curvature of the lens bends light toward a
special focal point which is different for different
lenses
• Higher curvature means more bending means
shorter focal length- a flat lens will not bend light
at all
air
air
glass
air
air
air
air
glass
glass
Focal length
Focal length
Image Inversion
• Simple parallel light rays get inverted beyond the
focal point
air
air
glass
Focal length
• For an extended object the same effect occurs
Focal length
Object and Image Distances
• Combined with the focal length of the lens,
these distances can be predicted using the
lensmaker's equation
1
1
1


image distance object distance focal length
Image distance
Object distance
Focal length
Object and Image Distances
• If the object is at infinity, the image is located at
the focal length of the lens
1
1
1


image distance object distance focal length
• This principle is important for telescopes, which
are used to observe objects that are located a huge
distance away
Putting Two Lenses Together
• These make up a simple telescope
• Separation: sum of the two focal lengths
Focal Length 1
Focal Length 2
Activity Timeline
6:00-6:10
Introduction
6:10-6:25
Demos involving Lenses and Starters
6:25-6:40
Discussion of Vocab and Generate Questions
6:40-6:45
Choose question to investigate and form groups (2-3 people)
6:45-7:30
Focused Investigation
7:30-7:45
Make a poster to summarize your findings
7:45-8:15
Sharing out: each group will have 2 minutes to present
8:15-8:25
Converging Lenses Synthesis
8:25-8:45
Telescope Activity
8:45-8:50
Final Synthesis
Telescope Activity
• Have your group select an
objective lens up front
• Find an appropriately sized
eyepiece and telescope tube
• On the Telescope Worksheet:
– Answer questions 1 - 4
QuickTime™ and a
decompressor
are needed to see this picture.
Telescope Activity – Compare with
Another Group
• Find a group who used a different
objective lens. Compare the two
telescopes you built.
• On the Telescope Worksheet:
– Answer questions 5 - 7
Activity Timeline
6:00-6:10
Introduction
6:10-6:25
Demos involving Lenses and Starters
6:25-6:40
Discussion of Vocab and Generate Questions
6:40-6:45
Choose question to investigate and form groups (2-3 people)
6:45-7:30
Focused Investigation
7:30-7:45
Make a poster to summarize your findings
7:45-8:15
Sharing out: each group will have 2 minutes to present
8:15-8:25
Converging Lenses Synthesis
8:25-8:45
Telescope Activity
8:45-8:50
Final Synthesis
Telescope Layout
• The properties of your telescope depended on
which lens you picked to as your objective
• For example, bigger lenses gather more light, but
result in more unwieldy telescopes
State-of-the Art Famous
Telescopes
Trade-offs
The Hubble Space Telescope
Keck: 10m Reflecting Telescopes
• Both Reflecting Telescopes (Mirrors)
• Hubble has a 2.4m Primary, but is in Space
• Each of Keck’s 10m primary mirrors is composed of 36 hexagonal
segments that work together as a single piece of reflective glass.
Refracting Telescopes - Comparison
36 inch Refractor at Lick
Observatory
Focal length 57 ft
4 ft diameter, > 25,000 lbs
More light gathering power
20 inch Refractor at Chabot
Space and Science Center
Focal length 28 ft
Smaller, cheaper to build
Bigger Telescopes
• Astronomers are constantly trying to
build bigger telescopes
– See more detail in known objects and find new
fainter objects
– But bigger telescopes need bigger mounts and
are more expensive
• One reason most modern telescopes are
reflecting (using mirrors) is that they can be
shorter than refracting telescopes
Challenger Telescope at
Fremont Peak Observatory
•
•
•
•
30” Diameter
144” focal length
Reflecting telescope
First light in 1986
Activity Timeline
2:00-2:10
Introduction
2:10-2:25
Demos involving Lenses and Starters
2:25-2:40
Discussion of Vocab and Generate Questions
2:40-2:45
Choose question to investigate and form groups (2-3 people)
2:45-3:30
Focused Investigation
3:30-3:45
Make a poster to summarize your findings
3:45-4:15
Sharing out: each group will have 2 minutes to present
4:15-4:25
Converging Lenses Synthesis
4:25-4:45
Telescope Activity
4:45-4:50
Final Synthesis
Activity Timeline
2:00-2:10
Introduction
2:10-2:25
Demos involving Lenses and Starters
2:25-2:40
Discussion of Vocab and Generate Questions
2:40-2:45
Choose question to investigate and form groups (2-3 people)
2:45-3:30
Focused Investigation
3:30-3:45
Make a poster to summarize your findings
3:45-4:15
Sharing out: each group will have 2 minutes to present
4:15-4:25
Converging Lenses Synthesis
4:25-4:45
Telescope Activity
4:45-4:50
Final Synthesis
Activity Timeline
2:00-2:10
Introduction
2:10-2:25
Demos involving Lenses and Starters
2:25-2:40
Discussion of Vocab and Generate Questions
2:40-2:45
Choose question to investigate and form groups (2-3 people)
2:45-3:30
Focused Investigation
3:30-3:45
Make a poster to summarize your findings
3:45-4:15
Sharing out: each group will have 2 minutes to present
4:15-4:25
Converging Lenses Synthesis
4:25-4:45
Telescope Activity
4:45-4:50
Final Synthesis
Activity Timeline
2:00-2:10
Introduction
2:10-2:25
Demos involving Lenses and Starters
2:25-2:40
Discussion of Vocab and Generate Questions
2:40-2:45
Choose question to investigate and form groups (2-3 people)
2:45-3:30
Focused Investigation
3:30-3:45
Make a poster to summarize your findings
3:45-4:15
Sharing out: each group will have 2 minutes to present
4:15-4:25
Converging Lenses Synthesis
4:25-4:45
Telescope Activity
4:45-4:50
Final Synthesis
Activity Timeline
2:00-2:10
Introduction
2:10-2:25
Demos involving Lenses and Starters
2:25-2:40
Discussion of Vocab and Generate Questions
2:40-2:45
Choose question to investigate and form groups (2-3 people)
2:45-3:30
Focused Investigation
3:30-3:45
Make a poster to summarize your findings
3:45-4:15
Sharing out: each group will have 2 minutes to present
4:15-4:25
Converging Lenses Synthesis
4:25-4:45
Telescope Activity
4:45-4:50
Final Synthesis
Activity Timeline
2:00-2:10
Introduction
2:10-2:25
Demos involving Lenses and Starters
2:25-2:40
Discussion of Vocab and Generate Questions
2:40-2:45
Choose question to investigate and form groups (2-3 people)
2:45-3:30
Focused Investigation
3:30-3:45
Make a poster to summarize your findings
3:45-4:15
Sharing out: each group will have 2 minutes to present
4:15-4:25
Converging Lenses Synthesis
4:25-4:45
Telescope Activity
4:45-4:50
Final Synthesis
Activity Timeline
2:00-2:10
Introduction
2:10-2:25
Demos involving Lenses and Starters
2:25-2:40
Discussion of Vocab and Generate Questions
2:40-2:45
Choose question to investigate and form groups (2-3 people)
2:45-3:30
Focused Investigation
3:30-3:45
Make a poster to summarize your findings
3:45-4:15
Sharing out: each group will have 2 minutes to present
4:15-4:25
Converging Lenses Synthesis
4:25-4:45
Telescope Activity
4:45-4:50
Final Synthesis
Activity Timeline
2:00-2:10
Introduction
2:10-2:25
Demos involving Lenses and Starters
2:25-2:40
Discussion of Vocab and Generate Questions
2:40-2:45
Choose question to investigate and form groups (2-3 people)
2:45-3:30
Focused Investigation
3:30-3:45
Make a poster to summarize your findings
3:45-4:15
Sharing out: each group will have 2 minutes to present
4:15-4:25
Converging Lenses Synthesis
4:25-4:45
Telescope Activity
4:45-4:50
Final Synthesis
Activity Timeline
2:00-2:10
Introduction
2:10-2:25
Demos involving Lenses and Starters
2:25-2:40
Discussion of Vocab and Generate Questions
2:40-2:45
Choose question to investigate and form groups (2-3 people)
2:45-3:30
Focused Investigation
3:30-3:45
Make a poster to summarize your findings
3:45-4:15
Sharing out: each group will have 2 minutes to present
4:15-4:25
Converging Lenses Synthesis
4:25-4:45
Telescope Activity
4:45-4:50
Final Synthesis
Activity Timeline
2:00-2:10
Introduction
2:10-2:25
Demos involving Lenses and Starters
2:25-2:40
Discussion of Vocab and Generate Questions
2:40-2:45
Choose question to investigate and form groups (2-3 people)
2:45-3:30
Focused Investigation
3:30-3:45
Make a poster to summarize your findings
3:45-4:15
Sharing out: each group will have 2 minutes to present
4:15-4:25
Converging Lenses Synthesis
4:25-4:45
Telescope Activity
4:45-4:50
Final Synthesis
Activity Timeline
3:00-3:10
Introduction
3:10-3:25
Demos involving Lenses and Starters
3:25-3:40
Discussion of Vocab and Generate Questions
3:40-3:45
Choose question to investigate and form groups (2-3 people)
3:45-4:30
Focused Investigation
4:30-4:45
Make a poster to summarize your findings
4:45-5:15
Sharing out: each group will have 2 minutes to present
5:15-5:25
Converging Lenses Synthesis
5:25-5:45
Telescope Activity
5:45-5:50
Final Synthesis
Activity Timeline
3:00-3:10
Introduction
3:10-3:25
Demos involving Lenses and Starters
3:25-3:40
Discussion of Vocab and Generate Questions
3:40-3:45
Choose question to investigate and form groups (2-3 people)
3:45-4:30
Focused Investigation
4:30-4:45
Make a poster to summarize your findings
4:45-5:15
Sharing out: each group will have 2 minutes to present
5:15-5:25
Converging Lenses Synthesis
5:25-5:45
Telescope Activity
5:45-5:50
Final Synthesis
Activity Timeline
3:00-3:10
Introduction
3:10-3:25
Demos involving Lenses and Starters
3:25-3:40
Discussion of Vocab and Generate Questions
3:40-3:45
Choose question to investigate and form groups (2-3 people)
3:45-4:30
Focused Investigation
4:30-4:45
Make a poster to summarize your findings
4:45-5:15
Sharing out: each group will have 2 minutes to present
5:15-5:25
Converging Lenses Synthesis
5:25-5:45
Telescope Activity
5:45-5:50
Final Synthesis
Activity Timeline
3:00-3:10
Introduction
3:10-3:25
Demos involving Lenses and Starters
3:25-3:40
Discussion of Vocab and Generate Questions
3:40-3:45
Choose question to investigate and form groups (2-3 people)
3:45-4:30
Focused Investigation
4:30-4:45
Make a poster to summarize your findings
4:45-5:15
Sharing out: each group will have 2 minutes to present
5:15-5:25
Converging Lenses Synthesis
5:25-5:45
Telescope Activity
5:45-5:50
Final Synthesis
Activity Timeline
3:00-3:10
Introduction
3:10-3:25
Demos involving Lenses and Starters
3:25-3:40
Discussion of Vocab and Generate Questions
3:40-3:45
Choose question to investigate and form groups (2-3 people)
3:45-4:30
Focused Investigation
4:30-4:45
Make a poster to summarize your findings
4:45-5:15
Sharing out: each group will have 2 minutes to present
5:15-5:25
Converging Lenses Synthesis
5:25-5:45
Telescope Activity
5:45-5:50
Final Synthesis
Activity Timeline
3:00-3:10
Introduction
3:10-3:25
Demos involving Lenses and Starters
3:25-3:40
Discussion of Vocab and Generate Questions
3:40-3:45
Choose question to investigate and form groups (2-3 people)
3:45-4:30
Focused Investigation
4:30-4:45
Make a poster to summarize your findings
4:45-5:15
Sharing out: each group will have 2 minutes to present
5:15-5:25
Converging Lenses Synthesis
5:25-5:45
Telescope Activity
5:45-5:50
Final Synthesis
Activity Timeline
3:00-3:10
Introduction
3:10-3:25
Demos involving Lenses and Starters
3:25-3:40
Discussion of Vocab and Generate Questions
3:40-3:45
Choose question to investigate and form groups (2-3 people)
3:45-4:30
Focused Investigation
4:30-4:45
Make a poster to summarize your findings
4:45-5:15
Sharing out: each group will have 2 minutes to present
5:15-5:25
Converging Lenses Synthesis
5:25-5:45
Telescope Activity
5:45-5:50
Final Synthesis
Activity Timeline
3:00-3:10
Introduction
3:10-3:25
Demos involving Lenses and Starters
3:25-3:40
Discussion of Vocab and Generate Questions
3:40-3:45
Choose question to investigate and form groups (2-3 people)
3:45-4:30
Focused Investigation
4:30-4:45
Make a poster to summarize your findings
4:45-5:15
Sharing out: each group will have 2 minutes to present
5:15-5:25
Converging Lenses Synthesis
5:25-5:45
Telescope Activity
5:45-5:50
Final Synthesis
Activity Timeline
3:00-3:10
Introduction
3:10-3:25
Demos involving Lenses and Starters
3:25-3:40
Discussion of Vocab and Generate Questions
3:40-3:45
Choose question to investigate and form groups (2-3 people)
3:45-4:30
Focused Investigation
4:30-4:45
Make a poster to summarize your findings
4:45-5:15
Sharing out: each group will have 2 minutes to present
5:15-5:25
Converging Lenses Synthesis
5:25-5:45
Telescope Activity
5:45-5:50
Final Synthesis
Activity Timeline
3:00-3:10
Introduction
3:10-3:25
Demos involving Lenses and Starters
3:25-3:40
Discussion of Vocab and Generate Questions
3:40-3:45
Choose question to investigate and form groups (2-3 people)
3:45-4:30
Focused Investigation
4:30-4:45
Make a poster to summarize your findings
4:45-5:15
Sharing out: each group will have 2 minutes to present
5:15-5:25
Converging Lenses Synthesis
5:25-5:45
Telescope Activity
5:45-5:50
Final Synthesis