Microscopy+Box+--+Addie+and+Blair





Summer 2011 Fordham Project Making Microscopes

**Lesson 1** Materials: -convex magnifying lenses -Sheets of paper -Droppers -Cups of water (one per pair of students at station) -Laser pointer -Flashlight (maglight/led) -Cardboard tube -Small fish tank filled ¾ of the way with water -Powdered milk -Convex, concave lenses, mirror -microscope slide covers -microscope slide with divet

Engagement: -Students hold up a hand lens near a window and hold a piece of paper behind it -What happens and why? -What can you see? -What details do you observe? -What happens as you move the lens towards the paper? Towards the window? -How do you think the picture is formed?

Explore/Explain: Stations--see attached worksheets -Station 1: Magnification with water droplets -Station 2: How can you find the focal length of a lens? -Station 3: Exploring how lasers and lenses manipulate light.





**Lesson 2** Materials: -See lesson 1 -Exit slips

Engagement: demonstration with ray optics lenses--use a large lens and lasers on the whiteboard to demonstrate how lens in your eye focuses images on your cornea, what happens in nearsighted and farsightedness, and how these things can be corrected. The components for this are not included in our box but can be ordered at: []

If these lenses cannot be obtained, show youtube video demonstrating these concepts at: []

Explore/Explain: Stations (same as lesson 1)

**Lesson 3** Materials: -See lesson 1 -Exit slips

Engagement: discovery channel video--how high end optical lenses are made

http://www.youtube.com/watch?v=X7_wL0ZZi6k

Exploration: Stations (same as lesson 1)

Explanation: -Share out the key take aways -Discuss refraction (speed of light changes as it travels through different media) -Discuss why a convex lens makes can create an inverted image a set distance away -Discuss why a convex lens makes objects appear magnified

Extension: What could be the effect of combining more than one lens? Students write and share their predictions

Evaluation: Exit Slip/Reflection--What have you learned about light, lenses, and magnification over the past 3 days of stations?

**Lesson 4 (Over two periods)** Materials: -convex magnifying lenses (two per pair of students at a station) -meter sticks -calculators -hand loupe (optional) -clay -cardboard tubing

Engagement: Pick up two lenses--what happens to the magnification when you use two lenses on top of each other. Predict how much you can increase the magnification of the lenses.

Exploration: Students test out different ways of combining two lenses to magnify an object on a piece of paper. What happens when you move the lenses away from each other or closer to one another? What happens when you change the distance of the lenses from your eye or the object being magnified? Students are given the image below and asked to calculate how far apart they should space their lenses given the focal length they calculated in Station 2.

Explanation: -Discuss how two find the distance apart two lenses should be placed in order to magnify it

Extension: -Students find these distances and attempt to create a hand loupe

Evaluation: Students draw a diagram and turn in their calculations for the dimensions of the hand loupe.

**Lesson 5 (optional)** Materials: -compound microscope -diagram of a microscope

Engagement: What types of objects were you able to magnify with your loupe? What could have made your loupe more powerful?

Exploration: Students examine a compound microscope. What are all of the features and components and how do they work?

http://www.google.com/imgres?imgurl=http://cdn3.explainthatstuff.com/opticalmicroscope.gif&imgrefurl=http://www.explainthatstuff.com/microscopes.html&usg=__jxf9tkpF33xzr7_tSi5GK7NCVGs=&h=560&w=380&sz=16&hl=en&start=14&zoom=1&itbs=1&tbnid=RAh97ae0qaU29M:&tbnh=133&tbnw=90&prev=/search%3Fq%3Dsimple%2Bside%2Bview%2Binside%2Bcompound%2Bmicroscope%26hl%3Den%26client%3Dsafari%26rls%3Den-us%26tbm%3Disch&ei=Wzr5TbezBc21twfEmfHsDw__

__Explanation: Briefly show a diagram that shows a cutaway view of a microscope. How is this similar to our hand loupe? How is it different?__

__Extension: Students explore how the compound microscope uses special lenses to generate large magnifications.__

__Evaluation: Explain how lenses work to create magnification in a microscope.__

__ **Lesson 6** __ __Materials:__ __-convex magnifying lenses__ __-cups of water__ __-microscope slides (some with a divot well and some plain)__ __-droppers__ __-compound microscope__ __-runoff from bottle biome__ __-data table for students to take notes (optional)__

__Engagement: What do you think we will be able to see in your pond scum when you look at it up close under the microscope? Draw what you think you will see in the space below:__

__Exploration:__ __-Students make general observations of bottle runoff (color, clarity, can you see anything living with the naked eye?__ __-Students use different tools to examine runoff and collect data on what they see (pictures, notes, identification of different species)__ __-Students look under the microscope to examine their pond scum up close. They write and draw observations in their science notebooks.__

__Explanation:__ __-Which tool was most successful in viewing different living things (drop of water, magnifying lens, student-made loupe or microscope)?__ __-Discuss the parts of a microscope and why it is easier to focus__

__Extension: How could you build your own microscopes? Which parts would be hardest to get just right?__

__Evaluation:__

__Draw how light will pass through your sample of pond scum then through lenses in the microscope to create a large image of the microscopic organisms on your retina.__

__**-Station 1: Magnification with water droplets**__

__Materials:__ __Slide Cover__ __Cup of Water__ __Water dropper__ __Ruler__

__Investigation question: How much can you magnify using just water?__

__Directions:__ __1. Place the glass microscope slide over the letter T below:__

__T__

__2. Use your ruler to measure the height of the T and record the height on the data table.__

__3. Use the Water dropper to place on drop of water on top of the glass slide directly over the T. What do you notice?__

__4. Measure the height of the image of the T by holding the ruler just above the surface of the water. Record this height on the data table.__

__5. Continue to add drops, measure the height of the T, and record your data on the data table until your slide cover cannot hold any more drops.__

__6. The **magnification** of each image is a measure of how much bigger the image is than the original object (the printed T on the page). The magnification can be calculated by dividing the height of the image by the height of the object (height of the unmagnified T). The formula is:__

__Magnification = Himage/Hobject__

__7. Calculate the Magnification for each different number of water droplets you measured.__

__8. Make a graph of your data in the space below__

__|__ __|__ __|__ __|__ __|__ __|__ __|__ __|__ __|__ __|__ __|__ __|__ __|__

9. Answer the following questions:

What patterns do you notice in your data?

How do you think the image of the T gets magnified by the water?

Look through the side of your cup of water--are objects magnified through the side of the cup of water?

Are objects magnified through the water when you look from the top of the water?

How can you explain this difference?

What parameters are necessary in order to use water as a magnifier?


 * -Station 2: How can you find the focal length of a lens?** This station should be completed in a dark room.


 * Materials:**
 * Candle**
 * Meter Stick**
 * Convex Lens**
 * Clay**
 * Sheet of Paper**


 * Directions:**


 * 1. Set up the materials according to the diagram below:**


 * 2. Make sure that the candle is positioned at the 0 cm end of the meter stick. Hold the lens several centimeters from the candle. The distance from the candle (the "object") to the lens is called O. Measure O and record it in your data table.**


 * 3. Keeping the lens O cm from the candle, move the sheet of paper back and forth until you get a focused image of the candle on your paper.The distance from the lens to the paper (the "image") along the meter stick is called I. Measure I and record it on your data table.**


 * 4. Move the lens and record your new value for O.**


 * 5. Measure and record the new I value for this O.**


 * 6. Repeat steps 4 and 5 for two more lens positions.**


 * 7. Does I depend on O? How?**


 * 8. The relationship between O and I is characterized by the formula :**


 * 1/I +1/O=1/F**


 * in this formula, F refers to a number called the Focal Length of a lens. Different lenses have different focal lengths and this value is important to scientists to figure out in order to design magnification systems like projectors and microscopes. In the next part of this unit, we will learn to use the F value of your lens in order to calculate how far apart you should space two lenses to make a loupe magnifier.**


 * Use your data to calculate F for your lens. Show your work in the space below:**


 * How do you think the image of the candle is being created on the paper?**


 * What do you notice about this image?**

-Station 3: Exploring how lasers and lenses manipulate light. **This station should be completed in a dark room.**

Materials: Fish Tank Laser Pointer Water Powdered Milk Lenses Clay

Setup:

Fill the fish tank with at least 3 inches of water.

Add a small amount of powdered milk to make the water just slightly cloudy so that it catches the laser light.

Directions: 1. Shine the laser into the water, what do you observe? What direction does the beam shine?

2. Hold a lens in the water and shine a laser through different parts of it. Draw your observations of how the light beam travels through the lens on the diagram below:

3. Try shining the laser beam through other types of prisms and lenses. Draw diagrams of what happens in the space below.

What happens to light as it passes through lenses and prisms?

How do you think this is happening?


 * -Station 2: How can you find the focal length of a lens?** This station should be completed in a dark room.


 * Materials:**
 * Candle**
 * Meter Stick**
 * Convex Lens**
 * Clay**
 * Sheet of Paper**


 * Directions:**


 * 1. Set up the materials according to the diagram below:**


 * 2. Make sure that the candle is positioned at the 0 cm end of the meter stick. Hold the lens several centimeters from the candle. The distance from the candle (the "object") to the lens is called O. Measure O and record it in your data table.**


 * 3. Keeping the lens O cm from the candle, move the sheet of paper back and forth until you get a focused image of the candle on your paper.The distance from the lens to the paper (the "image") along the meter stick is called I. Measure I and record it on your data table.**


 * 4. Move the lens and record your new value for O.**


 * 5. Measure and record the new I value for this O.**


 * 6. Repeat steps 4 and 5 for two more lens positions.**


 * 7. Does I depend on O? How?**


 * 8. The relationship between O and I is characterized by the formula :**


 * 1/I +1/O=1/F**


 * in this formula, F refers to a number called the Focal Length of a lens. Different lenses have different focal lengths and this value is important to scientists to figure out in order to design magnification systems like projectors and microscopes. In the next part of this unit, we will learn to use the F value of your lens in order to calculate how far apart you should space two lenses to make a loupe magnifier.**


 * Use your data to calculate F for your lens. Show your work in the space below:**


 * How do you think the image of the candle is being created on the paper?**


 * What do you notice about this image?**

-Station 3: Exploring how lasers and lenses manipulate light. **This station should be completed in a dark room.**

Materials: Fish Tank Laser Pointer Water Powdered Milk Lenses Clay

Setup:

Fill the fish tank with at least 3 inches of water.

Add a small amount of powdered milk to make the water just slightly cloudy so that it catches the laser light.

Directions: 1. Shine the laser into the water, what do you observe? What direction does the beam shine?

2. Hold a lens in the water and shine a laser through different parts of it. Draw your observations of how the light beam travels through the lens on the diagram below:

3. Try shining the laser beam through other types of prisms and lenses. Draw diagrams of what happens in the space below.

What happens to light as it passes through lenses and prisms?

How do you think this is happening?