Physics+Exploratorium

Ryan Listrotoc

Choose topic… on 4/19/12
 * Topic:** Optics/ Reflection

Recruit assistants, if desired… by 5/12/12
 * Assistants:** Maddy Weinfeld and Jessica Smith

=Proposal= Set up and Background research: plan/proposal/research.. 5/21/12
 * Demo 1/2:** "Look into Infinity"/ Periscope

Materials: 2 plane mirrors, object

-start by using one mirror to show how a mirror works; reflection of light -use two mirrors to show the infinite reflection of light

Website: []

Materials: Concave mirror -show properties of concave mirrors
 * Demo 3:** Concave Mirror/ "Mirage Maker"

Website: []


 * Demo 3.5:** Convex Mirror

Materials: Convex mirror

-show properties of convex mirrors

-Mini Look into Infinity
 * Demo 4** (Take away)

Materials: cardboard tubes, small mirrors

This schedule, which you just posted on 5/15 is unrealistic. It doesn't reflect the dates that we now have for the dress rehearsals 5/31 and 6/4. You have to push everything up.

Gather materials… 5/21/12 First attempt of demo #1-4… 5/23/12

=1st Draft Script= First draft written script… 5/27/12

1. Look into Infinity -introduce the idea of reflection -show plane mirror to audience and allow them to observe these characteristics that were just discussed -set up infinity demo by placing two plane mirrors parallel to each other; place an object between them -allow audience to see what happens in the demo...ask them what they see
 * Without light, there wouldn’t be sight. We are able to see because light from an object can move through space and reach our eyes.
 * Directing our sight in a specific direction is called the line of sight
 * In order to view an object, you must sight along a line at that object; and when you do, light will come from that object to your eye along the line of sight
 * Although this light diverges from the object in a variety of directions, your eye only sees the very small diverging cone of rays that is coming towards it
 * The light ray that reflects off of the mirror and travels to our eye is the reflected ray
 * The distance from the mirror to the object (object distance) is equal to the distance from the mirror to the image (image distance)
 * In this light-ray diagram, the solid lines show the actual path of the light rays; the dashed lines show the path of the light rays projected by your brain. You see images where the dashed lines come together.
 * This light-ray diagram shows the rays that come from the front of an object and those that come from the back. After the first reflection, you see one image in each mirror where the dashed lines come together (1). After the second reflection, you see a second image in each mirror (2), and so on.
 * As you look at the images formed in one of the mirrors on the diagram, notice that there is an alternation of front and back views, that the images appear to be grouped in pairs, and that a front side is always facing a front side and a back side is always facing a back side. This corresponds to what you actually observe in the mirrors.

2. Touch the spring -introduce mirrors of different shapes....concave mirrors appear to "cave" in, while convex mirrors are rounded outward -show the audience a concave mirror and ask them what they see -explain why there is a difference between what they see in this mirror and what they saw in the other mirror -set up spring demo -allow members from the audience to attempt to touch the image they see in the mirror -explain what just occurred > >.
 * the light from our bodies reach the mirror just like the last one
 * since the shape of the mirror is rounded, the light that is reflected will converge to a single point
 * The image you see is formed by the concave spherical mirror. Light rays spreading out from one point on the lightbulb are reflected by the concave mirror so that they come back together at a point in space - creating a real image of that point.
 * The rays continue on through this convergence point and strike your eye. The lens of your eye brings the rays together once again to create an image on your retina. Your eye and brain can't tell the difference between a retinal image of the reflected bulb and a retinal image of the actual bulb.
 * In some respects, however, the reflected image of the lightbulb differs from the actual bulb. Placing an object behind the reflected image will obscure the lightbulb. Many people feel queasy when they see this seemingly unnatural occurrence[[image:http://www.exploratorium.edu/snacks/touch_the_spring/touch_spring_3_224x200.gif width="224" height="200" align="left"]]

3. Convex Mirror -introduce another shape of a mirror...convex -this mirror is similar to the last one you just saw. it is rounded, so the image you will see will appear to be different from what you would normally see in an everyday mirror in your bathroom. unlike the last mirror, however, this mirror is curved outward instead of inward. this will result in a much different image -show the audience the mirror and allow them to see their image in it; ask them what they see -explain why there image appears like that
 * since the mirror is curved outward, the light that hits the mirror will reflect in a diverging manor
 * show the audience how the light will hit the mirror and reflect (this can be done with a light source, which will show why their image appeared blurry, etc)

4. Take-Away -now that we learned all the main concepts of mirrors, we can now use those concepts to create something -begin construction of mini look into infinity

=1st Draft Trifold= Trifold poster plan/sketch/draft 1… 5/27/12 Written list of needed materials… 5/27/12 -2 plane mirrors -convex and concave mirrors -set-up with lightbulb in box (for touch the spring demo) -cardboard tubes (for telescope in take-away demo) -2"x2" square mirrors (for take-away demo) -light source (laser)

Gather all needed materials… 5/29/12

=2nd Draft Script= Second draft written script… 5/29/12 Welcome to Reflection. I’m Ryan, and this is Jessica and Maddy. So, do you any of you know what reflection is or what it deals with?

//Let audience answer.//

Reflection deals with light and our viewpoint of it through mirrors. Without light, there wouldn’t be sight. We are able to see because light from an object can move through space and reach our eyes. Directing our sight in a specific direction is called the line of sight. In order to view an object, you must sight along a line at that object. When you do, light will come from that object to your eye along the line of sight. This concept is very important in reflection. In order to see a reflection in a mirror, our sight plays an important role. Although the light reflects from a mirror in a variety of directions, your eye only sees the very small amount of rays that is coming towards your eye.

Let’s take a look at our first mirror– the plane mirror. //(Let audience see themselves in mirror.)// What do you guys see?

//Let audience answer what they see.//

You should see an exact reflection of yourself. The mirror shows an image that is the same exact size and distance from the mirror as the object is.

Okay, now let’s see what happens when we place two mirrors opposite from each other. //(Begin “Look into Infinity” Demo/ Let audience see the infinite reflections)//

As you can see, it seems as though the reflection between these two mirrors continues forever. (Point to picture on poster) This picture shows a representation of what we see in these mirrors. As seen here, the light reflects from one mirror to another, and continues forever.

I feel like you are missing a few MAJOR concepts:(1) the law of reflection, (2) description of images, especially location, magnification and orientation. I wouldn't bother with type. You can probably use some or all of these demos, but you need to get into the PHYSICS. You are only dealing with WHAT is happening, not WHY. If you need help, come see me or email me.

(Take out periscope and allow audience to look through eyepiece) This device is called a periscope. It is similar to what we just saw in the 2 mirrors. Because the 2 mirrors in this device are placed in a specific spot, you are able to see light be reflected from one mirror to the other. This piece of equipment is often used in the real world by submarines.

//(Take out concave and convex mirrors)// Now we are going to look at mirrors that are different shapes. (Allow audience to look into mirrors) What are some differences you see in these mirrors?

//Let audience answer question.//

Do you guys know why this happened?

//Let audience answer question.//

As you can see, both of these mirrors are curved. //(Show concave mirror)// This is called a concave mirror due to the way it “caves” inward. When you look into this mirror, depending on how close you are to it, you can see many different things. If you stand very close to it, you will see a larger image of yourself. However, if you stand further away from it, your image will be flipped upside down and you will see a smaller image of yourself. This happens because of your position relative to the focal point. This is different for each and every mirror because mirrors have different sized curves. If you stand directly at this point, your image will disappear.

//(Show convex mirror)// This last mirror is known as a convex mirror because of its outward curved shaped. As you guys saw before, your image was different from the first mirror you saw. In this mirror, your image will always be upright, no matter how close or far you are from the mirror. The last characteristic of this mirror is that you will always see an image that is smaller.

//(Get out disc with coin inside/ Allow audience to see it)// What do you guys see?

//Let audience answer.//

In this demo, you guys are seeing a mirage of this quarter //(hold up quarter)//. There are mirrors covering this entire inside portion of this device. You are seeing an image formed by two concave mirrors facing one another. The object is placed at the center of the bottom mirror. Light from the coin reflects to the top mirror. This light continues to reflect from the top mirror to the bottom mirror. Because of the coin’s position, these reflections all meet at the hole on top of this device.


 * Maddy and Jess:** //(Begin take-away demo)// So now that we learned all these concepts of reflection, now we can create something out of mirrors for you guys to take home today. Do you guys remember the demo we did with the 2 plane mirrors that allowed us to see light be reflected into infinity?

Well, now we are going to make a mini version of that. //(Hand out materials)// In order to make this, all you need to do is place a mirror into each slit into the curved side of the cardboard tube. Once you do this, you can hold look into one mirror and see light be infinitely reflected.

=2nd Draft Trifold= Trifold poster draft 2 … 5/29/12

Practice 2 demos # 1 – 4… 5/29/12

=Final Draft Trifold= Trifold poster final draft…6/1/12 DONE

Practice 3 demos # 1 – 4…6/1/12 Dress Rehearsal 1… 5/31/12 DONE

You accomplished a lot this week. Thank you for getting caught up.

=Final Draft Script= Final draft written script... 6/2/12 Welcome to Reflection. I’m Ryan, and this is Jessica and Maddy. So, do you any of you know what reflection is or what it deals with?

//Let audience answer.//

Reflection deals with light and our viewpoint of it through mirrors. Without light, there wouldn’t be sight. We are able to see because light from an object can move through space and reach our eyes. Directing our sight in a specific direction is called the line of sight. In order to view an object, you must sight along a line at that object. When you do, light will come from that object to your eye along the line of sight. This concept is very important in reflection. In order to see a reflection in a mirror, our sight plays an important role. Although the light reflects from a mirror in a variety of directions, your eye only sees the very small amount of rays that is coming towards your eye.

Let’s take a look at our first mirror– the plane mirror. (Let audience see themselves in mirror.) What do you guys see?

//Let audience answer what they see.//

You should see an exact reflection of yourself. The mirror shows an image that is the same exact size and distance from the mirror as the object is. If you were to look at this mirror at angle, however, you would see an image from what you saw before when you looked at it straight on. This occurs because of the Law of Reflection, which states that the angle at which we look at the mirror must equal the angle at which the light reflects from the mirror.

Okay, now let’s see what happens when we place two mirrors opposite from each other. (Begin “Look into Infinity” Demo/ Let audience see the infinite reflections)

As you can see, it seems as though the reflection between these two mirrors continues forever. (Point to picture on poster) This picture shows a representation of what we see in these mirrors. As seen here, the light reflects from one mirror to another, and continues forever.

(Take out periscope and allow audience to look through eyepiece) This device is called a periscope. It is similar to what we just saw in the 2 mirrors. Because the 2 mirrors in this device are placed in a specific spot, you are able to see light be reflected from one mirror to the other. This piece of equipment is often used in the real world by submarines.

(Take out concave and convex mirrors) Now we are going to look at mirrors that are different shapes. (Allow audience to look into mirrors) What are some differences you see in these mirrors?

//Let audience answer question.//

Do you guys know why this happened?

//Let audience answer question.//

As you can see, both of these mirrors are curved. (Show concave mirror) This is called a concave mirror due to the way it “caves” inward. When you look into this mirror, depending on how close you are to it, you can see many different things. If you stand very close to it, you will see a larger image of yourself. However, if you stand further away from it, your image will be flipped upside down and you will see a smaller image of yourself. This happens because of your position relative to the focal point. This is different for each and every mirror because mirrors have different sized curves. If you stand directly at this point, your image will disappear.

(Show convex mirror) This last mirror is known as a convex mirror because of its outward curved shaped. As you guys saw before, your image was different from the first mirror you saw. In this mirror, your image will always be upright, no matter how close or far you are from the mirror. The last characteristic of this mirror is that you will always see an image that is smaller.

(Get out disc with coin inside/ Allow audience to see it) What do you guys see?

//Let audience answer.//

In this demo, you guys are seeing a mirage of this quarter (hold up quarter). There are mirrors covering this entire inside portion of this device. You are seeing an image formed by two concave mirrors facing one another. The object is placed at the center of the bottom mirror. Light from the coin reflects to the top mirror. This light continues to reflect from the top mirror to the bottom mirror. Because of the coin’s position, these reflections all meet at the hole on top of this device.


 * Jess and Maddy:** (Begin take-away demo) So now that we learned all these concepts of reflection, now we can create something out of mirrors for you guys to take home today. Do you guys remember the demo we did with the 2 plane mirrors that allowed us to see light be reflected into infinity?

Well, now we are going to make a mini version of that. (Hand out materials) In order to make this, all you need to do is place a mirror into each slit into the curved side of the cardboard tube, facing each other. Once you do this, you can look into one mirror and see light be infinitely reflected.

Dress Rehearsal 2… 6/4/12 Show… TBA