Experiments
Gov't research grants on magnetism, guidance, sea turtles, magnetic highways and you tell us - if you find magnets in stars in space, sharks and birds following magnetic pathways, magnetic particles on mars then how can magnets not play a role in our lives?? Basically we just do not understand the effects of magnets on us - we live on the biggest magnet - at least that we can touch - the Earth.. The more you put all of this info in one place the more you see a much bigger picture of magnets and magnetism and how it really might be a part of everything we touch and see as some have postulated
Award Abstract #0344387
Geomagnetic Guidance Mechanisms in Sea Turtles

| NSF Org: | IOS |
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| Initial Amendment Date: | February 26, 2004 |
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| Latest Amendment Date: | April 13, 2006 |
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| Award Number: | 0344387 |
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| Award Instrument: | Continuing grant |
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| Program Manager: | Michael D. Beecher IOS Division of Integrative Organismal Systems BIO Directorate for Biological Sciences
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| Start Date: | March 1, 2004 |
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| Expires: | February 29, 2008 (Estimated) |
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| Awarded Amount to Date: | $413000 |
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| Investigator(s): | Kenneth Lohmann KLohmann@email.unc.edu(Principal Investigator) Catherine Lohmann (Co-Principal Investigator) |
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| Sponsor: | University of North Carolina at Chapel Hill 104 AIRPORT DR STE 2200 CHAPEL HILL, NC 27599 919/966-3411
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| NSF Program(s): | IBN ANIMAL BEHAVIOR |
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| Field Application(s): | 0000099 Other Applications NEC |
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| Program Reference Code(s): | OTHR,0000 |
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| Program Element Code(s): | 1160 |
ABSTRACT

GEOMAGNETIC GUIDANCE MECHANISMS IN SEA TURTLES
PI: Kenneth J. Lohmann
Co-PI: Catherine M. F. Lohmann
The long-distance migrations of sea turtles involve some of the most extraordinary feats of orientation and navigation in the animal kingdom. Hatchling turtles entering the ocean for the first time immediately establish courses toward the open sea and steadfastly maintain them long after swimming beyond sight of land. As the turtles mature, they often follow complex migratory pathways across vast distances that sometimes span entire ocean basins. Older turtles take up residence in feeding grounds but periodically migrate long distances to particular mating and nesting sites, after which many navigate back to the same feeding sites that they inhabited previously. How sea turtles guide themselves across vast expanses of seemingly featureless ocean has remained an enduring mystery of animal behavior.
Although sea turtles, like other animals, exploit multiple cues in orientation and navigation, growing evidence suggests that the Earth's magnetic field provides turtles with an important source of both directional and positional information that can be used in different ways at different life history stages. As hatchlings, turtles may first use the Earth's field as a directional cue that enables them to maintain headings as they migrate out to sea. Later, in the open ocean, regional magnetic fields apparently function as navigational markers that elicit changes in swimming direction at crucial geographic boundaries, thus helping young turtles remain within favorable oceanic regions and progress along the migratory route. Turtles at this life history stage, however, do not navigate to specific geographic locations. In contrast, older juveniles take up residence in coastal feeding grounds, and recent evidence suggests that they acquire a "magnetic map" that enables them to navigate to specific feeding sites. A similar navigational ability may explain how adult turtles locate nesting beaches......More.. More ... More...http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=0344387
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PARALLEL CIRCUIT
Background
Light bulbs are in parallel if they are side-by-side. They still share the electrical energy but they affect each other differently than if they were in series.
Materials Needed
2 batteries in holders
1 breadboard
2 light bulbs
4 wires with washers
push pins
Procedure
1. Connect up the simple circuit with 2 batteries.
2. Now replace the single light bulb by two in parallel as shown.

3. Remove one bulb from its socket. What happens? Why?
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4. How does the operation of this parallel circuit compare to the series circuit you worked with earlier?
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Background
Here's an example of how electricity and magnetism are closely related.
Materials Needed
1 three foot long wire
1 nail
2 batteries in holders
1 breadboard
paper clips
push pins
Procedure
1. Wrap the wire tightly around the whole length of the nail. Wrap all of the wire but about 6 inches at each end.
2. Try to pick up the paper clips by touching them with the nail. What happens?
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3. Hook up the batteries so that electricity is running through the wire.

4. Try again to pick up the paper clips. What happens? Why?
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5. Now disconnect the battery and try the paper clips again. Does the same thing happen as in step 2? What has happened to the nail?
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SIGNALING
Background
Signaling is a way to communicate where speaking won't work. Smoke signals, football signals and telemetry signals to spaceships are some examples. Signaling is also used to move information around inside of circuits.
Materials Needed
1 battery in holder 1 breadboard 1 light bulb 2 three foot wires push pins | | 1 toothpick 1 rubber band 2 1-foot wires with washer at one end 1 book |
Build A Switch
First you have to make a "momentary" switch. Here's how:
1. Take a wire that has no washer on one end and tightly wrap the bare wire around the end of one craft stick. The wires should be touching each other. Use the other wire for the other craft stick.

2. Put the 2 sticks on top of each other with the wires touching. Wrap a rubber band tightly around the other end.
3. Put the toothpick between the craft sticks near the rubber band. The wires should now touch when you push down on the switch and open up when you stop pushing.
4. Now that you have your switch, go on to the next page to finish this experiment. You will need to work with another team.
Procedure
1. Build the simple switched circuit using long wires so that your light can be placed a long way from the battery on the other team's breadboard. Keep your switch close to your battery.

2. Put a book upright between the two breadboards so that you cannot see the light and switch the other team.
3. Write a one word question and translate it into Morse Code.
4. Use Morse Code to ask the other team your question. Turn your light on for a "long" time for a dash and a "short" time for a dot. Use an extra-long flash of light to indicate that you are done.
5. Now decode their answer. Write down the dots and dashes. Then translate them into letters
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MAGNETIC FIELDS
Background
A magnetic field is the area around a magnet where its magnetic force can be felt.
Materials Needed
1 bar magnet
1 compass
Procedure
1. Place the magnet in the center of the next page.
2. Put the compass near one end of the magnet. Let the needle stop moving. Note the direction of the needle. Lift the compass and draw an arrow where the compass was. The arrow should point in the same direction as the painted end of the compass needle.

3. Move the compass toward the middle of the magnet. When the needle settles, note its direction and draw an arrow as before.
4. Repeat this as you move the compass to the other end of the magnet.
5. Now start again from a different place near the end of the magnet. Go from end to end at least 3 times. Explore both above and below the magnet.
6. When you're done, your arrows show you where the magnetic field is.
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Background
Switches provide an easy way to open and close an electrical circuit.
Materials Needed
2 batteries in holders
1 breadboard
1 paper clip
2 light bulbs
2 wires with washers
push pins
Procedure
1. Assemble the simple circuit with 2 batteries. Open and close the wires to turn the bulb off and on.
2. Now wire in the paper clip as a switch as shown and use it to turn the light on and off.
Question
Why does the light go out when you move the switch?
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Background
Let's see if there are magnetic insulators that are analogous to electrical insulators.
Materials Needed
1 round magnet
1 compass
notebook paper
brown paper
foil
cotton cloth
felt
plastic bag
Procedure
1. Earlier we tound that there are materials that act as electrical insulators that interrupt the flow of electricity. What did we use to determine whether the electrical current was interrupted?
2. Based on your first exploration of magnets, what are two ways we can determine if a magnetic force is present?
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3. Which of these methods do you think will be more likely to detect a weak magnetic force and why?
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4. For each of the materials, put one layer of the material between the magnet and the detector. Test tor the presence of a magnetic force in two ways. Record your observations in the following chart.

5. Repeat step 4 but put 4 layers of each material between the magnet and detector. Record your observations in the chart.
6. Repeat step 4 but put 16 layers of each material between the magnet and detector. Record your observations in the chart.
Conclusion
What can you conclude about magnetic insulators?
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Background
Light bulbs are said to be in series when they are in the same loop or circuit. All of the light bulbs share the available electrical energy equally.
Materials Needed
1 breadboard
2 batteries in holders
2 wires with washers
3 light bulbs
push pins
Procedure
1. Connect up the simple circuit with 2 batteries. Light the lamp.

2. Now replace the single light bulb by three in a row. Another way to say this is that the 3 lights are in series. What happens? Why?
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3. Remove one bulb from its socket. What happens? Why?
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Question
What do you think would happen if you connected 5 bulbs in series?
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Background
For electricity we found that there were positive and negative charges, that like charges repel each other and opposites attract. Let's see if there's an analogy for magnetism.
Materials Needed
1 compass
2 bar magnets
assorted magnets
2 round pens or pencils
Procedure
1. The bar magnets are marked with North and South poles. Put the pens under one of the bar magnets for rollers. Use the other bar magnet to determine if like poles attract or repel. Record your findings.
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2. Move all of the magnets away from one bar magnet. Put the compass at the end of the magnet marked "N". Draw an arrow on the diagram below showing what direction the painted end of the compass needle points. Then repeat for the end marked "S".

3. Use the compass in the same way to determine the location of the North and South poles for each of the other magnets. Draw a sketch of each one and show the poles.
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Background
Electricity is measured in units of volts, amps or watts. The higher the voltage, the more dangerous the electricity is.
Materials Needed
1 breadboard
2 batteries in holders
2 light bulbs
2 wires with washers
push pins
Procedure
1. Build the simple circuit with a single battery. Light the lamp.
2. Now replace the single battery by 2 batteries with both + signs in the same direction. What happens?
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3. Now reverse one of the batteries so that the two + signs are together. What happens? Why?
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4. What do you think would happen if you used 4 batteries to light one lamp?
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Try it with your neighbor.
Questions
Each D-Cell is 1.5 volts. How many volts do two D-Cells have?_______
What voltage is used in your house and school? _______
THE VOLTAGE IN YOUR HOUSE AND SCHOOL IS A LOT HIGHER THAN WE USE IN THESE EXPERIMENTS. NEVER TRY THESE THINGS USING ELECTRICITY FROM A WALL OUTLET!!
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Materials Needed
2 bar magnets
1 compass
Procedure
Investigate your magnet. Try different things and write down five observations that you make.
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CONDUCTORS AND INSULATORS
Background
One thing that makes electricity useful is that not all materials conduct electricity. Materials that do not conduct electricity are called insulators.
Materials Needed
1 battery in holder 1 breadboard 1 light bulb 2 wires with washers | | bag-o-stuff wires with clips push pins |
Procedure
1. Build the simple circuit shown in the schematic below. If you do it correctly, the bulb will light.
2. Replace one of the wires with the 2 wires with clips as shown below.

3. Complete the circuit by clipping each of the materials in the bag-o-stuff between the clips.
4. Figure out which materials are conductors and which are insulators. List the materials in the following chart and check the appropriate column. How will you be able to tell which are conductors and which are insulators?
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Question
How would you summarize what sort of materials are insulators and which are conductors?
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A SIMPLE COMPUTER
Background
Computers are made up of 1000's of simple circuits like this one.
Materials Needed
2 batteries in holders 1 breadboard 2 light bulbs | | 2 paper clips 6 wires with washers 4 labels | | push pins 2 washers |
Procedure
1. Look at the schematic below and try to predict how many lights will be lit when the switches are in different positions. Use the table below to record your predictions.
2. Build the switched, parallel circuit shown in the diagram. Label the switches as shown.
3. Use your circuit to complete the following table:
| | Number Of Bulbs Lit |
| First Switch | Second Switch | Predicted | Observed |
| 0 | 0 | | |
| 0 | 1 | | |
| 1 | 0 | | |
| 1 | 1 | | |
4. What type of calculation is your circuit performing?
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SIMPLE CIRCUIT
Background
Unlike static electricity that can exist on a single object, electrical current flows between objects.
Materials Needed
1 bread board 2 wires with washers 1 piece of string 1 battery in holder 1 light bulb push pins
Procedure
1. Figure out how to make the light bulb light.
2. Once you figure it out, draw a "schematic" of your circuit on the next page. This sort of picture is used to describe how to build a particular circuit. It uses symbols to represent things like the battery and light bulb. It shows what each wire connects together. Here are some of the symbols you can use for your schematic:
3. Once you have drawn your schematic, see how many different ways you can get the bulb to light. Draw a schematic for each one. What things are necessary in your circuit for the bulb to light?
4. Build the circuit shown here and make sure the bulb lights. Take out one of the wires. What happens? Why?
5. Build the circuit shown here and make sure the bulb lights. Replace the wire by the string. What happens?
Question
The string is an insulator and the wire a conductor. How might you define these terms?
An insulator is
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A conductor is
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LIGHTNING ROD
Background
It too much electrical energy flows through objects they can overheat and cause fires. Since electrical current prefers the path of least resistance, we can easily protect our homes from the energy in lightning.
Materials Needed
2 batteries in holders 1 breadboard 2 light bulbs | | 3 wires with washers 1 paper clip push pins | | paper pencil tape |
Procedure
1. Cut a lightning bolt out of paper.
2. Build the simple circuit with 2 light bulbs in series. Tape one bulb on the paper lightning bolt. When this light is lit it will indicate that lightning is striking.

3. Make a house out of paper. Houses tend to be made of wood, bricks, etc. Are these things good conductors?
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4. Put the other light bulb on the house. When this light is lit it will indicate that the house has been damaged by lightning.
5. Simulate lightning striking the house by briefly closing the switch.
6. Now protect the house by building a circuit parallel to the light. This circuit must have resistance that is lower than the house so use just a plain wire.

7. Make lightning strike again by closing the switch. What happens? Why?
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BUILD A BATTERY HOLDER
Background
Our first step will be to build battery holders that will allow us to connect up the batteries easily. Each team should make two holders.
Materials Needed For 1 Holder
1 D Cell battery 1 Toilet paper tube 2 nails Tape | | 2 Thick rubber bands 2 Pieces of foil 2 1-foot long wires with washers Long strips of newspaper |
Procedure
1. Wrap a stack of newpaper strips around the battery until it fits snugly in the paper tube. You may need some tape to hold the paper in place. BE CERTAIN THAT THE PAPER DOES NOT GO PAST THE ENDS OF THE BATTERY.
2. Put the wrapped battery into the center of the tube.
3. Mark the tube clearly with + and -signs to match those on the battery.

4. Gently crumple a piece of foil and put it in the tube on top of the battery.
5. CAREFULLY push a nail through the tube as close as possible to the foil. Use a pencil point if necessary to make holes.
6. Turn the tube upside down and repeat steps 4 and 5. Both nails should stick out of the sides of the tube in the same direction.
7. Put a rubber band over the 2 nails on each side. These rubber bands should be tight enough to pull the nails toward each other.

8. Attach one wire to each nail by wrapping the bare wire end tightly around the nail.
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RESISTANCE
Background
Resistors pass some electrical energy but convert some ot it to heat. They are neither conductors nor insulators but somewhere in between.
Materials Needed
2 batteries in holders 1 breadboard 4 wires with washers | | 2 light bulbs push pins | | 2 10-Ohm resistors 1 100-Ohm resistor |
Procedure
1. Build a simple parallel circuit. Both light bulbs should be lit equally.
2. Break the circuit to one of the lights and reconnect it with a resistor in the path. The resistance of an object is measured in Ohms. The higher the resistance, the more Ohms the object has. Resistors typically have the number ot Ohms marked on them. Start by using the 10 Ohm resistor.

3. With the resistor in the circuit, observe and record what changes have occurred in the two lights.
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4. Replace the resistor by the 100 Ohm resistbr. What happens?
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5. What do you think would happen if you put a 10 Ohm resistor in BOTH paths?
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Try it. What happens?
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Question
You have now learned about 3 types of electrical materials. What are they?
1. _________________________
2. _________________________
3. _________________________
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STATIC ELECTRICITY
Background
Invisible electrical charge can build up on objects that rub together. Sometimes this happens to clouds. The discharge can go unnoticed or be spectacular like lightning.
Materials Needed
2 plastic stick pens
1 ruler
1 piece of wool
12" of string tape
Procedure
1. Pull two desks apart and put the ruler between them. Tie the string around the middle of one pen and tape it in place. Use the string to hang this pen from the middle of the ruler. The pen should not be touching either desk.

2. For the rest of this experiment if you are asked to charge a pen, hold it by its cap and rub it briskly 50 times with the piece of wool. If you are asked to discharge a pen, roll it gently between your hands a few times.
3. Discharge both pens. Hold the loose pen by the cap and slowly bring it near the other pen. Observe what happens and record this in the chart on the next page.
4. Now charge the loose pen. Hold it by the cap and slowly bring it near the other pen. Observe what happens and record this in the chart below.

5. Discharge the loose pen. Now record what happens when you bring it near the other pen?
6. Charge both pens. Record what happens when you bring them near each other.
7. Discharge the loose pen but leave the hanging pen charged. Record what happens when you bring them near each other.
Conclusion
If two objects are charged the same, they _____________________ each other. If they are charged differently, they _____________________ each other.
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