LESSONS: Earth/Space
The majority of lesson ideas below require minimal resources other than the smartphone, and are relevant to introductory physics in high school and college. However, creative individuals are using smartphone science in more complex ways, with drones, engineering kits, and much more. Follow us on Twitter @PhysicsToolbox and see our Publications page for additional content.
Circumference of the Earth
What is the circumference of the Earth?
Try This
Use either equinox to your advantage to measure the circumference of the Earth using a method similar to that used by Eritosthenes! On the Equinox at astronomical noon, the sun is directly overhead at the equator (where the latitude is 0 degrees). At a point not on the equator, use the GPS to determine your latitude and the Inclinometer to determine the angle of the sun at astronomical noon at your location. Considering that the Earth makes up a full 360 degrees around, use the known difference in latitude from the equator, the known distance per latitude degree, and the difference in inclination of the Sun to determine the total distance around the Earth (approximated for the Earth as a perfect sphere).
Seismic Vibrations
What is the relationship between SEISMIC VIBRATION STRENGTH and DISTANCE from the "epicenter" of the shake?
Try This
Perform three different investigations from IRIS (Incorporated Research Institutes for Seismology). In these activities, use the Accelerometer tool along with a meter stick, tape, and chair or water bottle to simulate the relationship between an earthquake's magnitude and intensity. Calculate the energy released during a weight drop (magnitude) and use the accelerometer to investigate what happens to the energy as the source is moved further and further from the sensor (intensity). Examine USGS ShakeMaps to explore other factors besides event size and distance from the source to the receiver that affect the intensity (i.e. geologic structures and materials).
Challenge Yourself
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Create a graph of Intensity vs. Distance for a "seismic event," and derive a mathematical expression for this relationship.
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If there are any constants in this mathematical expression, explain their significance.
Related Resources
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Lesson Plan from IRIS. "How are Magnitude and Intensity Different?" [External website]
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Lesson Plan from IRIS. "Exploring Three-Component Seismic Data with Accelerometers." [External website]
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Lesson Plan from IRIS. "How Hard Does the Ground Shake During an Earthquake?" [External website]
Measuring Height and Vertical Speed with Air Pressure
What is the relationship between the PRESSURE and HEIGHT above ground?
Try This
Using the Barometer tool, determine the relationship between air pressure and height above ground. A meter stick can be employed to determine the height above ground (by measuring and counting the heights of stair steps, for example).
Related Resources
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Student worksheet from Vieyra Software Measuring Height with Pressure
Liquid Pressure and Stevin's Law
What is the relationship between PRESSURE and DEPTH below the surface of a liquid?
Try This
Using the Barometer tool, place the smartphone inside of a water-proof case and submerge it under a still container of water. Use a meter stick to measure the depth of the device below the surface. Determine the relationship between pressure and depth for water. Perform the same experiment with different fluids (soap, saturated salt water, oil, alcohol, etc.)
Challenge Yourself
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Create a graph of Pressure vs. Depth for water, and derive a mathematical expression for this relationship.
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Create additional graphs of Pressure vs. Depth for other fluids, and derive mathematical expressions for these relationships.
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If there are any constants in these mathematical expressions, explain their significance.
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Using prior understandings about fluid pressure, determine the density of each fluid studied.
Related Resources
Gas Laws in a Refrigerator
What is the relationship between the TEMPERATURE, PRESSURE, and RELATIVE HUMIDITY of a constant volume of air?
Try This
Place a smartphone inside of a sealed jar while recording data on the Barometer, Thermometer, and Hygrometer tools. Place the jar inside of a refrigerator or freezer for a few minutes. Analyze the data and describe the changes in all of the variables throughout the experiment.
Related Resources - Click the image to get a lesson plan!
Related Resources
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Student worksheet from Vieyra Software Gay Lussac's Law
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The Physics Teacher. "Kitchen Physics: Lessons in Fluid Pressure and Error Analysis."
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Alfonso d'Ambrosio. "Experimenti con Microbit et Scratch: il sensore di temperatura dal frigorifero all'asiugacapelli."
Ambient Noise
How loud is my environment?
Try This
Using the Sound Meter tool, measure the average intensity of ambient noise to determine the level of noise pollution that surrounds you. Record values in quiet and loud environments, and compare these values to charts online to determine if hearing damage might result in particular environments.
Challenge Yourself
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What is the quietest environment that you can possible find?
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What is the loudest environment that you found?
Related Resources
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Science on Stage iStage: "Noise Pollution." See pages 32-37.
Color by Reflection
What do PIGMENTED OBJECTS look like under monochromatic lights?
Try This
The color of light sources influences the way we perceive objects. For example, if the sun was truly only pure yellow, we would only see the world in shades of yellow! The fact that we can see objects of a full rainbow of colors suggests that the sun, is, indeed, producing the full visible spectrum of light.
Use the Color Generator tool to produce a single color of light, such as red. In a completely darkened room, shine the pure red screen down on a set of colored candies, Lego blocks, or beads (simple colors work best, such as red, blue, green, and yellow). Attempt to sort the items into similarly-colored groups. Then, turn on the ambient light and see how successful you were! Mix up the candies, and try again with pure blue and green, and then secondary colors of light (yellow, magenta, and cyan). Keep track of which colored candies are easiest to sort under which colors of light, and come up with a potential explanation for why this is the case.
Challenge Yourself
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Complete the student worksheet listed in "Resources" below.
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Attempt to predict the colors that a given color of candy will appear to your eye when observed under a specific color of light.
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Using a print-out of the South African flag, sketch what you expect the flag will look like under white, red, blue, green, yellow, magenta, and cyan light.
Related Resources
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Rebecca Vieyra. "M&M's Color Sorting Lab."
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Bree Barnett-Dreyfus: "Color Subtraction: Reflected Color"
UV Absorption
Do my sun glasses actually block out UV light?
Try This
Acquire one or more sets of sunglasses that are rated to block out UV light. Using the UV tool, determine compare the UV reading outside under the sky, versus the UV reading when covered by a single lens of the sunglasses. Determine what percentage of UV is blocked by the glasses. Using sunglasses without UV protection, determine if any UV is blocked at all.
Challenge Yourself
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Compare UV readings of the sky at various times throughout the day.
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Compare UV readings under clear or overcast sky when the sun is at the same height. Do clouds block UV light?
Seasons and Flux
What causes the seasons?
Try This
Use the Light Meter to model flux experienced at various points on the surface of the Earth. Prepare a globe with an equator, and hold at an angle with respect to a parallel sun or light source. Observe changes in the light intensity experienced by the smartphone, held tangent to the surface, in the north and south hemispheres.
Challenge Yourself
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For an earth and the light source both in a plane parallel to the "ground," plot the relationship between latitude and light intensity.
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Explain how this graph would look different if the globe was titled differently (i.e. if the equator was always parallel to the sun, or if the equator was vertical to the ground).
Related Resources
Albedo
How does light REFLECTION and ABSORPTION influence CLIMATE CHANGE?
Try This
Use the Light Meter tool to compare the reflectivity of various types of surfaces representative of different types of ground cover: snow, water, vegetation, sand, etc.
Challenge Yourself
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Predict which types of ground cover produce greater reflectivity.
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Consider how ground cover might change if the Earth were to heat up or cool down, and what effect this would have on albedo and environmental feedback loops.
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Using a more specialized app such as Albedo; A Reflectance App, and a gray card, perform more detailed analyses of specific reflectivities of red, blue, and green light.
Related Resources
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Alfonso D'Ambrosio: "Global Warming: A Poor Laboratory Activity on Albedo Using a Smartphone" (translate from Italian)
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Bree Barnett-Dreyfus: "Color Subtraction: Reflected Color"
Eclipses, Transits, and Exoplanet Detection
How do astronomers detect EXOPLANETS?
Try This
Using the Light Sensor tool, model the eclipsing of exoplanets in front of their stars. Use changes in light intensity, as observed from a distance, in order to determine the period of rotation of the exoplanet, its size, and its diameter.
Challenge Yourself
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How is this model similar to / different from the way astronomers actually identify exoplanets?
Related Resources
Earth's Magnetic Field
Which way does the EARTH's MAGNETIC FIELD point at my latitude and longitude?
Try This
Using the Magnetometer tool, determine the strength of the Earth's magnetic field in three dimensions. Using an understanding of vectors, determine the direction of the Earth's magnetic field.
Challenge Yourself
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Share magnetic field values with students across the globe, noting respective latitude and longitude values.
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Create a vector array of magnetic field values to observe the Earth's whole gravitational field.
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Collect data over time, and observe changes in the Earth's magnetic field due to solar activity.
Related Resources
Planetary Magnetism
What do magnetic fields look like around planets?
Try This
Using the Magna-AR setting that makes use of the magnetometer, accelerometer, and gyroscope, visualize the Earth's magnetic field and explore a model "Earth" and a model "Planet X."
Related Resources
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Teacher Guide: Planetary Magnetism Science
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Student Worksheet: Planetary Magnetism Science
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Digi Kit: Planetary Magnetism Science
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Learn more about the Magna-AR setting on our Project Page
Energy in Magnetic Fields and Solar Flares
Where does energy "go" when magnets and their fields interact?
Try This
Using the Magna-AR setting that makes use of the magnetometer, accelerometer, and gyroscope, visualize how fields change when magnetic poles are brought together. Read about the implications magnetic field energy has for how stars release energy into space.
Related Resources
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Teacher Guide: Energy in Magnetic Fields and Solar Flares
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Student Worksheet: Energy in Magnetic Fields and Solar Flares
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Learn more about the Magna-AR setting on our Project Page