Cell Phone Radiation - How close is too close? Preview Close Preview

Welcome to iLabs! (1/11)

Remote Online laboratories (iLabs) are lab instruments located at universities around the world that you can use through the Internet, allowing you to carry out different experiments from anywhere at any time.

Before we get started, we would really appreciate it if you would answer a few questions that will help us understand how we can better help students learn science.

Please click on this link: Click Here and answer the questions to the best of your ability.

Cell Phone Radiation (2/11)

Now let's get started with your lab! The following sections will be a part of the assignment your teacher is giving you, and might be for points that count towards your class grade.

Have you ever heard rumors that using your cell phone too much can hurt your brain? Is it possible that using your cell phone could cause damage to your body? Is there anything you can do to protect yourself from possible harm?

Let's take a look at this CBS news report on cell phones and human health:

That seems pretty alarming!

What does the Center for Disease Control and Prevention (CDC) have to say about cell phone use? See what they say about how cell phone radiation works, and if your health is at risk when you use a cell phone.Cell Phone Radiation FAQs

After reviewing the information from both CBS and the CDC, answer the following question(s). Use the space provided to type your responses.

How does a cell phone use radiation to function?

Does the scientific community agree that cell phones pose a risk to your health? How do you know?

If you were a scientist, how would you test if cell phones cause health risks? What type of experiment might you design to figure out if you are hurting yourself with your cell phone?

How is Radiation Measured? (3/11)

Radioactivity is typically measured by a Geiger counter. Different models of Geiger counters detect and measure different kinds of radiation.

GC

Geiger counters come in many forms, but they usually consists of three parts:

g

  1. Geiger tube – a gas-filled tube whose gas ionizes when charged particles or electromagnetic waves from a radioactive material pass through the gas. The ions create a signal that can be measured, allowing the Geiger counter to count the number of radioactive particles or electromagnetic waves that pass through the tube.

  2. Visual readout – a meter that keeps track of the number of radioactive particles or electromagnetic waves being detected by the Geiger counter.

  3. Audio readout – a meter that makes one “click” sound for each radioactive particle or electromagnetic wave counted by the Geiger counter. The clicks sound like this.

Let's Do an Experiment with Radiation (4/11)

The CBS News report seemed to say something very different from the Center for Disease Control and Prevention fact sheet, but both mention that moving your phone even a very short distance away from your body might be a good idea.

Why would that be the case?

To investigate this, you can design your own experiment to learn about how radiation moves through air. The instrument you will be using in this lab is located at the University of Queensland in Australia.

UQ

How does this lab work?

The lab equipment consists of:

  1. A Geiger counter
  2. A radioactive material (Strontium-90)
  3. A Circuit board that connects Geiger counter to the internet

set

The things that you can change in order to design an experiment are:

  1. The distances in millimeters from the strontium-90 source at which radiation can be measured. Radiation is measured in units of "particle counts", which means the number of particles emitted from the strontium-90 sample that were counted by the Geiger counter.
  2. The measurement time in seconds that each measurement of particle counts will last.
  3. The number of trials that will be conducted at the settings listed above.

What is strontium-90?

Research Question (5/11)

What are you trying to find out in this lab? What question are you trying to answer?

The last page gave you some information about the instrument you will be using to conduct an experiment about radiation. Now you need to develop the question you want to answer using this setup.

What is a research question? That is what your experiment is designed to answer. A “good” scientific research question is one that allows you to perform a test or experiment to show how your variables might be related. The results of the experiment will allow you to say something about how those variables are related. Your research question must be testable to make a strong statement about how the variables are related.

Your research question will guide your experimental design in the next step.

What is the independent variable in your remote labs experiment?

What is the dependent variable in your remote labs experiment?

Write your research question for your remote labs experiment.

Design Your Experiment (6/11)

Design your experiment by choosing values for the variables on the left. To learn more about each variable, click on the question mark icon next to the variable.

When you click "Run", the experiment will run on the instrument located at the University of Queensland in Australia.

Note that experiments are run one at a time, so you are being placed in a line or queue to run yours. If you don't want to wait, you can log out and come back later. Everything you have done up to now will be saved.

Radioactivity over Distance
Source
Absorber
Distance (mm)
Duration (s)
Trials
View your iLab Results (7/11)

Now let's take a look at the data you got from running your remote experiment.

You can review both your experimental design and the data you generated from your experiment in table form by clicking on the tabs below. Take a look at your data.

Do you notice any patterns in your data? If so, describe what those patterns are.

If you do not notice any patterns in your data, are there any changes you might make to your experimental design?

Analyzing your iLab Results (8/11)

Let's take a closer look at the results from your experiment.

By clicking on the tabs below, you can see the variables you chose for your experimental design, your data in table form, and a graph of your data.

Take a close look at the graph of your data in order to determine if there is a relationship between radiation (in particle counts) and distance. You can apply various best-fit functions to the graph in order to investigate the nature of this relationship, if there is one present.

Do you think a relationship exists between your two variables? What kind of relationship, and how do you know?

Is there an Equation to Describe the Relationship? (9/11)

Is there a way to describe the relationship between radiation intensity and distance mathematically? What is really happening here?

As the video mentions, light follows the inverse square law. Since all types of radiation travel the same way, just with different wavelengths, that means that all types of radiation follow the inverse square law. Here is another look at how this works with radiation in particular:

Write a mathematical equation to describe the relationship between radiation and distance.

Does your data exactly match what you would predict using the equation you developed? Why or why not?

What does this mean in terms of your cell phone? (10/11)

At the beginning of this activity, you watched a CBS news report and read a fact sheet from the Center for Disease Control and Prevention. While they disagree about whether or not cell phones should have warning labels, both mentioned that moving your cell phone even a short distance away from your body might be a way to protect yourself from harm caused by radiation.

Cell

Now that you have completed the Radioactivity iLab, and know a bit more about the relationship between radiation and distance, you can apply what you have learned to the following question(s):

Based on your experimental evidence, do you think that the recommendation to keep distance between your cell phone and your body makes sense? Why or why not?

Post-Survey (11/11)

Now that you have used iLabs to complete an assignment, we would like to again ask you some questions that will help us understand how we can better help students learn scientific concepts and how we can improve our product.

Please note, some of these survey questions are going to be very similar or even the same as questions we asked you before. We ask that you answer them honestly, as this will be a big help to us.

Please click on this link: Click Here and answer the questions to the best of your ability.