Time required: One 60minute class period, with possibility to extend
You and a friend are sitting down to lunch, and all of a sudden...“AAACHOOOO!” One of you sneezes! Your first thought after “bless you” might be to wonder: “Did the cell phone, notebook, or peanut butter and jelly sandwich that I left on the table get covered in sneeze?”
If you’re curious about how far sneezes travel, you aren’t alone. Because sneezing can spread infectious diseases like the flu and the common cold, many scientists and doctors are interested in better understanding how far a sneeze can travel. For example, Dr. Lydia Bourouiba and Dr. John Bush of MIT’s Applied Mathematics Laboratory wrote mathematical equations to predict and describe the path of a sneeze. Their predictive equations, called mathematical models, incorporated a branch of physics called fluid dynamics (how fluids move) and accounted for gases as well as larger particles of spittle in three dimensions. The team then tested these predictions by actually filming and observing sneezes using a highspeed camera and computer imaging software. Grab a tissue and watch as they describe their findings in the Science Friday video “Nothing to Sneeze At”:Video Transcript Nothing To Sneeze At
Objectives: Students Will Be Able to:
 Collect and summarize data of the landing distribution of large droplets in a sneeze.
 Display data of sneeze droplet number and distance traveled in a histogram.
 Interpret graphic representations of sneeze droplet data to identify the riskiest distance for coming into contact with large sneeze droplets after a person has sneezed.
 Predict how behavioral changes, such as covering your mouth when you sneeze, might alter the distances that droplets travel.
Materials:
 Small 1 milliliter (1ml) plastic bulb dropper
 6 sheets of printer paper
 Sneeze stand: a stool, empty waste bin, or cardboard box, at least a foot tall
 Tape
 Washable, tempera paint in three colors, distributed in small paper cups
 Small paper cup of water
 Damp paper towel
 Pencil and metric ruler
 *Optional: place to dry painted papers
 *Optional: painting drop cloth
Experiment:
On a washable or protected flat surface, lay six pieces of paper in a line, long end to long end. At one end, set a box or overturned waste bin (“sneeze stand”). Label each piece of paper with a range that represents its distance from the sneeze stand, starting closest to the trash bin. For example, the first page will be labeled 021.5 centimeters (cm), the next 21.543 cm, etc. See an example below.
With a pencil, draw a circle around every sneeze droplet that is over 5 mm. Count the circled droplets on each page, and record those numbers on the sneeze droplet data table and analysis sheet. Now look at the smaller (<5 mm) droplets. What do you notice about where they fell? Record your observations in the notes section of your data table and analysis sheet.
3. Graphically answer: Where do most (large) sneeze droplets fall?
You will now make a histogram of the number of large droplets that fell on each piece of paper. Start by choosing a scale for the yaxis of your graph that encompasses the highest and lowest sneeze droplet number you recorded, and label the scale units. The xaxis is represented by the pieces of paper in this experiment, which make great “fixed intervals” for representing distance in your histogram. In each of the intervals on the histogram, draw a rectangle whose height matches the number of large droplets you recorded on the data sheet, using your yaxis labels as a guide. For example, if there were 3 large sneeze droplets on the first sheet of paper (021.5cm interval), you would draw a bar within the 021.5cm interval that goes up 3 units on the yaxis. You can work with the “sneeze histogram” on the data table and analysis sheet, or you can make your own. Here’s an example:
4. Conclude and evaluate: What patterns does your histogram show?
(these questions are also available on the data table and analysis sheet)
 Compare where you found large sneeze droplets to your observations of tiny sneeze droplets.
 Does it look like the tiny droplets (<5 mm) traveled as far as the larger ones?
 Based on your histogram, what is the distance away from a sneezer where you would least want to leave your notebook or sandwich?
 If you wanted to advise someone about the best place to leave their cell phone around a sneezing person, what would you tell them?
 How did the distribution of large sneeze droplets compare to your casual observations of tiny sneeze droplets? Describe what differences you would expect between the histogram you made and a histogram of tiny sneeze droplets and distance traveled. Would the total number of droplets be the same, higher, or lower? Which column would be the tallest?
 Did any sneeze droplets travel farther than the six pages or off the sides? How would you modify this experimental setup next time to improve your data collection?
 How do you think this simulated sneeze compares to real human sneezes? You may use both your own observations and the observations of Drs. Bourouiba and Bush from the video in your response.
 Once the pages have dried, line them back up as you did before, but this time divide each piece of paper in half. Relabel each half with a new range representing its distance from the sneezer, starting closest to the sneezer (for example, the first page will now have two ranges, 010.75 cm, and 10.7521.5 cm). Count the large droplets again, this time recording your data in a new data table. Make a new histogram, or modify your original one with new interval measurements on the xaxis. Does using shorter distance intervals in your histogram change your opinion about where most droplets fall?
 Advanced: Use a ruler to measure the size of every droplet over 2 mm and its distance from the dropper to create a “sneeze scatter plot,” with droplet size on the xaxis and droplet distance on the yaxis. Is there a pattern or correlation between droplet size and distance traveled? Do larger droplets travel farther?
 How does holding a tissue up to the dropper before a “sneeze” change the distribution of droplets? Use a different paint color and repeat the experiment, except hold a tissue in front of the dropper before simulating your sneeze. Compare histograms to see how using a tissue changes the distribution of large droplets.

What else can you describe with numbers?
Find out with these Science Friday articles:
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Taxi trips, fares, and routes – Hello, Stranger, Wanna Share a Cab?

CCSS.MATH.CONTENT.6.SP.B.4
Display numerical data in plots on a number line, including dot plots, histograms, and box plots. 
CCSS.MATH.CONTENT.6.SP.B.5
Summarize numerical data sets in relation to their context, such as by: 
CCSS.MATH.CONTENT.6.SP.B.5.A
Reporting the number of observations. 
CCSS.MATH.CONTENT.6.SP.B.5.B
Describing the nature of the attribute under investigation, including how it was measured and its units of measurement. 
CCSS.MATH.CONTENT.8.SP.A.1 (extension)
Construct and interpret scatter plots for bivariate measurement data to investigate patterns of association between two quantities. Describe patterns such as clustering, outliers, positive or negative association, linear association, and nonlinear association.
Discussion