You and Zack Start Testing the Milk

"Wait," you say. "How will we know what the test results mean? We have nothing to compare them against."

"Oh, right," he says. "The control group thing. Well, how about this?" He holds up a carton of milk. "I'm pretty sure it's not contaminated, because I drank most of it a few hours ago."

"It'll have to do," you say.

"Okay, right," he says. "Evil Milk A, Good Milk B. First, the thermometer test." He grabs the milk bottle from you and compares the feel of it with the carton. "Just as I thought. Both of them thoroughly warm. Perfect environment for something nasty to grow.

"Second, the nasograph test." He opens up the bottle and takes a sniff. "Whew. Stinky." Now he opens up the carton and sniffs it. "Ugh. Way stinkier. Hey, are you writing all this down?"

"Yeah," you say, "but I think we need to get a little more 'scientific' about this, Zack."

Continue with the mystery

An Access Excellence Science Mystery sponsored by Genentech, Inc.