October 31 – Vampire Function

Math is often called the language of science. And the beautiful thing about that language is that it says the same thing whether you are working in chemistry or biology. Peter and Daniel will learn that as they discover why vampires can’t be real!

It was a bright, sunny fall afternoon. The houses were all decorated with pumpkins, mummies, and ghosts. The sky was clear and the air was crisp with the promise of a cool, clear night just perfect for trick-or-treating. Even better, the sidewalks were piled high with leaves that Peter and Daniel ran through on their way to the school’s annual Fall Festival. The crunch of the leaves and the smell of the air promised great things to come and both of the boys were looking forward to the candy that they would collect that night. Both were in their costumes. Peter had on the cape, fangs, and slicked back hair of a vampire while Daniel had decided to go as a mad scientist, complete with labcoat, black gloves, and goggles.

“It sure is a shame that Mary couldn’t come,” Daniel said after crunching thourgh a particularly large pile of leaves. “Her costume was great! I love Doctor Who.”

“Yeah, she even had the little K-9 on a chain to tow behind her,” Peter replied. “But her dad is pretty strict; if your homework isn;t done, you don;t get to play.”

“Maybe that’s why she gets such good grades.” Daniel felt sorry for Mary; his dyslexia made studying a chore so he knew how it felt to miss a bright afternoon.

“You should talk, Mr. Brain!”

“That’s Dr. Brain to you!” The boys laughed and turned into the school grounds. There at the entrance to the gymnasium was their favorite teacher, Mr. Medes; for the holiday, he was wearing insect wings and a pair of antennas but had painted his face grey and green.

“Hi, Mr. Medes!” the boys chorused. Then Peter asked “I don’t get it. What are you supposed to be?”

“I’m a zombee,” Mr. Medes replied. As the boys groaned at the pun, he explained. “There is a fly that lays its eggs inside of bees. The larva eats the bee’s brain and takes over, creating what biologists call a zombee.”

“So there really are zombies?” Daniel said. “Cool!”

“Are there really vampires, too?” Peter asked.

“Well, there are a lot of animals that drinkt he blood of other animals. There’s the female mousquito who needs the blood to make her eggs.There’s the hagfish, which rasps a hole in other fish with its tongue and sucks their blood. And then there’s the vampire bats; all three species live off of the blood of others. But if you mean creaturees like Dracula, then the answer is no; there can’t be.”

“Why not?” Peter insisted. “If we can have real live zombies that eat brains, why can’t we have real live vampires?”

“Because there would be too many predators and not enough prey,” Mr. Medes replied. “Here, let’s go inside and we’ll do an experiment to show you what I mean.”

At that the boys perked up. They both wanted to be scientists and doing experiments was one of their favorite things. They quickly followed mr. Meddes inside the gym and over to a table.

“Have a seat while I grab some apparatus from my lab,” Mr. Medes said. “I’ll be right back!”

As the boys waited, they speculated on what the experiment would be.

“Maybe he’s got some blood for us to look at,” Peter said. “That would be cool.”

“Nah,” Daniel replied. “It has to be neater than that; I’ll bet he’s got some real, live zombees for us!”

In just a few moments, Mr. Medes returned with a piggy bank in his hands. The boys stared at him, confused.

“A piggy bank? What does that have to do with vampires?” Peter demanded.

“Patience,” Mr. Medes advised. “We’re going to be doing a model of how vampires would interact with humans. And since we can’t use real humans and real vampires in our experiment, we’ll substitute something else. The people will be pennies and the vampires will be nickles. We’re going to need about 100 pennies and 100 nickles.”

With that, he pulled the cork from the bottom of his piggy bank so that the change spilled out. Quickly the three of them sorted the coins and piled up the necessary change. Pouring the rest of the money back into the piggy bank, Mr. Medes began explaining the experiment.

“Here’s the way it works,” he began. “There are twenty vampires, represeented by our twenty nickles. And there are fifty people, represented by fifty pennies. The remaining coins will come into play later. The vampires go first. Peter, you’ll gather up the nickles and shake them in your hands, then drop them on the table. The nickles that land face up get to eat; you’ll take away one penny for every face up nickle because the vampire just killed a person. And then you’ll add a nickle for every person eaten so your vamprie population will grow.”

Peter picked up the nickles and shook them over the table before letting them drop. When they landed, he quickly sorted them into five that landed face up and fifteen that landed face down. Peter then took eight pennies from Daniel’s pile and added eight nickles to his.

“Hah!” Peter said in his best Transylvanian accent. “You people sure are tasty!”

“OK, now it is Daniel’s turn,” Mr. Medes said. “Shake your pennies and then drop them just like Peter did with his nickles. When they land, set the face up ones in groups of four; for every group, you get a new penny.”

Daniel quickly shook up the pennies and let them fall. Sorting them, he found that he had twenty-four face up pennies, so he added six pennies to his pile.

“Hah right back!” Daniel said. “We added more people than you ate!”

“So you both know how to play, right?” At the boys’ nods, Mr. Medes continued. “Then here’s the question: can vampires exist if they eat people?”

“Sure,” came Peter’s response. “My vampires ate eight people but they added thirteen. So we can eat forever and there is no reason that we can’t exist.”

“I dont know,” Daniel said. “You added almost as many vampires as we did people. If you grow too fast or we don’t grow fast enough, we might all get eaten.”

“Well, there is only one way to find out for sure,” Mr. Medes said. “Let’s do the experiment!”

What do you think will happen? Do the experiment!

The boys eagerly nodded and started flipping coins. In Peter’s next round, he had eight face up nickles, so his vampires had eaten eight people and gained eight new members. Daniel did well that round and again had twenty-four face up pennies, so he had six more people added.

“Hey! Not so hungry!” Daniel said.

“We’ll see about that!” Peter crowed. His face fell when just three nickles landed face up but he quickly brightened when Daniel could only muster five face up pennies. “You people sure are slow; you just added one new one!”

As the game continued, the boys started to add sound effects and other silliness. Peter began to chuckle like a B-movie Dracula each time his vampires ate a person. And Daniel cried out “My baby! My baby!” each time he gained a new penny.

Peter gained fourteen vampires in the next round while Daniel only added nine people. And the following round was even more disastrous; sixteen new vampires were created but only four new people. For the first time, the vampires outnumbered the people. The end came swiftly. In each of the next three rounds, far more people were eaten than were born and the vampire population exploded. In the final round, there were nearly a hundred vampires and just thirteen people.

“Wow!” Peter said. “I didn’t think that would happen!”

“Yeah,” agreed Daniel. “For awhile it looked like the people could stay alive but then, BOOM!”

“What you two have just seen is what is known as a population collapse,” Mr. Medes said. “Biologists like to study this because it can tell us things such as how long a disease outbreak will last or how many fish we can take from an area. And, as you’ve seen, it shows that vampires simply cannot exist.”

“How can this one experiment show so much?” Daniel asked.

“Well, the experiment looks pretty specific but when you express it in math, it becomes general. The math doesn’t care whether you are talking about the number of people who catch a disease like vampirism or the number of fish that get caught or the amount of chemicals left in a reaction; it works equally well in all situations,” Mr. Medes explained. “That’s why we say that math is the language of science. It helps us take what we learn in one area and apply it in another.”

“Wow,” Daniel said. “That’s cool.”

“It sure is,” Peter said. “But how did we discover that we could use math to talk about vampires?”

Mr. Medes chuckled. “Actually, Lotka was trying to describe a chemical reaction when he came across this idea. He used math to describe how the reaction happened and discovered that sometimes the solutions led to never-ending chemical reactions. He then applied the idea to biology and created what we call the predator-prey relationship. In our experiment, the vampires are the predators and the humans are the prey. Because the vampires always grow in population, they will always end up eating all of the prey and the humans will always be wiped out.”

“Cool!” Peter said. “So that’s why you said that vampires couldn’t exist. We still have people -”

“Which means that vampires haven’t eaten us all and the only way that they wouldn’t do that is if they don’t exist!” Daniel finished.

“The neat thing is that we do have something very like a vampire,” Mr. Medes said. “Every year, it attacks the human population and tries to convert as many people as possible into its slaves. This model helps groups like the CDC predict just how bad this year’s attack will be.”

“Really? What is it?” Peter asked.

“The flu! Simple diseases like the flu behave a lot like vampires,” Mr. Medes explained. “The only differences are that you are only turned into a flu monster until your body can get better and that we have a vaccine that works against it much better than garlic works on vampires. But it still builds up every year about this time, infects a lot of people, and then has a population collapse when it runs out of victims. And speaking of victims, I think I see a new one over there!”

Peter and Daniel turned to look where Mr. Medes was pointing. In the doorway was Mary, complete with a long scarf, floppy hat, and long coat. Peeking out from behind her was a model of K-9.

“Mary!” the boys chorused. Eagerly, they ran over to bring her into the party and tell her about their new experiment.

May 30 – Tongue Tied

One of the best things about science is how it corrects mistakes. And one of the worst things about popular culture is how it perpetuates them. Today, Daniel, Peter, and Mary discover the truth behind a popular science myth when they get tongue tied!

 

 

It was a bright, sunny Saturday afternoon and life was just about perfect. Daniel had come to visit Mary and Peter that morning and they’d spent several hours experimenting with kites, trying to discover what sort of tail made a kite fly best. What they had discovered was that the person flying the kite was even more important than the tail. Peter’s kites always flew into trees or crashed into the ground. Mary could keep her kites flying but had a very hard time launching them. But Daniel was a natural kite-flyer and could make even the most unlikely of kites soar high above.

To make the day even better, when they’d gotten back to Mary’s back yard, they found that her father had set up a picnic for them, complete with hot dogs, potato salad, three kinds of pickles, and fresh watermelon. The three friends enthusiastically munched through the piles of food, only slowing down once they reached the slices of watermelon.

“Pass the salt, please,” Mary asked.

“I still don’t get it,” Daniel said as he salted his slice of watermelon and then passed her the condiment. “How can adding salt to watermelon make it taste so good?”

“Dunno,” Peter said. “It just does.”

“Is that any kind of attitude for a scientist to display?” Mary’s father chided gently. “A real scientist would try to figure it out.”

“OK, how do we do that?” Peter replied.

“In science, you always start with what you know. What do we know about taste?”

“Well, last year Mrs. Krabapple had us map our tongues with four tastes,” Mary said. “So we know that there are four different tastes and that they are in different parts of the tongue.”

“As a wise man once said, it isn’t what we know that causes us problem; it is what we think we know that really ain’t so,” her father sighed. “Your teacher was wrong on two counts. First, a taste isn’t found in just one part of your tongue. And second, there are more than four tastes.”

“Huh?” the three young scientists chorused.

“This is sort of like the myth that we only use 10% of our brains when we actually use the whole thing. What happened is that a reporter misheard something and told everyone about it.  The tongue story got started when a psychologist by the name of Boring had translated a German paper that showed different parts of the tongue were more sensitive to different tastes. For some reason, this got reported by the popular press as though those tastes could only be sensed in those parts of the tongue. But you can easily prove that this isn’t true,” Mary’s father said.

“How?” Daniel asked.

“Spoken like a true scientist!” Mary’s father beamed. “First, stick out your tongue and dry it off with a napkin. That will make it certain that the taste doesn’t get spread by the saliva in your mouth. Now take a piece of water melon and touch it to the different parts of your tongue – on the front, on each side, in the middle, and in the back. See how you can taste it all over your tongue?”

The three experimenters followed his directions and quickly discovered that he was right. As they finished their experiment, he continued.

“Now watermelon has a lot of sugar in it, so you were mainly tasting ‘sweet’. We can repeat the experiment with the other tastes if you like, but what it will prove is that you have taste buds for every taste on every part of your tongue. There are actually taste buds on your cheeks and in your throat as well.”

“Wow!” Peter said. “Mrs. Krabapple never said anything about that!”

“She may not have known,” Mary’s father replied. “Sadly, many teachers don’t get the support they need in order to teach science properly.”

“But what about the number of tastes?” Mary demanded. “You said that there aren’t four tastes.”

“That’s right,” her father replied. “Depending on how you want to count them, there may be as few as five or as many as thirteen different distinct tastes. The five tastes that just about everyone agrees on are sweet, sour, bitter, salty, and umami.”

“Ohh-what-si?” Daniel asked.

“‘Ooh-mommy’,” Mary’s father repeated. “It is sometimes called ‘savoriness’ or ‘meatiness’ because it is sort of like the taste of a good steak. Those hot dogs you three scarfed down had a lot of umami.”

“That’s pretty neat, but what do the different tastes have to do with why we like watermelon better with salt on it?” Peter asked.

“Ah, I think I’ll let you figure that out for yourselves. Stay here for a second!”

With that, Mary’s father went back into their kitchen. Mystified, the three young scientists looked at each other. From the kitchen, they heard a variety of cabinets being opened and closed and the clink of plates. After a few minutes, Mary’s father came back out carrying five different plates. As he put the plates on the table in front of them, he explained what the experiment would be.

“In each plate, we’ve got an example of a different taste. The first one has salt for saltiness. The second plate has baking cocoa for bitterness. The third plate has vinegar for sourness. the fourth plate has low-sodium soy sauce for meatiness. And the last plate has sugar for sweetness. And here are a bunch of water crackers; they don’t really have much in the way of flavor,” he paused as Peter grabbed a cracker and tasted it.

“Ugh!” Peter exclaimed. “It tastes like cardboard.”

“Right!” Mary’s father said. “Now here’s the experiment. First, you’ll dip a cracker into each of the different tastes and eat it. That will help you get familiar with the tastes. Then you’ll try dipping the cracker into two different tastes and then eat it. What do you think will happen?”

“Well, the two different tastes will just be two different tastes in our mouths,” Peter said. “Nothing will change.”

“I don’t know,” Daniel said. “Remember what happened when we added salt to the watermelon?”

“That’s right!” Mary exclaimed. “I’ll bet that the tastes change each other somehow.”

“Well, there’s only one way to be sure,” Mary’s father said. “Start tasting!”

What do you think will happen? Try the experiment yourself!

Intro

The three young scientists quickly grabbed crackers and dipped them into each of the plates. From their grimaces, it was clear that they didn’t much care for the tastes by themselves. But something changed when they started dipping the crackers into to tastes before eating them.

“Hey!” Peter excitedly said. “Did you guys try this? Sweet plus bitter – it tastes almost like a candy bar!”

“Cool!” Daniel replied. “I like sour and salty – it tastes like a pickle!”

“And salty plus umami is wonderful!” Mary added. “This is so delicious!”

“Can you figure out why it is so good,” Mary’s father asked. “You’ve definitely got enough information to form a hypothesis now.”

“Well, one taste by itself isn’t very good,” Peter said. “And it only hits one set of taste buds.”

“But two different tastes together are good, ” Mary said.

“And they hit two different sets of taste buds,” Daniel added. “So maybe the more different taste buds that get excited, the better the food tastes?”

“That’s right!” Mary’s father said. “That’s why the best recipes always have several different tastes in them. Cookies always have sweet and salty. Soda usually has sweet and sour. Soup has umami and salty. And so forth. Companies spend billions of dollars trying to find the perfect combination of different flavors. For example, what do you think would happen if you used umami with your watermelon instead of salty? Or if you used bitter?”

“I don’t know,” Peter started.

“But we sure want to find out!” Daniel and Mary chorused together. Smiling, the three scientists grabbed watermelon slices and began their most edible experiment of the day.

October 31 – Time To Prey

Math is often called the language of science. And the beautiful thing about that language is that it says the same thing whether you are working in chemistry or biology. Peter and Daniel will learn that as they discover why vampires can’t be real!

It was a bright, sunny fall afternoon. The houses were all decorated with pumpkins, mummies, and ghosts. The sky was clear and the air was crisp with the promise of a cool, clear night just perfect for trick-or-treating. Even better, the sidewalks were piled high with leaves that Peter and Daniel ran through on their way to the school’s annual Fall Festival.  The crunch of the leaves and the smell of the air promised great things to come and both of the boys were looking forward to the candy that they would collect that night. Both were in their costumes. Peter had on the cape, fangs, and slicked back hair of a vampire while Daniel had decided to go as a mad scientist, complete with labcoat, black gloves, and goggles.

“It sure is a shame that Mary couldn’t come,” Daniel said after crunching thourgh a particularly large pile of leaves. “Her costume was great! I love Doctor Who.”

“Yeah, she even had the little K-9 on a chain to tow behind her,” Peter replied. “But her dad is pretty strict; if your homework isn;t done, you don;t get to play.”

“Maybe that’s why she gets such good grades.” Daniel felt sorry for Mary; his dyslexia made studying a chore so he knew how it felt to miss a bright afternoon.

“You should talk, Mr. Brain!”

“That’s Dr. Brain to you!”  The boys laughed and turned into the school grounds. There at the entrance to the gymnasium was their favorite teacher, Mr. Medes; for the holiday, he was wearing insect wings and a pair of antennas but had painted his face grey and green.

“Hi, Mr. Medes!” the boys chorused. Then Peter asked “I don’t get it. What are you supposed to be?”

“I’m a zombee,” Mr. Medes replied. As the boys groaned at the pun, he explained. “There is a fly that lays its eggs inside of bees. The larva eats the bee’s brain and takes over, creating what biologists call a zombee.”

“So there really are zombies?” Daniel said. “Cool!”

“Are there really vampires, too?” Peter asked.

“Well, there are a lot of animals that drinkt he blood of other animals. There’s the female mousquito who needs the blood to make her eggs.There’s the hagfish, which rasps a hole in other fish with its tongue and sucks their blood. And then there’s the vampire bats; all three species live off of the blood of others. But if you mean creaturees like Dracula, then the answer is no; there can’t be.”

“Why not?” Peter insisted. “If we can have real live zombies that eat brains, why can’t we have real live vampires?”

“Because there would be too many predators and not enough prey,” Mr. Medes replied. “Here, let’s go inside and we’ll do an experiment to show you what I mean.”

At that the boys perked up. They both wanted to be scientists and doing  experiments was one of their favorite things. They quickly followed mr. Meddes inside the gym and over to a table.

“Have a seat while I grab some apparatus from my lab,” Mr. Medes said. “I’ll be right back!”

As the boys waited, they speculated on what the experiment would be.

“Maybe he’s got some blood for us to look at,” Peter said. “That would be cool.”

“Nah,” Daniel replied. “It has to be neater than that; I’ll bet he’s got some real, live zombees for us!”

In just a few moments, Mr. Medes returned with a piggy bank in his hands. The boys stared at him, confused.

“A piggy bank? What does that have to do with vampires?” Peter demanded.

“Patience,” Mr. Medes advised. “We’re going to be doing a model of how vampires would interact with humans. And since we can’t use real humans and real vampires in our experiment, we’ll substitute something else. The people will be pennies and the vampires will be nickles. We’re going to need about 100 pennies and 100 nickles.”

With that, he pulled the cork from the bottom of his piggy bank so that the change spilled out. Quickly the three of them sorted the coins and piled up the necessary change. Pouring the rest of the money back into the piggy bank, Mr. Medes began explaining the experiment.

“Here’s the way it works,” he began. “There are twenty vampires, represeented by our twenty nickles. And there are fifty people, represented by fifty pennies. The remaining coins will come into play later. The vampires go first. Peter, you’ll gather up the nickles and shake them in your hands, then drop them on the table. The nickles that land face up get to eat; you’ll take away one penny for every face up nickle because the vampire just killed a person. And then you’ll add a nickle for every person eaten so your vamprie population will grow.”

Peter picked up the nickles and shook them over the table before letting them drop. When they landed, he quickly sorted them into five that landed face up and fifteen that landed face down. Peter then took eight pennies from Daniel’s pile and added eight nickles to his.

“Hah!” Peter said in his best Transylvanian accent. “You people sure are tasty!”

“OK, now it is Daniel’s turn,” Mr. Medes said. “Shake your pennies and then drop them just like Peter did with his nickles. When they land, set the face up ones in groups of four; for every group, you get a new penny.”

Daniel quickly shook up the pennies and let them fall. Sorting them, he found that he had twenty-four face up pennies, so he added six pennies to his pile.

“Hah right back!” Daniel said. “We added more people than you ate!”

“So you both know how to play, right?” At the boys’ nods, Mr. Medes continued. “Then here’s the question: can vampires exist if they eat people?”

“Sure,” came Peter’s response. “My vampires ate eight people but they added thirteen. So we can eat forever and there is no reason that we can’t exist.”

“I dont know,” Daniel said. “You added almost as many vampires as we did people. If you grow too fast or we don’t grow fast enough, we might all get eaten.”

“Well, there is only one way to find out for sure,” Mr. Medes said. “Let’s do the experiment!”

What do you think will happen? Do the experiment!

 

 

The boys eagerly nodded and started flipping coins. In Peter’s next round, he had eight face up nickles, so his vampires had eaten eight people and gained eight new members. Daniel did well that round and again had twenty-four face up pennies, so he had six more people added.

“Hey! Not so hungry!” Daniel said.

“We’ll see about that!” Peter crowed. His face fell when just three nickles landed face up but he quickly brightened when Daniel could only muster five face up pennies. “You people sure are slow; you just added one new one!”

As the game continued, the boys started to add sound effects and other silliness. Peter began to chuckle like a B-movie Dracula each time his vampires ate a person. And Daniel cried out “My baby! My baby!” each time he gained a new penny.

Peter gained fourteen vampires in the next round while Daniel only added nine people. And the following round was even more disastrous; sixteen new vampires were created but only four new people. For the first time, the vampires outnumbered the people. The end came swiftly. In each of the next three rounds, far more people were eaten than were born and the vampire population exploded. In the final round, there were nearly a hundred vampires and just thirteen people.

“Wow!” Peter said. “I didn’t think that would happen!”

“Yeah,” agreed Daniel. “For awhile it looked like the people could stay alive but then, BOOM!”

“What you two have just seen is what is known as a population collapse,” Mr. Medes said. “Biologists like to study this because it can tell us things such as how long a disease outbreak will last or how many fish we can take from an area. And, as you’ve seen, it shows that vampires simply cannot exist.”

“How can this one experiment show so much?” Daniel asked.

“Well, the experiment looks pretty specific but when you express it in math, it becomes general. The math doesn’t care whether you are talking about the number of people who catch a disease like vampirism or the number of fish that get caught or the amount of chemicals left in a reaction; it works equally well in all situations,” Mr. Medes explained. “That’s why we say that math is the language of science. It helps us take what we learn in one area and apply it in another.”

“Wow,” Daniel said. “That’s cool.”

“It sure is,” Peter said. “But how did we discover that we could use math to talk about vampires?”

Mr. Medes chuckled. “Actually, Lotka was trying to describe a chemical reaction when he came across this idea. He used math to describe how the reaction happened and discovered that sometimes the solutions led to never-ending chemical reactions. He then applied the idea to biology and created what we call the predator-prey relationship. In our experiment, the vampires are the predators and the humans are the prey. Because the vampires always grow in population, they will always end up eating all of the prey and the humans will always be wiped out.”

“Cool!” Peter said. “So that’s why you said that vampires couldn’t exist. We still have people -”

“Which means that vampires haven’t eaten us all and the only way that they wouldn’t do that is if they don’t exist!” Daniel finished.

“The neat thing is that we do have something very like a vampire,” Mr. Medes said. “Every year, it attacks the human population and tries to convert as many people as possible into its slaves. This model helps groups like the CDC predict just how bad this year’s attack will be.”

“Really? What is it?” Peter asked.

“The flu! Simple diseases like the flu behave a lot like vampires,” Mr. Medes explained. “The only differences are that you are only turned into a flu monster until your body can get better and that we have a vaccine that works against it much better than garlic works on vampires. But it still builds up every year about this time, infects a lot of people, and then has a population collapse when it runs out of victims. And speaking of victims, I think I see a new one over there!”

Peter and Daniel turned to look where Mr. Medes was pointing. In the doorway was Mary, complete with a long scarf, floppy hat, and long coat. Peeking out from behind her was a model of K-9.

“Mary!” the boys chorused. Eagerly, they ran over to bring her into the party and tell her about their new experiment.

 

 

 

July 18 – Doom From The Sky

Peter and Mary were in her backyard on a sultry summer evening, racing after fireflies.

“Hey! I caught one!” Mary shouted with happiness.

“Ooh! Pretty!” said Peter.

“Thank you!”

“Not your firefly; look up there!”

Following Peter’s outstretched arm, Mary looked up just in time to see the end of a meteor as it blazed across the sky.

“I wonder what makes them glow like that,” she mused. “Do you think that they are radioactive?”

“No; it is probably sunlight reflecting off of them like those noctilucent clouds that Mr. Medes told us about in science class last year.”

“Well, it is nice to know that you paid attention to something that I said,” came a voice from behind them.

“Mr. Medes!” the pair exclaimed.

“What are you doing here?” continued Mary.

“Your mother asked me over to see her new telescope,” he replied. “But it looks as if we won’t need it to see the meteor shower.”

“That’s right; they move too quickly to see in the telescope. But what makes them glow like that?” asked Peter.

“That’s an interesting question,” Mr. Medes said. “To answer it, you’ll need to rub your hands together. What do you think will happen?”

“They’ll make noise,” Mary said promptly.

“They’ll get hot,” said Peter.

“OK, you’ve made your predictions – now find out what the answer is!” commanded Mr. Medes.

Eagerly, the pair began to rub their hands vigorously together.

“Hey! My hands are getting warm!” said Mary.

“We learned about this in Boy Scouts,” said Peter. “When you rub things together, the friction between them makes heat. You can even use it to make fire by rubbing sticks together!”

“That’s right,” said Mr. Medes. “When you rub things together, you are taking one type of energy and turning it into another. You are taking energy of motion”

“Kinetic energy!” interjected Mary.

“That’s right; you are turning kinetic energy into heat energy. You can do the same thing by hitting a piece of metal with a hammer. Do it fast enough and you’ll heat the metal up so much that it glows!”

“But what does that have to do with meteors?” asked Peter.

“Well,” Mr. Medes said, “People used to think that it was the friction of the meteorite racing through the air that made them glow. And it does have some effect; some of the little bits that break off are torn away by friction. But there’s something else that has an even bigger effect. To understand it, you’ll need a basketball and an air pump.”

“I’ve got those in my garage!” Peter exclaimed. He quickly raced next door to get the equipment and handed it to Mr. Medes when he got back.

“Wow! That was quick! You almost started to glow yourself,” Mr. Medes joked. Taking the air pump,he plugged it into the basketball. “I want you both to feel the basketball. Tell me, does it feel warmer or cooler than the air around it?”

Looking puzzled, Peter and Mary put their hands on the basketball.

“They feel about the same,” Mary said.

“Yeah, it feels like everything else out here,” Peter added.

Mr. Medes nodded. “That’s because the air and the basketball are in what scientists call ‘thermal equilibrium’; the ball gains heat from the air about as quickly as it gives heat back. Now what I want you to do is take turns pumping air into the basketball. You’ll need to add fifty pumps each. What do you think will happen?”

“The ball can’t get much bigger,” Peter said. “It is already full of air. So it will be just the same.”

“I don’t know,” Mary replied. “If we are adding more air to the ball, then something has to happen. Maybe it will change temperature?”

“There’s only one way to find out,” Mr. Medes said. “Start pumping!”

What do you think will happen? Do the experiment!

 

 

 

 

 

 

 

 

 

“Ladies first!” Peter said, handing the pump handle to Mary. She started eagerly enough, but soon was huffing and puffing each time she pushed the air pump’s handle down.

“Gosh, this is hard!” Mary said. Finally, she finished her fifty pumps. “Your turn!”

“Stand back and watch what a boy can do!” Peter said. His first few attempts went smoothly enough, but pretty soon he was as out of breath as Mary had been. “Maybe I spoke too soon!”

As soon as Peter had finished adding the air to the basketball, Mr. Medes picked it up and said “look at the ball. Is it any bigger?”

When the two shook their heads “no”, he continued “But add all of that air had to do something. Touch the basketball and let me know what you feel.”

Peter and Mary put their hands on the basketball. After a moment, Peter’s face lit up with understanding.

“The ball is warmer than it was!” he exclaimed. “Adding all of that air made it warmer somehow!”

“That’s right,” Mr. Medes said. “When you added the air, you compressed a lot of stuff into a small space. That meant that the stuff couldn’t move as far without running into something, so it started moving in shorter but faster ways. And that means…”

“That the temperature went up!” Mary exclaimed. “Because temperature is just the motion of the molecules; the faster they move, the hotter they are!”

“That’s close enough for now,” Mr. Medes said. “There are a few differences between temperature and heat, but those only matter to a scientist. Your idea is right, and that’s the important thing. When you compress air, it heats up. And that explains the meteor’s glow.”

“How?” Peter asked. “I still don’t get the connection.”

“Those meteors that you see in the sky are little tiny grains of dust that are moving very, very fast. The slowest of them are moving at 24,000 miles per hour and the fastest are trucking along at 94,000 miles per hour. That is so fast that the air can’t get out of the way as the meteor heads toward Earth. So when the dust grain enters the atmosphere, it compresses the air in front of it.” Mr. Medes pushed one hand with the other to show what he meant. “The air transfers some of that heat to the meteor and that heats up the meteor until it glows. Sometimes the outer skin of the bigger ones melt and little drops fly off as it goes through the atmosphere,”

“Is that what makes the little trails that come off of the meteor as it goes through the sky?” asked Peter.

“Yes. Sometimes the meteor hits the air so hard that it is blasted apart, like the one in Russia. And sometimes the meteor is so big that it makes it all the way to the ground,” Mr. Medes continued. “That makes a crater that we call an astrobleme, or ‘star wound’. You’ve probably heard about the one that hit about 65 million years ago.”

“That’s the one that killed the dinosaurs!” Mary said.

“Well, let’s just say that Chicxulub didn’t do them any favors,” chuckled Mr. Medes. “And it isn’t the only one. There are literally hundreds of astroblemes on Earth, and even more on the Moon. And now that your mother has her telescope set up, let’s take a look at those.”

Smiling, the three turned to look through the telescope at the face of the Moon.

 

 

June 27 – Silver Lining

Scientists do their best work when faced with contradictory results. If you always get just one result, then what you are investigating isn’t very interesting. But if sometimes you see one thing and sometimes you see another, then that’s Nature’s way of telling you that you are on the verge of learning something truly neat. And that’s what happens to Mary, Peter, and Daniel today as they look for the silver lining.

The atmosphere in Peter’s living room was just perfect for the Secret Science Society’s annual “Mad Science Movie Marathon”. While Mary, Peter, and Daniel indulged in huge bowls of popcorn, plates of caramel apples, and glasses of swamp juice (lemon soda with food coloring and raisins), classic monster movies from the 1950s ran on the DVD player and a fierce storm raged outside. They had laughed at The Mummy’s bad hieroglyphics, howled along with The Wolfman, and shivered as Frankenstein brought his creation to life with the lightning on the screen being echoed by real thunder from the storm outside. Naturally, just as the villagers gathered up their pitchforks to explain the homeowner association rules to poor, mad Victor, a bright flash of light and an ear-shattering crack told of a near-miss and the television and lights and all other power went off in the house.

“Don’t worry,” Peter said. “I know where the emergency flashlights are.”

“Rats!” said Daniel. “It was just getting good!”

“I wonder how long it will take to get the power back,” Mary mused. “And what will we do while we wait?”

“I’ve got a better question,” Daniel said. “Why is it dark?”

“Huh?” said Peter as he came back into the room with three flashlights.

“Think about it,” Daniel said. “When you look at a cloud on a sunny day, the cloud is white. Sometimes it even seems brighter than the sky around it. So why is it dark under a rain cloud? Aren’t they all the same thing?”

“I hadn’t thought about it,” Mary replied. “But you are right. Rain clouds are dark but regular clouds aren’t. I wonder why?”

“Well, it is too wet outside to go ask Mr. Medes,” Peter said. “Do you think my mom might know?”

“Might know what?” Peter’s mother asked as she came into the room with more flashlights. “I thought you might need these but I see you’ve got things well in hand!”

“Daniel asked something that we don’t know the answer to,” Mary said. “Why is it dark when it rains if clouds are white?”

“Well, there’s no shame in not knowing something. The only shame is if you don’t try to find out what the answer is,” Peter’s mother replied. “And it turns out that the answer to your question happens to apply to my work. So, yes, I know the answer.”

“What is it?” Daniel asked.

“Well, would you rather I told you or would you prefer to do an experiment?”

“Experiment! Experiment!” the three young scientists chorused.

“OK. Peter, go get that bag of marbles from your room,” his mother directed. “And I’ll go get some clear plastic bags from the kitchen. We’ve already got flashlights, so we’re all set.”

Peter quickly went to his bedroom and grabbed the bag of marbles. As he came back into the den, his mother returned with four plastic bags. Taking the marbles from Peter, she filled each bag with marbles before sealing it and handing it to one of the scientists.

“OK,” she said as she filled her bag with marbles. “This would work better if the marbles were clear instead of having that swirl of color in the middle, but it is close enough for our purposes. What I want you to do is shine your flashlight through the bag of marbles cross-wise so that the light goes through the ‘thin way’. What happens?’

“I can see the light but it is a bit fuzzy,” said Daniel.

“And the edge of some of the marbles gets bright,” added Mary.

“Good,” said Peter’s mother. “Now, what I want you to do is shine the light through the bag of marbles the long way. But, before you do, tell me – what will you see?”

“Probably the same thing we just saw,” said Peter. “The light will be fuzzy and there will be some bright edges.”

“I don’t know,” said Daniel. “Maybe having more marbles means that the light won’t make it through somehow.”

“Or maybe we’ll just see bright edges,” added Mary.

“Well, there’s only one way to find out!” Peter’s mother said.

What do you think will happen? Try the experiment yourself!

The three turned their baggies longwise and looked at the flashlight shining through. But instead of a bright light, they only saw a dull, fuzzy beam. The marbles had dimmed the flashlight beam just as clouds dulled sunbeams.

“Wow!” exclaimed Peter. “The light got a lot darker.”

“And most of the bright edges are gone!” said Mary.

“But why?” asked Daniel.

“The reason for this is the same reason that the bottom of the ocean is dark and that radio waves don’t travel very far in a nebula,” Peter’s mother said. “It is a type of physics known as optics. When the light from the sun or from a flashlight beam hits an object, three things happen: reflection, refraction, and absorption.”

“Reflection like a mirror?” Mary asked.

“Exactly! You may have noticed that you can see your face in a very still pond; that’s because some of the light that hit the top of the water was reflected back at you,” Peter’s mother explained. “The same thing happens with our marbles and with the raindrops that make up a cloud. Some of the light gets reflected back off of every raindrop. As you get deeper into the cloud or the cloud gets thicker, less and less light makes it through.”

“Oh, so that’s why rainclouds clouds are dark! They are thicker than other clouds!” Peter said.

“No, that’s only part of the explanation,” his mother replied. “There’s also refraction; that’s what happens when the light gets bent by the raindrop. Instead of traveling through and continuing in a straight line like a toothpick in an olive, the raindrop makes the path of the light shift a little so it looks more like a broken toothpick in an olive. And because the angle of the break is different for each color of light, when the angle is just right, you can get -”

“A rainbow!” Daniel said. “Is the bent light what made the edges of the marbles seem bright?”

“That’s exactly right,” Peter’s mother said. “Taken together, we sometimes refer to reflection and refraction as scattering. But reflection and refraction are only part of the reason that rain clouds are dark. The third reason is – ”

“Absorption!” Mary said. “Is that like when a sponge absorbs water?”

“Not quite,” Peter’s mother said. “With a sponge, you can always get the water back out by squeezing it. But when light gets absorbed by a raindrop, it gets changed into heat. That added energy might make the raindrop warm up a very little bit or it might be re-radiated as infrared light. And since we can’t see in infrared, that makes it dark in the center of a rain cloud and under one, too.”

“But what does that have to do with the ocean bottom?” Peter asked.

“You can think of the ocean as a whole bunch of raindrops jammed together,” his mother replied. “As the light goes through the ocean, some of it gets absorbed. Interestingly, the depth that the light makes it down to depends on the wavelength of the light. Colors like red have very long wavelengths and make it deeper into the ocean than colors like blue. In addition, water like to scatter the shorter wavelength colors like blue; that’s why the ocean looks blue – more of that color gets reflected to your eyes. Taken all together, the amount of light that you can see in the ocean drops by 90% for every 75 meters. So if the ocean was as deep as a skyscraper is high, the bottom floor would get only 10% as much light as the top one would.”

“Cool!” Daniel said. “But what does that have to do with your work?”

“I’m a planetologist,” she replied. “That means that sometimes I look at planets before they are born, when they are just big clouds of gas and dust called nebulae. The gas and dust in a nebula will scatter and absorb light just like the water in the ocean or the raindrops in a cloud. And by measuring how the light from stars behind the nebula is scattered and absorbed, we can estimate the thickness of the cloud and even learn what it is made of. We’ve found water, ammonia, formaldehyde, and even amino acids in nebulae across the galaxy. There are even some scientists who think that life on Earth started thanks to those amino acids.”

“Neat!”

Just then, the power came back on.

“Well, it looks as if your creation has come back to life,” Peter’s mother said. “So I’ll just leave you three to your movies.”

“Thanks mom!” Peter said, his fingers already on the remote, ready to start the movie again as the three sat back down absorbed once more in the morality tale on the silver screen.

June 20 – Tongue Tied

One of the best things about science is how it corrects mistakes. And one of the worst things about popular culture is how it perpetuates them. Today, Daniel, Peter, and Mary discover the truth behind a popular science myth when they get tongue tied!

 

 

It was a bright, sunny Saturday afternoon and life was just about perfect. Daniel had come to visit Mary and Peter that morning and they’d spent several hours experimenting with kites, trying to discover what sort of tail made a kite fly best. What they had discovered was that the person flying the kite was even more important than the tail. Peter’s kites always flew into trees or crashed into the ground. Mary could keep her kites flying but had a very hard time launching them. But Daniel was a natural kite-flyer and could make even the most unlikely of kites soar high above.

To make the day even better, when they’d gotten back to Mary’s back yard, they found that her father had set up a picnic for them, complete with hot dogs, potato salad, three kinds of pickles, and fresh watermelon. The three friends enthusiastically munched through the piles of food, only slowing down once they reached the slices of watermelon.

“Pass the salt, please,” Mary asked.

“I still don’t get it,” Daniel said as he salted his slice of watermelon and then passed her the condiment. “How can adding salt to watermelon make it taste so good?”

“Dunno,” Peter said. “It just does.”

“Is that any kind of attitude for a scientist to display?” Mary’s father chided gently. “A real scientist would try to figure it out.”

“OK, how do we do that?” Peter replied.

“In science, you always start with what you know. What do we know about taste?”

“Well, last year Mrs. Krabapple had us map our tongues with four tastes,” Mary said. “So we know that there are four different tastes and that they are in different parts of the tongue.”

“As a wise man once said, it isn’t what we know that causes us problem; it is what we think we know that really ain’t so,” her father said. “Your teacher was wrong on two counts. First, a taste isn’t found in just one part of your tongue. And second, there are more than four tastes.”

“Huh?” the three young scientists chorused.

“This is sort of like the myth of Brontosaurus which was really an Apatosaurus and the myth that we only use 10% of our brains when we actually use the whole thing. What happened is that a reporter misheard something and told everyone about it. What happened is that a psychologist by the name of Boring had translated a German paper that showed different parts of the tongue were more sensitive to different tastes. For some reason, this got reported by the popular press as though those tastes could only be sensed in those parts of the tongue. But you can easily prove that this isn’t true,” Mary’s father said.

“How?” Daniel asked.

“Spoken like a true scientist!” Mary’s father beamed. “First, stick out your tongue and dry it off with a napkin. That will make it certain that the taste doesn’t get spread by the saliva in your mouth. Now take a piece of water melon and touch it to the different parts of your tongue – on the front, on each side, in the middle, and in the back. See how you can taste it all over your tongue?”

The three experimenters followed his directions and quickly discovered that he was right. As they finished their experiment, he continued.

“Now watermelon has a lot of sugar in it, so you were mainly tasting ‘sweet’. We can repeat the experiment with the other tastes if you like, but what it will prove is that you have taste buds for every taste on every part of your tongue. There are actually taste buds on your cheeks and in your throat as well.”

“Wow!” Peter said. “Mrs. Krabapple never said anything about that!”

“She may not have known,” Mary’s father replied. “Sadly, many teachers don’t get the support they need in order to teach science properly.”

“But what about the number of tastes?” Mary demanded. “You said that there aren’t four tastes.”

“That’s right,” her father replied. “Depending on how you want to count them, there may be as few as five or as many as thirteen different distinct tastes. The five tastes that just about everyone agrees on are sweet, sour, bitter, salty, and umami.”

“Ohh-what-si?” Daniel asked.

“Umami,” Mary’s father repeated. “It is sometimes called ‘savoriness’ or ‘meatiness’ because it is sort of like the taste of a good steak. Those hot dogs you three scarfed down had a lot of umami.”

“That’s pretty neat, but what do the different tastes have to do with why we like watermelon better with salt on it?” Peter asked.

“Ah, I think I’ll let you figure that out for yourselves. Stay here for a second!”

With that, Mary’s father went back into their kitchen. Mystified, the three young scientists looked at each other. From the kitchen, they heard a variety of cabinets being opened and closed and the clink of plates. After a few minutes, Mary’s father came back out carrying five different plates. As he put the plates on the table in front of them, he explained what the experiment would be.

“In each plate, we’ve got an example of a different taste. The first one has salt for saltiness. The second plate has baking cocoa for bitterness. The third plate has vinegar for sourness. the fourth plate has low-sodium soy sauce for meatiness. And the last plate has sugar for sweetness. And here are a bunch of water crackers; they don’t really have much in the way of flavor,” he paused as Peter grabbed a cracker and tasted it.

“Ugh!” Peter exclaimed. “It tastes like cardboard.”

“Right!” Mary’s father said. “Now here’s the experiment. First, you’ll dip a cracker into each of the different tastes and eat it. That will help you get familiar with the tastes. Then you’ll try dipping the cracker into two different tastes and then eat it. What do you think will happen?”

“Well, the two different tastes will just be two different tastes in our mouths,” Peter said. “Nothing will change.”

“I don’t know,” Daniel said. “Remember what happened when we added salt to the watermelon?”

“That’s right!” Mary exclaimed. “I’ll bet that the tastes change each other somehow.”

“Well, there’s only one way to be sure,” Mary’s father said. “Start tasting!”

What do you think will happen? Try the experiment yourself!

 

 

 

 

 

The three young scientists quickly grabbed crackers and dipped them into each of the plates. From their grimaces, it was clear that they didn’t much care for the tastes by themselves. But something changed when they started dipping the crackers into to tastes before eating them.

“Hey!” Peter excitedly said. “Did you guys try this? Sweet plus bitter – it tastes almost like a candy bar!”

“Cool!” Daniel replied. “I like sour and salty – it tastes like a pickle!”

“And salty plus umami is wonderful!” Mary added. “This is so delicious!”

“Can you figure out why it is so good,” Mary’s father asked. “You’ve definitely got enough information to form a hypothesis now.”

“Well, one taste by itself isn’t very good,” Peter said. “And it only hits one set of taste buds.”

“But two different tastes together are good, ” Mary said.

“And they hit two different sets of taste buds,” Daniel added. “So maybe the more different taste buds that get excited, the better the food tastes?”

“That’s right!” Mary’s father said. “That’s why the best recipes always have several different tastes in them. Cookies always have sweet and salty. Soda usually has sweet and sour. Soup has umami and salty. And so forth. Companies spend billions of dollars trying to find the perfect combination of different flavors. For example, what do you think would happen if you used umami with your watermelon instead of salty? Or if you used bitter?”

“I don’t know,” Peter started.

“But we sure want to find out!” Daniel and Mary chorused together. Smiling, the three scientists grabbed watermelon slices and began their most edible experiment of the day.

June 13 – Round And Round

One of the best things about science is how an observation in one area can apply to something in a completely different area. Our friends Peter and Mary will discover that and much more in today’s episode of the Secret Science Society!

If you have a friend, then you know that the only thing more fun than having your friend come to your birthday party is getting to go to his. And the only thing more fun than that is getting to play with the goodies that you got at the party. And both Peter and Mary had been lucky at their friend Daniel’s party. Mary had won a toy car when they played charades and Peter was coming home with a helium balloon he won during the trivia contest. As they watched for their ride home, they played with their new prizes.

“Hey! There’s my mom!” Peter said.

“Thanks again for a great party, Daniel!” Mary said. Her father had brought the two of them to the party and she was going to ride back home with Peter; living next door had some advantages.

“Glad you could come,” Daniel said. As the new kid at school, he didn’t have many friends yet, but sharing experiments with Peter and Mary had already turned them into a close-knit group. “And thank you for the lab coat! I can’t wait to try it out! And the air cannon is great – I couldn’t believe it when it blew out my candles!”

“Glad you like it,” Peter and Mary chorused as they headed out the door and clambered into the car.

“Are you both buckled in?” Peter’s mother asked.

“Yes!” the two said, and the car pulled out. Mary put her toy car on the seat between her and Peter, and Peter let his balloon float in the air above his knees. As the car stopped at a stop sign, Mary suddenly grabbed for the toy car.

“Hey!” Mary exclaimed. “The car’s trying to escape!”

“Well, that beats being hit in the face by a balloon!” Peter replied. As the car sped away from the stop sign, Mary’s toy car rolled back and Peter’s balloon swung toward the front of the car.

“That’s weird,” he said. “My balloon goes the opposite direction of your car. I wonder why?”

“If you’ll wait until we get home,” Peter’s mother said, “I can show you. Even better, we can do an experiment to find out the answer.”

Since experiments were one of Mary and Peter’s favorite things to do, they cheerfully agreed. Almost as soon as the car stopped in Peter’s driveway, the two young scientists hopped out and looked expectantly at Peter’s mother.

“OK,” she laughed. “Let’s go do some science!”

Taking them into the kitchen, she gave each of them a raw egg.

“What does this have to do with balloons and toy cars?” Mary asked.

“You’ll see,” Peter’s mother replied. “What I want you to do is spin the egg as quickly as you can. Once it is spinning, put your hand on the egg for a second to stop the spinning and then take your hand off. What will happen?”

“The egg will just sit there,” Mary said.

“I don’t know,” Peter said. “It might act like the car somehow.”

“Well, there’s only one way to find out,” Peter’s mother said. “On the count of three, spin!”

What do you think will happen? Do the experiment!

 

 

 

 

 

“One, two three!”

Peter and Mary quickly spun their eggs. As soon as the eggs started to spin around, they put a hand on them and stopped the egg. Then they took their hands away and watched in amazement as the eggs started to spin again!

“Hey! What gives?” Mary asked.

“That egg is a lot like the inside of the car,” Peter’s mother replied. “Just as the car is a hard shell of steel filled with air, an egg is a hard shell of calcium carbonate filled with liquid. And both air and egg white and every other physical thing in the universe have something in common – they all have mass.”

“But that just makes things weigh a lot and keeps stuff on planets,” Peter objected. “It can’t make something spin after you stop it!”

“Actually it can,” his mother said. “You’re right that mass is what gives things weight. But mass also has another feature; it creates inertia – the tendency for something to keep moving in the direction it is going. When you spun the egg, you started the liquid inside spinning. And though you stopped the outside of the egg, you weren’t able to stop the liquid inside thanks to its inertia. So when you took your hand off of the egg, the liquid made it start spinning again.”

“But what if I used a hard boiled egg?” Mary asked.

“Then everything would be stuck together and the egg wouldn’t start spinning again; that’s one way to tell if you have a hard-boiled egg or a raw one,” Peter’s mother replied. “But the same thing happens in a car that happens in that egg. When the car started moving, inertia kept the stuff inside of it from going with it right away.”

“Is that why you get pushed back in the seat when my dad drives?” Mary asked.

“Yes; it takes a little time for the car’s cushions to give your body the same speed as the rest of the car and that’s what pushed you back. And that’s why your toy car rolled back when the car started moving forward – it didn’t have the same speed as the car and tried to stay in place. And when the car stopped, your toy car rolled forward; if you hadn’t caught it, then it would have had an accident.”

“So that’s why we wear seat belts!” Peter said. “They help hold you in place and keep you from moving forward when the car gets in an accident and stops suddenly.”

“Right,” his mother said. “So can you figure out why the balloon went the opposite way to the toy car?”

“The balloon must have been pushed by something, or its inertia would have kept it right above my knees,” Peter said.

“The air!” Mary exclaimed. “Your balloon is lighter than air! When the car starts up, the air gets pushed back by its inertia. Because the balloon is lighter than air, it gets pushed forward when the air moves back!”

“That’s exactly right! Well done!” Peter’s mother looked at the clock. “But it is getting late and Peter has enough inertia in the morning already – he doesn’t need any more!”

“OK! Thanks for the ride back home,” Mary said . “And thanks for the experiment!”

Smiling, she headed out the door and over to her house as her brain filled with ideas for using inertia.