The Narrative
Imagine this. You and Dustin are still seated in the grass, and Dustin is still telling you about the time he fell into the pantry and landed in Hiero’s palace.
“You said you knew who Archimedes was,” Dustin was explaining, “but I had never heard of him. But I was impressed that he had figured out the problem with Hiero’s crown. So I asked someone, and they said that Archimedes had figured out many problems for Hiero before.”
“Like what?” you ask.
“Like weapons to defend the city,” Dustin says. “And also there was this huge ship that Hiero wanted built, but there were a lot of challenges with that, so Archimedes was kept pretty busy figuring all of those out.”
“That must have been quite a ship if they needed Archimedes to get involved,” you note.
“Yea, it was,” Dustin says. “It was the largest ship the world had ever seen up to that time. They named it the Syracusia. They said that nothing like it had ever been built, that hundreds of skilled workers were sweating over it for a year. They gathered materials from all over the world, including enough lumber to build 60 standard warships. Some of the nails they used weighed 10 pounds! And they bolted lead plates on the sides of the ship to protect it. You know the main mast—the tall beam that they attach the sail to? They needed to make it from one huge tree, but they couldn’t find any trees large enough. They searched all over the place until they found one in the mountains of Italy—a whole other country! Then they had major problems getting that tree down the mountain and back to Syracuse.”
“This sounds like quite a project,” you note.
“Not only that,” Dusting continues. “There was a gym and shaded gardens on the ship. There was a library, a stable with 20 horses, a huge saltwater fish tank. There was a temple to Aphrodite with floors made of agate, and the rest of the ship’s floors were covered with mosaics showing famous stories.”
“Do you know what agate is?” you interrupt.
“No,” Dustin answers, defensively.
“Do you know what mosaics are?”
“No,” Dustin admits again. “But it sounds cool.”
“It is cool,” you agree, and nod for Dustin to continue.
“Well, the ship was meant to be like a luxury cruise ship, but they also wanted it to be safe from pirates and enemies, so they put a lot of weapons on it.”
“Weapons? Like what?” you ask.
“There were eight huge towers on the deck, and inside each tower there were soldiers and archers. And there were cranes with hooks that could reach out and hook enemy ships and drag them in close to be destroyed. And there was a giant catapult. It could hurl huge rocks—like up to 180 pounds—and send them crashing into ships from 600 feet away.”
“You have a surprisingly good memory for details when it comes to weapons,” you note.
Dustin ignores the comment. “So I saw the ship, of course, because I am a time-traveler.”
“Of course,” you grumble, rolling your eyes.
“And when I saw it,” Dustin continues, “I turned to someone and asked them how it was going to float. I mean, it was a huge ship. A real monster. The person said not to worry, because Hiero had hired Archimedes to figure it all out.”
“I am surprised they didn’t ask you to figure it out,” you joke, “since you are such a famous time-traveler.”
Dustin looks hurt and a little angry. “Oh so you think you could figure it out?” he shoots back. “How would you have designed it?”
Activity 1: Discerning Principles
If Hiero had actually asked you to build his ship, could you have designed it to ensure that it floated? Let’s see. Your challenge today is to design a boat, and see how heavy a load it can carry. (If your boat can carry the Syracusia’s 2,000 ton load, then you should feel pretty proud, and you’re probably ready to join Archimedes’ engineering team.)
Let’s start by making some simple observations. We all know that some objects float and some don’t. Rocks don’t float. Rowboats do. What makes the difference? What makes some things float and others sink?
Let’s test a few objects and see if we can discern some principles.
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- Get a large bowl and fill it with water.
- Gather things from around the house and outside of different shapes, sizes, weights, textures, colors, and smells.
- In your journal, list the objects you collected.
- One by one, put the objects you collected into the bowl.
- In your journal, note which ones float and which ones sink.
- Gather the objects that floated into one group, and then gather all the objects that sank into a different group. Then ask: What is similar about the floating objects that distinguishes them from the sinking objects? In other words, what do the floating objects have that the sinking objects don’t?
- Is it the color of the objects? (Like, is it that green objects float and orange objects sink?)
- Is it the texture of the objects? (Like, is it that smooth objects float and rough objects sink?)
- Is it the shape of the objects? (Like, angled objects float but round objects sink?)
- Is it the smell of the objects? (Like, stinky objects float but fragrant objects sink?)
- Is it the weight of the objects? (Like, heavy objects float but light objects sink?)
Hopefully you figured some things out, because you now need to start building a ship.
Activity 2: Applying the Principles
Let’s begin your boat-building career. Your challenge is to build a boat from aluminum foil that can carry cargo. Now if you were to take a block of aluminum and set it in your bowl of water, it would quickly sink to the bottom. You are being asked to make aluminum float—and not only that, but have that aluminum float while carrying extra weight. That sounds crazy, but aircraft carriers and cargo ships do exactly that. What’s the trick?
What you need for this challenge:
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- Your The Laboratory: Apprentice Journal (available on Amazon here)
- Aluminum foil
- A ruler
- A marker
- A bowl of water
- A stack of paperclips, coins, marbles, or something else that will be the cargo in the ship
To start, follow the directions in this video.
At the top of the journal page for this lesson, there is space to record the details of your boat’s design. Draw a picture of your boat, and write down its dimensions (how long, how wide, and how tall it is). Then load it up with cargo (your paperclips, coins, marbles, or whatever else) until it sinks, and record in your journal how much cargo it could hold before it sank.
Your boat carried some cargo, but probably not 2,000 tons. So you are going to need to design a better boat if you are going to keep King Hiero happy. How do you do that? Use the Scientific Method you learned in the previous lesson: Ask, Guess, Test, and Learn.
In the ‘Ask’ section of your journal, write down the question you are asking here. It is probably something like this: ‘How can my boat carry more cargo?’
Then, in the ‘Guess’ section of your journal, record what you think the answer might be. Your guess is going to be a new design feature. Maybe ‘giving it higher sides,’ or ‘giving it a canoe-shape,’ or ‘painting it red.’ (If you want some help on new design ideas, you can follow the directions in this video.)
Once you have done that, it is time to test. Build your new boat with the new design feature you identified. In the ‘Test’ section of your journal, there is space to draw a picture of your boat and to write down its dimensions, just as you did for your first boat. Then load down your new boat with cargo until it sinks, and record how much weight it carried.
Reflect on the results of your test, and record what you found out in the ‘Learn’ section of your journal. Was your guess correct? Did your new design feature improve your boat?
(Do you want to see an aluminum foil boat that can carry a person? There are a few soggy fails in this video, but with some design improvements they figure it out by the end of the video.)
Explanation
Archimedes had some design ideas that he shared with Hiero, and, fortunately, Archimedes knew what he was talking about. Archimedes said he had discovered a principle about floating: “If the ship is equal to, or lighter than, the amount of water it displaces (that is, the amount of water it pushes out of the way to make room for itself), then it will float.”
How does that relate to boat design? Watch this video for an explanation.
As that video explains, even the giant Syracusia could float if it was designed to displace a great deal of water. As you might have noticed when you were designing boats, one way to do that is to make the bottom of the boat big. The bigger bottom can push more water out of the way, allowing the boat to carry a larger load.
What actually happened to the Syracusia? Did it end up on the bottom of the ocean somewhere? Or did Archimedes come through for Hiero once again? Check out this video for the rest of the story.