Anechoic and Reverberation Chambers field trip

When I was little, my dad would sometimes take me over to the Science Building where he worked at BYU, and show me all the coolest things: the top of the pendulum, the giant ground sloth skeleton, the wave machine, and best of all the anechoic chamber. I LOVED going into this room where there were no echoes, no outside sounds—only the most silent, muffled air I'd ever experienced. And I would have given anything if, for this field trip, I could have just called up Dad and asked him to get out his key and go with us to the anechoic chamber again! But…now that he's gone…we had to go through the regular channels. And it wasn't too hard: you can just sign up for a tour here at the BYU Acoustics Outreach page. On the night we went, we were the only people in the group, so it was great.

The anechoic chamber has been remodeled since I was young: back then it was all made of yellow insulation, and the foam pieces weren't quite so aggressively triangular! So it was cool for me to see this updated version. Our tour guide was really knowledgeable and answered all the children's questions with great patience. (The little ones were kind of nervous about the wire mesh floor, and I remember feeling just the same when I was young! It feels very precarious. It's actually strong, though—they can put a grand piano on it with no problem!)

My only regret on this field trip was that I didn't get to walk around yelling and shouting with as much wild abandon as I felt like I could when I was there with my dad. :) And I wish I had thought to make a recording while we were in there! But, never fear: here is a recording made in another university's anechoic and reverberation chambers which will give you the idea.

Another bonus was that, unbeknownst to me, BYU now also has a reverberation chamber, which is basically the opposite of the anechoic chamber. And that was really cool too!

You can see all the hard angled surfaces they have hanging above the floor, all to increase reverberation.

The most amazing thing in this room was the demonstration our guide gave us of standing waves. He turned on a loudspeaker that put out a loud, low sound, and then we walked around the room listening. Because of the reverberation, the waves reflect back on themselves, and that means they sometimes make nodes, or places where the peaks and troughs of the waves actually cancel each other out. We had understood this in theory, but experiencing it in real life was really striking! You'd walk around, wanting to cover your ears because of the loudness of the sound, and then suddenly you'd come to a spot where the sound just…dampened. It became almost soft, as if you'd covered your ears or walked into a different room. And those places were the nodes. We loved this!

I didn't record that phenomenon, but here is a short sample of how a voice sounds in the reverberation chamber: 

Sound Wave activities and resources

Goldie feeling vibrations (from music coming out of the speakers) pass through a balloon

Some sound wave resources: 

Video about a wave machine that makes the biggest (manmade) waves in the world

Animations that show how sound is a pressure wave. When you see the waves so often simplified visually into sine waves, it's easy to forget what kind of waves they really are!

This video explains harmonics and overtones, two things I have always struggled to understand. Maybe if I were a violinist I'd have gotten it earlier!

This virtual oscilloscope is really cool

This is amazing: scientists using standing waves to levitate objects (called acoustic levitation).

And here are some beautiful patterns made with resonance

This video shows the ever-popular trick of breaking a glass with sound. You can see the waves forming in the glass in some of our pictures here,

This lady does overtone singing—or in other words, singing two notes at once! It is eerie and beautiful and amazing. I can't believe she can do this!!

Here's a video about some high amplitude sound research going on at BYU

Here are some wave activities we did as part of our Water Unit

We also investigated interference effects and other wave properties of light (part of our Light Unit)

This site will tell you how to make a string telephone. Except it never works very well, in my experience.

These pictures show an activity did where we investigated the sound-absorbing properties of different materials. (Something like this.) We stuffed various materials into containers and then listened to which were the most "muffling."

Sound and Percussion Homeschool Unit and Lesson Plan

We did a unit on Light last year, so it seemed like we ought to do a unit on Sound too! I love our physics-related units, though every time they make me wish my dad were still alive so he could be our guest lecturer (and help explain everything to me!). Dad helped me do a science fair project when I was in elementary school where I got to use an oscilloscope from his office, and I loved it. I felt so important. :)

I considered, briefly, making this into a Music Unit as well, but I quickly realized that would be too much. Sound and Music are so entertwined, though, that it made sense to at least cover the percussion instruments, especially since those are so fundamentally about sound and vibration. I consider myself a percussionist too, even though my main instrument has always been the piano and that's what I majored in—because I played in the drumline and percussion section in high school, and I also played percussion with one of the university orchestras during my first year of college. I've always loved percussion ensembles! In all their forms. 

One book I read on my own to prepare for this unit was called The Sound Book, and I LOVED it. It's by an acoustic engineer—or maybe he's a physicist?—who went around the world seeking "sonic wonders of the world."  Here is an interesting article about it, and here is the author's website with links to recordings of some of these sites (and other sounds, like birds). It is an awesome site and I recommend it. The recording of the lyrebird is one of my favorites! But the comparisons of a balloon popping in different sites (like in an anechoic chamber vs. a mausoleum) are pretty cool too.

A documentary we watched and  really liked was called Note by Note, and showed the making of a Steinway 9-foot grand piano over the course of a year. Everything is done by hand, and there are so many interesting details! You can see how each piano has its own distinct sonic character.

We also really enjoyed Organworks, a documentary showing different pipe organs around the world and talking about how they were made, changes to the pipe organ over the years, etc. The host of the show was quite entertaining and it was just generally a lot more absorbing than you might think, reading the description. Although I admit we tend to like stuff like this anyway. :)

Some previous activities we've done in our homeschool that are music and sound-related are:

Making a glass armonica

Making rubber-band "lutes"

Making homemade drums and mallets

Listening to examples of birdsong in music

And here's my Pinterest Board for this Unit, with other links and ideas for activities.

The atomic bomb

We did a whole unit on Nuclear Energy a few years ago. It was one of our favorite units! You can find all the posts about that unit aggregated here.

The Nuclear Museum in Albuquerque.

Hydrogen bombs vs. atom bombs

Great article on why we dropped the atomic bomb. And some more good resources on the same subject. Definitely worth watching and teaching. I found a real lack of good information on this subject elsewhere, as most children's books and other modern resources have a sort of glib "we all know better now" sensibility on the subject.

Abe and I LOVED this book, Bomb, by one of our favorite authors, Steve Sheinkin. There is SO MUCH intrigue and so many behind-the-scenes details I had never before heard about. It reads like a mystery novel.

I can also recommend this book (for adults and older children), Hiroshima Diary, which is a journal written by a doctor in Hiroshima in the weeks immediately following the Hiroshima bomb. It is fascinating, sad, and surprisingly good-humored as well. The author seems like a pretty amazing man.

Piston, Jet, and Rocket Engines

Engines! So interesting. We learned about the basic four-stroke engine, as well as diesel engines, during our Train Unit. And early planes used this type of piston engine. See this animation for a demonstration.

(In fact, this is one of our favorite sites ever—it shows animations of different kinds of engines at work. Certain of the children could watch this site, mesmerized, for hours at a time. :))

Later, the jet engine was invented, and there are several types of jet engine: Turbofan/turbojet engines (high- and low-bypass); Turboprops; and Turboshafts. It took us a while to get them straight, but this site does a good job of explaining the differences.

Here's another site that talks about types of jet engine.

We also learned about ramjets and scramjets which are used in rocket propulsion and hypersonic flight.

Here's a "boring" (self-described) animation of a jet engine at work. :)

This site has some good information on engines.

As does this one, including parts of an engine.

Here's a simple activity to demonstrate how rocket propulsion works. We tried this with a long balloon and with a round one. The round one worked MUCH better (more volume of air, I suppose).

The balloon being propelled along the string!

A video about how jet engines work. And on the same subject, another video we really liked.

Sonic booms are so interesting! Here are two videos about them.

Homemade Hovercraft

Well, it's not as cool as this one. But, it's pretty cool to see this little balloon hovercraft at work. And it just takes a minute to make. Instructions are here (or a thousand other places on the web.)

If you want to see it, you know…hovering (really just sliding around), you can watch this enthralling video.

Parts of an Airplane

Sebastian always loves to draw and label things. (He spent his free time drawing this hyper-accurate plane mural one day.) He knows the parts of a plane far better than I do. But, for the benefit of the rest of us, we spent a day learning about the control surfaces of an airplane. I will never again be bored when I have to sit looking out the window at the wing of a plane! There are lots of interesting things going on on those wings! :)

This site shows how to make a paper glider that uses flaps and elevators to move in different ways. It's a good hands-on way to experiment with how and why these surfaces affect the plane the way they do.

Here's Abe giving a brief demonstration of that.

Here is a worksheet for filling in the parts of an airplane, and what they do.

And here is the answer key for that worksheet.

Aerodynamics and the Forces of Flight

You can't swing a cat in the Aviation Education world without hitting something about "The Four Forces of Flight." There's no shortage of resources, but I'll include a few of our favorites.

This site is just great, all around. It talks about aerodynamics, forces, propulsion, materials, and so forth, and it has lots of good little animations and videos.

This is a very good discussion of the effects besides Bernoulli's principle that act on an airplane to help it fly. When I emailed my physicist brother about the fact that we were studying aviation, he immediately wrote back, "Did you run into any controversy about whether or not Bernoulli's principle really makes them fly?  There's a perennial 'Bernoulli!'  'No, angle of attack!' discussion, as if they both can't apply." Ha! And we HAD run into it. This site does a good job of showing that multiple factors are involved.

Here's another good overview site, with some activities.

This video about the four forces of flight was thorough, and entertaining.

This is a really fun lesson plan about flight. This is where we got the idea for our "drag chute," pictured above and below. It's a very effective illustration of how strong drag can be!

We also had fun making "Magnus Flyers," which we learned about from this video. They are very interesting little gliders! You can see Sebastian demonstrating how they work here:

Helicopters

Sometimes people in movies call helicopters "HE-LOs." Why? I don't understand. Shouldn't it be HELIs? Hmm.

After we learned about Leonard Sikorsky and the invention of helicopters (which was interesting…I had never before thought of a helicopter rotor as a moving wing. But it makes sense! Instead of going fast, so the wind will rush over your wing and create lift…you make your WING "rush under" the WIND! Brilliant.) we made a bunch of paper helicopters and tried to learn about which shapes were most effective.

We used this basic template, and then tried every possible variation. Large blades. Long bodies. Looped blades. Thin blades. Thick paper. Twisted paper. And then the children had a heyday dropping them all off of the balcony.

Here you can see them coming down in all their glory.

And here Abe demonstrates some of his design variants.

A few other resources:

This guy made a homemade helicopter out of drones.

Here's a cool helicopter rescue.

And here's an article and video on the group who won, after years and years, the Sikorsky Prize for a human-powered helicopter!

Complex Machines and Rube Goldberg

At the end of this Simple Machines section of our Robotics Unit, we had a fun day learning about Rube Goldberg Machines and making our own! It was hard work, but the children were SO proud of themselves when they actually got one to work!

After talking about some of the ways simple machines can be put together, we read some of Rube Goldberg's actual cartoons from this book. Some of them are really hilarious. The children liked me reading the descriptions and pointing to each part.

There are tons of awesome and funny Rube Goldberg machines online. Some of our favorite videos (some less on-point than others):

A funny Honda Commercial

"Dog Goldberg" machine

This machine made by high school students is pretty fun

This is sort of silly, but it has Rube Goldberg himself in it

The children LOVED this one by OK Go

And this one was our absolute favorite!! We watched it over and over.

We also watched this strange and mesmerizing movie (no words, just the machine working until it finally fades out. There's no grand ending, but the children still wanted to watch it multiple times.)

There were complicated and messy contraptions all over the house for several days after this.

We decided to try to make a toothpaste-squeezing machine like the one the children made in this post. I left it totally in the boys' hands (Daisy and Junie were napping) and it took them most of the day with lots of frustration and failed attempts—but they finally made it work! They were so happy! 

And, just for fun, here is Seb with his homemade "jet engine"

Simple Machine Collages

The children made collages using whatever they could find around the house to depict the six simple machines. I liked them. The above is Sebby's.

Abe's collage

Daisy's

Malachi's

And even Junie made one. :)

Simple Machines: Wheels and Axles (and gears)

I guess I didn't take any pictures of our wheel and axle activities, but I'll include a few links.

First of all, I thought it was interesting to think of a wheel as simply a type of lever—one that rotates around 360 degrees. This video I mentioned on the Screw post, plus this other video about wheels, were really entertaining and informative.

This page is full of good ideas for wheel-related activities. They also made a waterwheel, which is something we did during our water unit a few years ago. It's really fun.

We chose to study gears along with wheels, and here are some gear activity ideas.

Another gear video.

We also talked about ratios and how they relate to gears.

And just in case you've ever wondered what the difference is between a gear and a sprocket, you can find out here!

To show how wheels can help you measure things, we made surveyor's wheels or measuring wheels, sort of like these described here.

We looked at the gears on our bikes and noticed how, just like with levers, increasing the size of the spokes or pedals can change your mechanical advantage.

We watched a couple videos about how wheels are even used in the natural world! For example, these rolling salamanders and caterpillars use the principle of the wheel to escape from danger.

And these leaf-hoppers actually have microscopic gears to ensure that both their legs spring at the exact same time when they jump. Amazing!!

Simple Machines: Pulleys

Pulleys are so fun! The concept of a block-and-tackle (multiple pulley configuration) was new to me, so I found it really interesting to test out why multiple pulleys make lifting easier. It makes sense when you think of the distance/effort tradeoff found in all the other simple machines!

This is a fun activity to help illustrate that concept.

And this is a good video about pulleys.

Here's a fun lesson plan with lots of good pulley activity ideas, like a pulley tug-of-war.

But really, the most fun of all was just experimenting with pulleys to lift things up and down from the balcony. We have these pulleys, which we used, and I borrowed a bunch of old spools (plastic thread spools and wooden spools) from my mom and just let the kids have at it. They came up with some great configurations. Daisy made a tiny paper flag and proceeded to hoist it up and down with great fascination and delight.

Malachi labeled a bucket "2000 Pounds" to make it more impressive :)

Abe had some elaborate multi-pulley system going on.

As did Sebby. Figuring out how to secure them to the balcony while still turning freely was kind of complicated.

I even found Marigold quietly inserting straws into spools and trying to make her own pulleys!

Another of Seb's efforts

Such a fun day!

Simple Machines: Levers

Onto the second category of simple machines: levers! First, we just talked about levers themselves (wheels and pulleys had their own dedicated days). Levers are so fun to play with. We found examples of the different classes of levers around the house. Here's one site that gives a description of each lever class. We had several books on this.

I also think this popsicle-stick chain reaction would be a fun activity to do when studying levers!

We had a great time playing around with levers: changing the length, position of the fulcrum, etc., and seeing what happened. It was pretty easy to lift Goldie! :)

Harder to lift Seb.

Even harder to lift Abraham!

Next, we made catapults. Making catapults is always fun, but we particularly liked this new design we discovered. Some catapults we've made in the past are kind of flimsy, but this one was sturdy—and easy enough to make that even the littler ones could do it by themselves, once they saw how the basic triangle component was constructed. The guy that made up this catapult has a great website with notes on castles and sieges and other catapult designs to try. If we'd been making these for a Middle Ages Unit instead of a Simple Machines unit, we would have tried out some other designs too.

You can find another catapult design (using a spoon) here.

We shot marshmallows and Hershey's kisses with our catapults. Fun!

It was a pretty impressive way to see the power of a lever!

And here's a bonus picture of the children using some levers on the "Archimedes Playground" at the Museum of Natural Curiosity. Fun!