the sound of science

I was skiing the other day and heard loud booms. The ski patrol was trying to trigger avalanches by detonating explosives.

I heard similar booms when I was younger but did not give them much thought. Now, however, maybe because I am surrounded by sound at work, I started paying more attention.

As the explosives went off I was surprised because it seemed like I could feel the sound while sitting on the chairlift.

How was this possible?

Sound travels in waves similar to waves we see at a beach. They have a top called a “peak,” and a bottom called a “trough.” A sound’s size is called “amplitude.” The pitch we hear is dependent on the frequency.

My little yappy dog has a high frequency and small amplitude, while the low booms from the ski patrol have a low frequency and large amplitude.

As a large amplitude sound wave travels through the air, it pushes the air forward. Think about seeing “the wave” at sporting events or watching dominoes fall. When we feel the blast we are feeling the force of air actually being pushed forward.

Other sound waves are subtler. For instance, take your hand, put it on your throat and read the next sentence out loud making your voice high and low pitched. The vibrations you feel are your vocal folds, or chords, vibrating due to air coming out of your throat and making sound waves.

If you think about music, there are many instruments with chords that vibrate.

But what about the instruments that do not have chords?

Wind instruments make sound by vibrating air inside them by using different mechanisms. Trombones have a mouthpiece that musicians blow into causing their lips to vibrate. The sound from the vibrating travels down the body and is amplified by the opening at the end. Other wind instruments like a saxophone rely on vibrations from reeds as air is blown past them.

When sound emerges from any item, it travels until it runs into something or has no more energy. If a sound wave hits something, it bounces back and travels in the opposite direction. That is why we can hear echoes so well in areas where there is a lot of room for the sound to bounce from place to place. It is no coincidence opera houses are shaped they way they are.

Try it yourself at the band shell at Memorial Park. You’ll discover that it is a lot easier to hear someone talking while they are inside the shell, than it is if they were talking over by the swings. This is because the sound is echoed out of the shell toward where you are standing in the grass.

This really is only the first note in your favorite song when it comes to sound. We did not even get to the ear, which has a canyon full of interesting scientific intricacies when it comes to hearing

BEE - AUTIFUL!

When my family went on summer vacation we always drove.  While in the car, my
sister, Mac, would read and I, being the budding young scientist, would observe the
surroundings.  I noticed white boxes lining the countryside and asked my parents about them. To my amazement, they were bee boxes, full of bees kept by people to get honey and to pollinate their crops. This intrigued me!

We were recently driving on vacation and I saw boxes off in the distance. I wanted to know where honey came from, the role of bees, and why people would keep bees.  Even Mac, who finally noticed the boxes wanted to know more about the bees and the white boxes.

To fully appreciate bees, honey, and pollination, let’s start at the beginning.  Stick your head out of a window and you may smell the beautiful aroma of flowers blooming. Not only do these flowers smell nice, they are visually appealing as well.  This is no accident. These characteristics are designed to attract pollinators (insects, hummingbirds, bats, and bees) to the flower to help spread genetic material from plant to plant.

Pollinators like bees are drawn to showy plants to feed on nectar.  To reach the nectar, which is located close to the bottom of the flower, they inadvertently brush against the male part of the flower—the stamen—that holds pollen.  The pollen stays on the bees' bodies while they transport it with them from flower to flower.

When these pollen besotted bees arrive at a new flower for more nectar, they brush against the female reproductive part of the flower—the stigma—waiting for the pollen. Once the pollen comes into contact with the stigma, the ovule is fertilized and that plant’s life has just become fulfilled with future children.  The connection between pollinators and flowers is called a "mutualistic relationship" because both parties are being used and reaping benefits.  And we, too, reap benefits from such relationships. Consider that honeybees pollinate close to $15 billion worth of crops in the US alone each year. That's
a lot of strawberries, broccoli, and beans, to name a few.

Once bees have reached their maximum intake for nectar they return to the hive.  I must warn you, what happens next borders on the line of disgusting, so, if you like honey, you may not want to read past here.  To transform nectar, which has water and yeast in it, into honey, bees regurgitate it until it reaches its desired quality. Yummy! If they did not do this, the yeast would cause it to ferment.

Knowing now that I am putting bee vomit in my coffee in the morning does not deter me.  In fact, I think I will relish the fact that I am reaping the rewards of a beautiful partnership between flowers and bees.  I, however, do not think the same can be said for Mac, she has not been the same since finding this out.

Burn baby burn

Growing up I had a love-hate relationship with fire. I loved it for smores and Helena's cool fire trucks. I hated forest fires because I thought they were very scary. When the Elkhorn Mountain and the Gates of the Mountains burned in 1989, I'd wake up every morning and check to make sure those wild fires were not coming to get me.

On a recent camping trip I realized fire still intrigues me. While trying to start the
campfire with damp wood, I was reminded that I've often thought it would be sweet if wood
could spontaneously combust. That will never happen though, because a wood fire needs to
have three things for it to be "successful": fuel, oxygen, and an ignition source. Once these three
requirements are met, we can break out the sticks and marshmallows.

There is much more to the science of fire than the three requirements. For that stack of camp wood to become fire, the woody material needs to ignite and decompose. It decomposes in a variety of forms but to keep it simple, think smoke, charcoal, and ash. Charcoal, by the way, is almost pure carbon and some is simply wood that's been heated to remove the volatile gases that create smoke. This is why the hot charcoal in your barbeque grill cooks without smoke.

While looking at our campfire, it occurred to me I really didn't know much about the flames of the fire. I tried to decipher its properties in my head but the flame possessed none of the common properties of solids, liquids or gases. A little quick research revealed a simple explanation.

A flame is neither a solid, a liquid, nor a gas. A flame is plasma, a substance in which some of the particles are free to move rather than be contained.  These moving particles are the rising carbon atoms and emit the incandescent light we see.  If you watch a fire, you might notice the color of the light varies as the flames seem to dance of the logs.

The flames can range in color from blue at the hottest spot to a yellowish/orange at their coolest location.  The "dancing" of the flames we see is the product of gravity.  If we could have a small campfire in the Space Shuttle, the fire would be a sphere, about the size and shape of a basketball!

When it is time to go to bed, we always put the fire out so it does not get away and start a forest fire.  There are a number of ways to do this; we usually pour water on the fire.  This disrupts the combustion process by rapidly cooling the fire down.

I hope this helps in your campfire endeavors for the rest of the summer. Remember to pay attention to warnings in your area to make sure it's safe to build your campfire. I don't want to keep an eye peeled on wild fires coming to get me!

Playground physics phun

I was at Barney Park recently riding on a swing and having a great time.

"Why don't more adults ride swings," I asked one of my older students—let’s call
him Newton.

"Because they look ridiculous," Newton replied.

I asked if I looked ridiculous and Newton said that I did not need to ride a swing
to look ridiculous.

I like Newton, so I decided not to bump him off his swing.

Despite Newtons’s accusation, I continued to ride the swing and thoroughly enjoyed myself while flying through the air.

As I sat there, I wondered why I moved forward when I pumped my legs and then went in reverse. Then I saw my students on the merry-go-round hanging on for dear life. I realized many of the toys on the playground can be explained using laws from Science. I had to share my excitement so the next time you take your children to Barney or Lockey or any other of Helena's great parks, you too can explain the science behind the swinging.

When I was growing up I would wait in line for my chance to defy gravity and feel as though I was flying on all of the park toys—from the swings to the slides. Was I really defying gravity or was I just altering the effect gravity had on me? Since my fascination appears to continue, I'll keep the focus on swings; but first gravity should be explained.

Gravity is much more complex than knowing what goes up must come down. It is the force of attraction between any two objects. Small objects and objects far away from each other do not have much attraction. Here in Helena, the force of attraction is humongous because Earth is so massive and we're close to the center. The farther we move away from the center of Earth though, the less attraction Earth has on us. This is why astronauts can space walk and why we actually weigh a little less when we climb Mount Everest.

When you sit on a swing, it's almost as if you're sitting on a pendulum, similar to a Newton’s cradle. If you throw your weight back while hanging onto the chains, this action causes a reaction of moving the swing forward. Once you reach your maximum height on one side, the attraction between you and Earth pulls you back down. Since you are on a pendulum, rather than smacking into the earth, your momentum is carried back to the other side.

We continue to swing until we stop putting work into it. Once we stop pumping our legs the swing eventually stops.  This is because friction from the air combined with gravity is too much to overcome.

I try to explain all this to my daughter when we go to  the park and she looks at me as if I am ridiculous. It must be because she's only two years old, because as far as I know she's never met Newton.

A touch of gray

It is official. I have completed another full rotation around the sun—my 31st— and thus I am a year older. I love this time of year, not only because of my annual birthday cake, but also because of all the changes. Temperatures are cooler, snow is in the mountains, and leaves are starting to show their brilliance. It is all of these autumnal happenings and end-of-season beauty that make me love October.

When I was growing up, my sister and I gave my dad a hard time about saying his hair color was listed as "black" on his driver’s license when clearly he was going gray. He responded by saying he was not going gray, rather, his hair color was salt-and-pepper and they would not let him put that on his license. Well, now that I have made many trips around the sun, my hair is also starting to turn a wee bit salty. Is it because my daughter is now 2½ years old or because a shock of salt-and-pepper hair equals wisdom?

It turns out hair growth is much more complicated than the vegetative growth seen in a Chia pet, which is how I often think of hair growth. Each strand of hair emerges from its own follicle and involves three stages: a growth stage that lasts 2-7 years; a shut-down stage that lasts 10-20 days, and then another growth stage. If, however, the subsequent growth stage sputters, there is a good chance hormones are acting on the follicle causing hair growth to slow, or maybe even stop for good.

Before one is able to see brown, red, or blonde hair, the growth that begins within the follicle is pure white. Hair does not pick up color until it leaves the follicle, and the mechanism for color is generated by melanin. Melanin is a pigment that not only gives color to hair but to eyes and skin as well.  There is dark melanin called "eumelanin," which determines brown and black hair color, and reddish/yellowish melanin called "pheomelanin," which determines red and blonde hair. The amount of melanin we carry determines color, something we cannot control.

A child's hair color often resembles that of his or her parents', which is no coincidence. The amount and type of melanin we acquire is dependent on what we get from our parents. Genetics—not those loveably unruly 2 year olds—likewise determines when one's hair makes the transition to salt-and-pepper.

This is the part of the story that becomes a scientific gray area. Scientists know a reduction of melanin causes hair to change color, and that the timing of the change is similar within families. Yet they do not know why melanin levels decrease. There is speculation like increased levels of hydrogen peroxide but as yet no definitive answers.

So, like me seeing one more round of autumn colors, my new shade of salt-and-pepper hair just signifies that I am getting older. I did not need my hair to tell me that though. I get the hint from my students whenever I try to act cool and hip.

Those not so pearly whites

I do not remember when my baby teeth came in so I had no idea how painful it was.  When my daughter’s teeth came in, it was clear she was in pain. Ironically, while she was teething, I too started to teeth to feel her pain; it must have been my paternal instinct.  Having been through the experience, it does not feel good.

While we were sharing the experience, the teeth that were coming in were quit different.  She was getting her first of her baby teeth, me being much older and wise; I was getting the last of my permanent teeth, my wisdom teeth.  I recently had my wisdom teeth pulled and all this teething got me curious.

As with everything I have researched, I was immediately amazed how little I knew about teeth.  Our teeth develop in much the same way as non-mammals teeth do.  The interaction between two embryonic layers of tissue of our developing skin come together, fold or change shape.  They then both secrete proteins that will form the structures.  The process in which teeth form is the same process in which feathers, hair, scales, even sweat glands form.  While our teeth form the same way, that does not mean that they behave the same way.

We have two sets of teeth, while other animals can have less or more.  Sharks can grow new teeth almost every two weeks.  Our Baby teeth start developing in utero around six weeks while permanent molars start to form around week 20.  We keep our “baby” teeth until about age six at which time we start to get our second set of teeth.  Current research suggests that periodontal ligaments play an important role in tooth eruption. Once our permanent teeth come in, they do not grow any longer which is different in some rodents.

When I was growing up, we had a rabbit that gave me nightmares because his teeth were long and creepy.  Rodents’ teeth keep growing while maintaining them by gnawing and chewing.  This did not work for our rabbit so we had to cut his teeth with a fingernail clipper so they did not grow too long.

These unique characteristics of teeth are very useful to Scientists.  They can tell what the unknown animals diet was based on their teeth.  They also use them to identify fossil species and their relationships.  Teeth withstand time very well because they are so hard.  The hard part of the tooth is the outer layer and called enamel while the inside is made of dentin.

I was able to see these parts on my teeth because much to my wife’s dismay I kept my wisdom teeth so I could study them.  I have studied them in depth and they my wife is tired of them being under my pillow so if there is a tooth fairy, please stop by and pick them up.

Gobble Gobble

It is hard for me to decide what my favorite thing about Thanksgiving is. It heralds what I like to call the Fantastic Three - family, football, and food!

While I normally eat more than I should, I thought this year I might learn more about the food I so love, and about some of the food on the table I can do without.

Every year in my family the day's discussion is the same leading up to the grand feast, "Is the turkey going to be dry?" Luckily, we have not had the displeasure of having too dry of a turkey.

Because of that, I am then left with a decision I agonize over for the weeks leading up to the big day, "Am I going to eat white or dark meat?" In these times of reflection, I often wonder what the difference is between the white and dark meats.

The meat we eat from the turkey is very similar to chicken because turkeys and chickens are very similar species of domestic fowl that spend much of their time on the ground, not in the air. This means much of their time is spent walking or running. The delicious white meat - the breasts and wings are the muscles Thanksgiving turkeys almost never use because of their lack of flight. The dark meat comes from the muscles that are used more often - the legs and thighs.

These muscles have different colors because the more active the muscle, the more oxygen it needs from the blood vessels. These types of muscles are actually called "slow twitch," while the muscles of the white meat are called "fast twitch."

I have always heard that the turkey we consume makes us tired because of an essential amino acid called tryptophan. It is essential, but our bodies are not able to produce it, therefore we must include it in our diet. While turkey contains tryptophan, it is likely not the only food at the table that contains it. Cheese, for instance, has as much or more tryptophan than turkey.

It is also important to mention the sleep-inducing effects of the amino acid require an empty stomach to kick in. It is the cornucopia of food, relaxed holiday spirit, and inclination to overeat that's most likely responsible for Uncle Tim falling asleep on the couch after the meal.

Consider the holiday decisions one has to make about potatoes. I do not like sweet potatoes but because of "Sam I Am" and his green eggs and ham, I have given yams a try. Sorry Sam I did not like yams. No matter how much sugar and butter, they tasted similar to sweet potatoes. It turns out, however, that 95 percent of yams in the world are grown in Africa, so unless you go to one of the many international markets in Helena, the festive orange tubers on your Thanksgiving table are likely sweet potatoes.

I hope you have a wonderful Thanksgiving and that this information helps to make your dinner a little more enjoyable, even if you are a sweet potato fan. Happy Thanksgiving!