Designing a Clock

In the third and final unit of Light, Sound, and Time, we learned about Time. Moreover, we studied how gravity affects time and how time and space are related. We also looked at different time telling devices and instruments like pendulums and sundials. For the math section of the unit, we learned how to figure out longitude and latitude, how to calculate arc length, and how to calculate the period of a pendulum. For our Action Project, we were asked to design a time telling device based off of our research we did on ancient clocks.

For my clock, I combined the main ideas from each unit into one device. The clock I designed uses Light and Sound to communicate the Time. In order to tell the time with light, the device starts dim and gradually increases/decreases the brightness as the day goes on. While when the peak of brightness happens is programmable, it would originally be set to noon to mimic the real sun. In order to tell time with sound, a constant sound is emitted throughout the day with a increase/decrease in frequency as the day goes on.

Similar the light aspect of the clock, the sound tells time by increasing/decreasing the frequency and can also be programmed to have the peak happen at different times of the day. The program that the device would be set on when it was first turned on would be to start emitting a sound with a frequency of 150 Hz at 12am. For 12 hours until noon, the sound would increase in frequency at a rate of 0.4861 Hz per minute. Once it hits the peak of 500 Hz it would start to decrease at the same rate until it hit 12am again to repeat the cycle. Also, the volume is adjustable and comes with the option to toggle it on and off so the sound is not bothersome.

Like we learned in unit two, the frequency of the sound wave is tied to the pitch of the sound. The higher the frequency of the wave, the higher the pitch. Also, we used the equation 340.29 m/s (speed of sound)= wavelength x frequency. If we wanted to test this equation, we could look at the lowest frequency of the clock (150 Hz) and find its wavelength by dividing the speed of sound by 150 Hz. So, 340.29/150= 22.686. The wavelength of a wave with a frequency of 150 Hz is 22.686 m.

Primarily this clock was made to be a cool and new way to tell time. However, it also allows people who are either blind or deaf to see or hear time. People who need this device to tell time are more likely to buy it so that is why it was designed with those people in mind. But, there is no limit on who can enjoy the device. Also, because there is the option to program the cycle of the sound and light, the user can make it so they wake up to a soothing dim light and a low but relaxing tone.

The idea of using light to tell time is not new. The most common example of how ancient civilizations practiced this is the sundial. The earliest record of the use of the sundial goes all the way back to ancient Egypt. To tell time, the sundial relies on the sun's change in position in the earth's sky. As time goes by, the shadow casted by gnomon (the part in the middle of the sundial that sticks upward) gets moved around the face of the sundial.  To read the time, people just see where the tip of the shadow is casted around the numbers on the face (just like a traditional analog clock). My clock is  similar to this old time invention because of its use of light. However, my design is in no way an improvement of this ancient clock. The sundial would be a way more accurate way to tell time than my device would be. However, my device was not made to be a precise way of keeping track of time. It was more for a novelty and to help those who cannot see a normal clock.

The measurements of the clock would be approximately 5in Tall x 10in Long x 3 in Wide. Because of this, the volume would be around 150 in^3.

Citations

Marie, Niclas. "When Time Began: The History and Science of Sundials." Time Center. TimeCenter,

n.d. Web. 26 Feb. 2017.

Building a Guitar

In the second unit of my STEAM course Light, Sound, and Time, we learned all about sound. By looking sound both in a science perspective and a mathematical perspective, we were able to learn how sound travels and how we can use math to calculate different features of the wave. For our Action Project, we were asked to make a makeshift guitar. By doing this, we could demonstrate both our knowledge of the math behind waves and how sound travels through a guitar.

Diddley Bow (2017) LS

In our internal investigation, we looked at how sound travels. What we discovered was that sound travels at a speed of ~343 meters per second. We also learned how the amplitude of a sound wave affects the volume and how the frequency and wavelength affect the pitch. In my makeshift guitar, the sound gets created by strumming the sting. Then, the vibrations travel down the length of the string and into the tin can. There, the sound gets amplified and the sound waves go out the open end of the can.

Harmonics (2017) LS

To make my guitar, I used a tin can, a piece of wood, screws, a battery, and a guitar string. The string I used was 0.02 in thick. I first put a hold in my can with a sharp object. Then, I secured the tin can with one screw on each side. To put the string on, I winded the string on one each on each side of the guitar, making sure to pull it tight and run it through the hole in the tin can. You can hear me playing my diddley bow here.

Diagram (2017) LS

The calculations I did on my guitar were based off of the trapezoid shape that the string makes with the top of the wood. I turned the top half of the trapezoid into a triangle to use trigonometry to find the measurements of some of the angles. The length of the string from he can to the battery was 13.5 in, the length of the wood from the can to the battery was 13 in, the height from the top of the wood to the string by the tin can was 0.5 in, and the height from the top of the wood to the string by the battery was 0.25 in. I used the inverse tangent of angle y to find it's measurement then used that information and my knowledge of triangles to find the rest of the angles. I also found the volume of the tin can by using the formula v=pi*r^2*h and I got 35.5 in^3. Finally, I found the thickness of my string to be 0.02 in.

Calculations (2017) LS

Building a Camera

In the first unit of my STEAM course Light, Sound, and Time, we learned about the many different aspects of light. During our internal investigation, we explored light waves, radiation, and the electromagnetic spectrum. We also learned about similar triangles and graphing skills to help us understand the math concepts behind the waves of light. For our Action Project, we had to make a camera and use it to show our knowledge on the behavior of light and reflection/refraction. To demonstrate our mastery of the math learned in the internal, we applied our knowledge of similar triangles to create a diagram of how our camera captured the light.

LS Camera (2017) LS

In order to capture the light of an image, my camera has a very small pinhole opening in the front as well as a cover to prevent light from entering the camera while I'm not taking a picture. When light enters the pinhole, it gets inverted and projects the image on the other side of the camera. To capture an image, I put a piece of photosensitive paper inside it and let it sit out with the pinhole exposed for 2 minutes However, for some reason, the picture I took did not come out right and just showed darkness. Along with the photo taken with my camera, I also did a photogram. In order to do this, I placed objects on photo paper and while in a dark room, shone light over the objects and paper for 5 sec and then developed the photo.

When constructing my camera, one of the first things I did was paint the entire inside of it black. This is because black absorbs light while white will reflect it. Black will also ensure that the inside of the camera stays as dark as possible and does not ruin the film.

Photogram (2017) LS

During our Internal Investigation, we learned about the differences and similarities between reflection and refraction. Refraction describes light passing into a different medium and bending. Reflection is when light bounces off of surface. Based on these definitions, neither apply to my camera. The light in my camera is simply projected through the pinhole and onto the film. Another thing we learned about was whether light was a particle or a wave. According to our findings, light is both a particle and a wave depending on the situation. Since light can pass through another beam of light, it can be a wave. Since light can transfer energy when it hits a metal sheet, it can be a particle. In my camera, light behaves like a wave because of how it passes through the pinhole and onto the photosensitive paper.

Math Diagram (2017) LS

The diagram above describes the relationship between the object I photographed, the pinhole of my camera, and the distance between the pinhole and the paper. My object was 6.25 in tall, the height from ground to the pinhole is 5 in, and the distance from the pinhole to the film is 5.25 in. Using these three measurements and what I learned about similar triangles, I calculated the distance the light traveled from the object to the paper and the angles between the light and various parts of the camera. As shown above, the light rays pass from the right where the object is, to the left where the film is. This not only gives me a better understanding of the path of the light waves, but also applies the math concepts of trigonometry/geometry that we learn in class.