The field trip to California Science Center is a profound experience being of being a student. Compared to other field trips I attended, perhaps this is one among the most informative trip I had ever attended because it deals with common phenomena we experience today. Like sound perception, we know we are listening to sounds but we do not know the principles behind it, how does it work, and what are the things involved with it. In here I’ve learned that truly common knowledge has its own complex explanations.
Among them was the Energy Factor section where the food utilization was discussed by looking at light but informative explanations and good visuals making the knowledge employment process enjoyable. The space exploration section was another spot I will miss. I am passionate about how human beings search for answers especially by finding and exploring the outer space. Here enters the creativity and invention mechanisms of man that enables them to answer inquiries that boggle their minds like “is there life out there?
Is the world flat, how does space look like? ” Possibly this is the nearest physics related topic in the center aside from the sound and perception section. The technology of man encompassed all things possible to be seen and inquiries they want to answer, like the Mercury-Redstone 2 launched in Mercury to oversee the planet; satellites that encouraged man to have a clear view of what other planets look like such as Cassini-Huygens spacecraft that gave a clear photograph of Saturn. These kinds of invention are found in miniatures at the science center.
Well it really shows the purpose of why the science center was built- to kindle the curiosity and interests of students as well as other people towards learning crucial details about how things happen within their environment through pleasant visit in the science center (California Science Center, 2008) I must say the science center has some superb features. Among them was the biology section specifically at the cell laboratory where there were diverse pictures and microscopic experiences among tiny creatures that are indistinguishable to the eye which I was not able to see in a typical laboratory classes.
The most part that I had a lot of queries was the auditory section or the sound perception section where we were able to see how sound is created and perceived by human organs. Sound is by nature a stimulus that enables us to discriminate what we hear aside from vision, taste and smell and touch otherwise known as the five senses which we often used to exploit the things around us. Sound is by nature a wave existing in three kinds- mechanical, longitudinal, and pressure for it to be transported, it needs a media.
A media/medium is where the sound is travelling or interacting with. It is the channel where the means of transportation is taking place. Usually it is a particle-particle interaction in the air, water or solid media. The most common medium is the air. Thus, you have the power to send sound in all kinds of matter-solid, liquid, and gas (Henderson, 2007). However, sound does not travel in vacuum for the requirement should be a medium composed of matter. Since there is no matter in a vacuum, sound does not penetrate and travel through it.
In space, molecules and atoms are far apart so the spreading and travelling of sound would rather be negligible or in trace amounts. Like light waves, sound is characterized by the presence of amplitude, wavelength and frequency but the only difference is the medium where it is transmitted. Light can travel through vacuum for the discrete units of light are photons and quanta which are not matter in nature. The speed of sound differs in the medium they surpass (Kurtus, 2005). A sound is produced when vibrations coming from a source such as our vocal chords create a disturbance in the particles of the medium.
From the source, the vibration will cause the molecules to bump with neighboring molecules transferring the vibrations created by the source. This is characterized as the mechanical form of sound wave. One classic example usually demonstrated is the interaction of two tuning forks. When the first tuning fork vibrates, a few minutes later the second tuning fork receives the vibration coming from the source- the first tuning fork. This is caused by the transfer of vibration of air molecules with each other (Henderson, 2007). Sounds are generated whenever vibrations are generated in the medium where the sound travelled.
Vibrations cause the components of the medium to compress and pass the vibrations with each other in a parallel manner. The pressure from which the sound originated exerts a force to the neighboring molecules in a forward direction. This is longitudinal vibration. The other type is the pressure wave wherein different magnitudes of pressure is generated whenever producing a sound. Say for example the drum. When the drum is hit, it produces high pressure of vibrations. Eventually this pressure will cause a differential pressure gradient with the neighboring particles of the medium (Henderson, 2007).
Human ear is an extraordinary organ used to catch and collect sound. The architectural plan of the ear enables it to maximize the sound waves/vibrations that disperse through the medium (commonly air). The ear is composed of three major parts-the outer ear, middle ear and the inner ear. The funnel shape structure of the ear (pinna) serves as the sound catcher. The sound waves now travels up to the middle ear and finally the ear drum recognizes the sound waves and interprets it by making another vibrations that will enable the signal to be transferred to the cochlea.
The cochlea is a chamber that contains fluid and the vibrations will cause the fluid to exert a differential pressure so that the vibrations will be amplified. Secondary amplification of vibrations will be the job of the smallest bones of our body- the malleus, incus, and stapes. After the sound waves have been transformed to many tiny but amplified variations, it will now be detected by the hair cells beneath the organ of corti. The hair cells will then transmit the vibrations to the auditory nerves that can be perceived by the brain.
These complex steps take only for less than a second (Harris, 2008). The intensity of sound is measured by the degree of loudness through measuring its extent of compression. Usually it is quantified by the unit of decibel named after Alexander Graham Bell. Since sound is a wave thus, it possesses amplitude. The loudness of a sound is determined by the amplitude of the sound waves. As the waves spreads to the medium away from the source, the amplitude is diminishing and the loudness will be reduced.
Another factor is the absorptivity through different media. Some media are not able to spread the sound waves effectively resulting to a little sound dispersion. Since sound can only travel though medium which is made up of matter, the speed of sound is therefore slower than that of light. Sound travels in the air at a rate of 344 meters per second at 20-25? C. As the temperature and height of the source decreases, the speed of sound decreases. They show a direct relationship (Kurtus, 2005). There are two aspects affecting the speed of a sound.
First is the elastic property. It is defined as the mediums ability to retain its shape after the sound waves passes through it. Thus, the more intact the particles are, the more strength it has to maintain its shape. This is the reason why sound travels faster in liquids and solids than in gases when a longitudinal wave is applied. The second type is the inertial property. The inertial property of a sound is the inherent property of the medium to change its state of motion. Examples are the objects density, pressure and heat content.
While it is true that sound travels faster in solid media, it should also possess a lower density for the sound to travel faster. In general, sound passes through a medium more rapid if it is a solid with lower density (Henderson, 2007). All of these things awakened my curiosity on the sound perception during the visit to the California Science Center. Much more to it, it gave me enthusiasm to research more on the properties of sound. The giant ear in the museum showcased a lot of information for me to do this paper. References California Science Center (2008).
General information. Retrieved 18 July 21, 2008 from http://www. californiasciencecenter. org/GenInfo/GenInfo. php Henderson, T. (2007). The Nature of Sound Wave. The Physical Classroom Tutorial. Retrieved 18 July 21, 2008 from http://www. glenbrook. k12. il. us/GBSSCI/PHYS/CLASS/sound/u11l1a. html Kurtus, R. (26 June 2005). Sound Waves. School for Champions. Retrieved 18 July 21, 2008 from http://www. school-for-champions. com/science/sound. htm Harris, T. (2008). JHow Hearing Works. How Stuff works? Retrieved 18 July 21, 2008 from http://health. howstuffworks. com/hearing5. htm