KristinK

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__Reflections__

 * ==Reflection on Wiki; 8/28/09== ||
 * 1) I've never used a wikispace, but I had two blogs last year: one for English and one for French. I didn't use the English one a lot, but I used the French one a lot. There pretty simple to navigate.

2) I have unlimited internet access at home. I have a laptop and wireless internent access so getting online is never a problem.

3) I believe the wikispace will help a lot as a tool outside of class. There will never be an excuse for forgetting an assignment. The links will also be helpful if there's ever any confusion on homework, or a lab. ||


 * Reflection on The Scientific Method; 8/30/09 **

This author believes that "science is not a catalog of answers, but rather a process for conducting an ongoing dialog."(Pg. 4) The scientific method is a series of observations, identifying patterns, hypotheses and predictions. The author believes that it is very important, in science, "to look around us and see what's there."(Pg. 5) That would be the observations, just looking at nature without changing it. The author believes it is okay to not make observations, but it would not be a method of science.

Identifying patterns is another step in the scientific method. That would be using our observations and recognizing a pattern and taking a quantative measurement. At this point a scientist would make some sort of chart or graph. The author insists that, though complicated, math is far more exact and concise when figuring outcomes and measurements.

Another step in the scientific method is forming a hypothesis, a tentative educated guess. Forming many hypotheses help to justify laws and theories and then test those laws and theories. Prediction and testing is another step. It is "how a particular system will behave, then observing nature to see if the system behaves as predicted." (Pg.6) This step does not prove or disprove a hypothesis it just defines the hypothesis' range. This helps to turn the hypothesis into a more general law or theory; such as: Newton's laws of motion, theory of gravitation, law of universal gravitation, etc...The author re-enforces "every law and theory is subject to change, based on new observations." (Pg.7) Basically, there is always some way a statement can be false.

The author feels that the scientific method is a never ending cycle: every theory will lead to a new hypothesis which will lead to a new observation. The author insists that the scientific method is not a "rigid cookbook," it is very creative and does not always need to go in a specific order. A hypothesis can come before an observation, for example. The author understands that the scientific method is a system that connects all branches of science no matter how macro or micro.

​ ​**Reflection on Scientific Method by Percy Bridgam; 9/1/09**

In complete contrast to the last author Dr. Bridgman completely reject the idea of one single scientific method. He says, "No working scientist [...] asks himself whether he is being properly scientific, nor is he interested in any method he may be using." Scientists are too interested in getting into the actual experiments and science to be concerned in a specific scientific method. He believes the scientific method is something made up by observers of science that are trying to understand and find consistencies then generalize the different processes. Dr. Bridgman believes that these generalities are obvious and something a scientist doesn't need to waste time thinking about.

He does believe; however, that scientists all have common objectives: to get the right answer, verify the right answer, check others' answers and have no preconceptions. The previous author believed less in the idea of right and wrong and more in the idea of finding new answers to make science more accurate. If you try, at least in science, to be right all the time you will exhaust yourself pretty quickly. There is always something else that can prove your idea wrong; which is why verification of your answers is important. You can get the right answer a million times, but according to Dr. Bridgman is only takes one exception to make you wrong. The previous author would say that this is helpful in that it better defines the hypothesis, law, or theory. One thing both articles had in common is the idea that a scientist can hold no preconception. You can't get your hopes up that one answer will be right. You have to be open to change.

According to Dr. Bridgman no scientist is "consciously following and prescribed course" and that a scientific method is something the individual scientist creates for them self. I have trouble believing that there is no scientific method. The scientific method is something so broad, how could it not incorporate a piece of each scientist’s process? Doesn't, even a scientist; need some sort of common ground to begin their experiments? For, a physicist who believes so strongly in the verification of "the right answer" shouldn't he see there needs to be some sort of method scientists' can turn to for accurate verifications and explanations of each new discovery. Now I'm no Nobel Peace Prize winner, nor have I written greatly on the scientific method, but as an outsider I find some flaws in Dr. Bridgman’s thinking.


 * Simple Harmonic Motion Lab: Independent Reflection: **


 * Independent reflection:** One lab report will be turned in for each group. In addition, each student must complete //independently// a reflection addressing the following questions:
 * How was the process of designing and testing a clock similar to the scientific method as discussed in class? Well, we used most of the steps in the scientific method in the lab. We started with our preconceptions, or how we thought we would design our clocks. Then our group came up with a hypothesis on what we thought would happen to the clock, making predictions. That lead us to our experiments where we recorded our data and made the necessary changes, to weights and lengths. We found facts through patterns, for example, if you add more weight to the spring the faster it goes.
 * How did it differ? Well, we didn't discover any groundbreaking theories or laws, but all the steps were included somewhere in our process.
 * What "steps" in the scientific process were present and which were missing? Most of the steps were present, like preconceptions, hypothesis, predictions, patterns, experiments, observations, data and facts. We did not collect enough data to create a law, nor did we discover a theory.
 * Was there a part of the activity that is not a part of the scientific process? I don't think so. I think everything we did could have been described under some part of the scientific method. There was, however, a lot of trial and error, which I guess is part of the experiment, observation steps, but it's not a specific step in the method.

**Systems Reflection: 9/20/09****:**

Read the sections on systems. Read the sections on momentum and conservation of momentum What is a system according to physicists? How is this definition different from your definition (your original definition)? What does the concept of "closed" or "isolated" system have to do with conservation of mass? What about conservation of momentum?

According to physicists a system is: "any object, or set of objects that we wish to consider. Everything else in the universe we will reference as its 'environment' or the surroundings.'" My original definition for a system was: something that encompasses many different things and can work within its self. These definitions are very different. I thought of a system as something large (like the ecosystem, or weather systems), when actually a system can be something as minuscule as a box of nails, it can be whatever we want it to be.

A closed or isolated system is a system where "no mass enters or leaves (but energy may be exchanged with the environment." A closed system is the only place where the conservation of mass holds. The conservation of mass says, no matter can be created or destroyed. Now, in a closed system this is true, like when you burn a piece of paper is a closed jar, even after it's burned it weighs the same it is just the energy that is exchanged within the system. If you did the same experiment in an open system mass could be lost, or gained through any number of variables.

An isolated system in relation to momentum would be "one which experiences no net force from outside the system." Like the example given with the two dry-ice pucks on a table, there is very low friction and the effects of the table and the earth nearly balance each other out. It's not perfectly balanced, but sometimes the unbalanced forces are small enough to ignore. When using conservation of momentum it is much more accurate to use smaller systems, so the unbalanced forces and variables are smaller. That way there is more accuracy.

**Work Reflection: 9/27/09**

Well, work is the quantity of force times distance. It is the application of force and the movement of something by that force. It can be expressed by forcing something to move against an opposing force, or when speed is changed. Potential energy (PE) is stored energy that has potential to do work. For example and stretched or compressed spring has potential for doing work. It is the energy of position. Kinetic energy (KE) is the energy of motion, it is moving and capable of doing work. Kinetic energy can be expressed as thermal energy, acoustical energy, and radiant energy.
 * How are work, KE, PE, and the law of conservation of energy related? Pay specific attention to the concept of work.**

The conservation of energy states that energy cannot be created or destroyed. It can be transformed from one form into another, but the total amount of energy never changes. You can see this in relation to work if you look at the example, when using a slingshot you draw back a rock work is done by stretching the rubber band, giving the rubber band potential energy. After it's released the rock has kinetic energy (it is moving) that is almost equal to the potential energy. The energy not expressed as kinetic is expressed by heat. The rock and whatever you throw the rock at are warmer than the slingshot. Still, energy is transformed without loss or gain. The fact energy can be conserved and transformed (as see through potential to kinetic energy) allows you to measure the amount of work an object can perform. The more potential energy you have the more kinetic energy you will get allowing you to do more work.

**Kinetic Energy, Heat, and Temperature Reflection: 10/3/09**

Read sections 21-1, 21-2, 21-4, 21-5, 21-6 in your handout. Temperature is how hot or cold something is compared with a standard. It is measured using the idea that most matter expands when the temperature is increased, that is how a thermometer measure temperature. Temperature is associated with “the random motions of molecules in a substance.” Since kinetic energy is the energy of motion then temperature is relative to the average kinetic energy of molecular translational motion, or motion along a path. It is like when you touch something warm and you feel the heat; that is kinetic energy transferred by the molecules of the warm surface to the molecules in your hand. Solids and liquids however, have molecules that are more confined. Those molecules have potential energy.
 * Directions:**
 * Describe the relationship between kinetic energy, heat, and temperature.**

When you touch something hot, like a cup of tea, energy is transferred to your hand, but when you touch something cold, like snow, your hand transfers energy to the snow. This shows that “the direction of spontaneous energy transfer is always from a warmer to a cooler substance.” The energy that is transferred because of temperature change is called heat. Matter though does not contain heat, it contains forms of energy. Heat is called “energy in transit” meaning it moves between two objects. After it is transferred it is no longer heat, it is thermal energy (showing the relationship between heat and temperature.) It can also be called internal energy. Heat flowing from one object touching another is thermal contact. This means that heat will not flow from an object with more total molecular kinetic energy to one with less. Heat flow according to the difference in temperature (average kinetic energy.)

There are other forms of kinetic energy, with respect to internal energy. One is rotational kinetic energy, the energy from the internal movement of atoms within the molecules. There is also potential energy from forces between molecules known as internal energy. These energies are not heat, but they can be changed by heat. Also, a substance, like ice, can absorb heat without changing the temperature. It just changes phases. Temperature change depends on more than mass. It depends on mass and the kind of substance affected. The unit of heat is the heat necessary to produce some standard, agreed on temperature change for a specified mass of material. It is measured in calories, or kilocalories (1000calories) sometimes just called a Calorie. That is how the energy value of food is measured, by burning food and measuring heat released.

Energy absorbed by a substance can have varying affects. It can increase speed of molecules which can lead to a temperature increase, increase rotation, internal vibration, stretch intermolecular bonds, and be stored as potential energy. This is not a measure of temperature though, because temperature is the measure of kinetic energy, which is only part of absorbed energy. Specific heat capacity is the amount of heat a substance can absorb and the energy is stores. This why it takes less energy to heat iron than water, the water can absorb more heat and have the same increase in energy.

**Energy Reflection: 10/11/09**

The two rules of energy are: //energy is conserved// and //energy always goes from more useful to less useful forms//.
 * Think about how the two "rules" of energy apply to your labs; collisions of carts, mechanical equivalent of heat, energy on a ramp, roller coaster, and calorimetry.**


 * Collisions of Carts:** This lab showed both the laws of thermodynamics. We saw the first law of thermodynamics when the cars collided, and energy was conserved. When the cars hit we saw work being done, there was force from one car being used to move the other car. This means that energy wasn’t created or destroyed it was just shifted from one form to another. We saw the second law of thermodynamics when we heard the cars colliding. Sound is a type of kinetic energy, so energy was conserved, but that energy was not useful. It couldn’t do work and energy was lost. That’s an example of how energy always goes from more useful to less useful.


 * Mechanical Equivalent of Heat:** The whole concept of mechanical equivalent of heat is that motion and heat are interchangeable; a certain amount of work can generate the same amount of heat. It is basically the first law of thermodynamics.


 * Energy on a Ramp:** This lab showed the transfer of energy from potential to kinetic. When the car or ball was started higher on the ramp it went faster, it had the potential to gain more kinetic energy. It’s another example of conservation of energy. We noticed with the ball that when rolled next to the cart it moved slower. It was an example of how heat goes from more useful to less useful. The ball was having more energy being transferred to rotational kinetic energy forcing the ball to go slower.


 * Roller Coaster:** The roller coaster lab was a very good example of how energy shifts from one form to another (the first law of thermodynamics). When the roller coaster cart was being pulled up by the motor electrical energy is converted to gravitational potential energy. Then, when the car goes down the potential energy is converted to kinetic energy. Then it comes to a stop and the cycle continues. This lab also showed us how energy always goes from more useful to less useful. The friction between the cart and the roller coaster track was energy being converted to heat, which provided no use to the roller coaster. The fact the roller coaster relied on a motor (to move it to the top) caused another variable. The second law says “no engine can operate on 100percent efficiency.” That means the parts moving in the motor lost energy as frictional heat.


 * Calorimetry:** This lab showed us another part of the first law of thermodynamics: how energy can be moved from one place to another. When we would put a hot metal, or paraffin in the room temperature water energy of heat was transferred from the object to the calorimeter. This heat was shown by a temperature increase. The lab also showed heat energy going from hot to cold (part of the second law). Even though the water gained heat in the experiment the metal and paraffin lost heat. The fact that the calorimeter and stirrer also gained heat (not just the water) added another variable. That energy made it more difficult for us to measure the specific heat; therefore, the energy was less useful.

**Calorimetry Lab Reflection 10/13/09**


 * You measured heat of fusion either by heating paraffin until it melted or by cooling hot paraffin until it solidified. Describe the opposite process for measuring the heat of fusion. What advantages and disadvantages would this other technique have?**

We cooled hot paraffin until it solidified, so we took liquid paraffin, put it in the calorimeter and measured the temperature change of the water and paraffin. If we had heated it until it melted we would have had to measure the paraffin at room temperature and then the temperature at which it melted, so the paraffin would have a temperature gain not loss. They would both go through the change of state at the same temperature though. One advantage of melting the paraffin would be that we would start at room temperature so we wouldn't have to worry about losing heat bring melted paraffin to the calorimeter (a problem we had in the other lab). However, it would be hard to keep a closed system, I don' t think you could use the calorimeter to heat the wax. If you just had it boiling in the open there would be too many ways for heat to be lost.

Megan and Kristin's Calorimetry Lab

**Projectile Motion Reflection 11/1/09**

How does the horizontal speed of a projectile affect the time to hit the ground? How does it affect the distance the projectile travels? How does the vertical speed of a projectile affect the time to hit the ground? How does it affect the distance the projectile travels?**
 * How does the height of firing of a projectile affect the time to hit the ground? How does it affect the distance the projectile travels?

The height a projectile is fired does not affect the time it takes to hit the ground. This has to do with the fact that horizontal speed doesn’t affect vertical speed. Even though the object is shot from an angle that means it can build up more speed on its vertical drop. The higher a projectile is fired the greater distance it will go, like when you shoot an arrow at an angle it will go farther than if you just shoot it straight.

Horizontal speed does affect the time it takes for the projectile to hit the ground. The greater the horizontal speed the farther the object will travel. This is because horizontal speed deals directly with the horizontal distance, or position the object travels. Like with the basketball video we watched, the height of the ball had no affect on horizontal speed, or position. Only the distance the ball travelled affected the horizontal aspects.

The vertical speed determines the amount of time it takes for the projectile to hit the ground. Just like the horizontal speed had no affect on the height, the vertical speed has no affect on the distance the projectile travels. Vertical position and velocity deal directly with the up and down motion and velocity increase and decrease, not the distance the object will travel.

**Scientific Imagination Reflection 12/15/09**

What do electric and magnetic fields look like? Apparently that's unknown, so how does a person imagine the electric and magnetic fields? There's no real answer for that either, there are no pictures or stories that can make them visible. A person could take a mathematical view, which involves having six numbers associated with every point in space –not exactly appealing to the eyes. Maybe temperature would be a more appropriate tool? Like imagining the world in jello, or ether. That ended up just standing in the way of progress.

So what's to be done when we're "limited to abstractions"? The fields are real, because instruments can detect them and learn about galaxies a billion miles away. This is when a scientist is forced to use scientific imagination, which isn't as easy as just believing whatever you think. A scientist is only allowed to imagine concepts that are consistent with everything else they know. It's a sort of restricted imagination that makes the idea of finding something new quite difficult.

Scientific imagination isn't for everyone. I couldn't see myself looking at a de-colored rainbow and saying "Ooh, that's beautiful," interesting, fun (maybe), but beautiful, I'm not so sure. I guess intellectual beauty is in the eye of the beholder.

**Agents of Climate: Earth System Budgets Reflection 1/7/10**

Recently we've been discussing the greenhouse effect, which is directly related to climate. Climate is a series of atmospheric pressure (i.e. temperature, humidity and precipitation). Climate behavior reflects the conditions and motions of the atmosphere. Electromagnetic radiation (a stream of photons) from the sun is one underlying force that explains all these patterns. Climate is the result of solar radiation's reaction with atmospheric gases (methane, carbon dioxide, water vapor, nitrous oxide and ozone). Each gas absorbs different wavelengths of waves. An increase or decrease to any one of these gases can cause climate change. For example, a decrease in ozone concentration leads to an increase in the ability of energetic radiation to reach the Earth's surface. The solar radiation that is not absorbed by these gases (about half) heats the Earth; the Earth also emits radiation (infrared photons) into the atmosphere, but at much longer wavelengths than the sun. Greenhouse gases most commonly emitted by man are: methane, nitrous oxide and chlorofluorocarbons (although I believe commercial use of CFCs are illegal now). Ultimately the use of these gases causes the Earth's surface temperature to increase.

The relationship between the radiation process and climate can be described in almost the same way as a financial budget. If income (radiation) and expense (climate) are equal than the budget is balanced. If there's more income than expense then you have a profit, but if you spend more than you make then you lose money. Although, it is impossible to tell if all the input and output processes have been discovered, or if their true magnitude has been defined. The example the article uses is that of a tub receiving water from several faucets. If all the water is added or taken away at the same rate than the level is constant, but when the water has waves and the rates vary it's hard to see how things are changing, or if they are in fact balanced. You can however measure the rate of supply from each "faucet" and the removal by each "drain," or the "pool size" and either supply or removal. That is known as an Earth system budget analysis.

There are some questions that come along with this analysis such as,what would happen if more water started coming out of one faucet? Will the water level keep rising? This all depends on the drains ability to handle the additional flow. If it can't than the water would rise and some new equilibrium would have to be reached. The same is true if the outflow of the drain increased. All these situations occur in an Earth system budget. One concept of the budget is the reservoir (an entity with physical, chemical and biological properties uniformly distributed) like our atmosphere. There's also flux, the amount of specific material moving from one reservoir to another over a period of time (like the flow of solar energy, or the evaporation of water). Then there are sources and sinks, the rates of creation or destruction (like the photochemical production and destruction of ozone). All these concepts together create a cycle. Knowing any two concepts allows you to figure out the third. Although every species has several sources and sinks and each must be studied individually.

About 47% of incoming solar radiation warms the Earth. The rest gets returned to space, reflected by clouds, particles, or the Earth. Half of the 47% absorbed is turned into latent heat and absorbed by water. Other surface energy goes back to the atmosphere, or is absorbed by greenhouse gases. Only a net 18% is lost to space by radiation. This cycle of energy between the atmosphere and the Earth's surface is the greenhouse effect (without it the Earth would be about 33°C cooler). The Earth system budget is 200% in balance. The Earth stays in balance by adjusting its temperature (which is how climate change occurs). The stability of the climate depends on the stability of the Sun's radiant energy flux and on the stability of energy absorption and emission in the atmosphere. Climate for a given area is also determined by it position as it rotates around the sun and its spacial lay-out. These factors effect atmospheric and ocean movement. This with heat transfer produce atmospheric circulation. This is why it's so much warmer near the equator and cooler near the poles.

**Greenhouse Effect Lab: Part III 1/11/10**

1. How does the "greenhouse effect" affect temperature on the Earth? 2. How is the "greenhouse effect" similar to blankets on a bed? 3. Is the "greenhouse effect" good or bad for the Earth?**
 * Write a paragraph that answers the following questions:

The greenhouse effect warms the Earth by trapping solar radiation (infrared photons) that come from the sun. The sun releases photons of light (solar photons) that stream towards the Earth and enter the atmosphere, these photons pass right through greenhouse gases (water, carbon dioxide, methane and nitrous oxide). Once they hit the Earth they bounce and stream away from the Earth in the form of infrared photons (these have less energy than light). These infrared photons get absorbed by greenhouse gases and are re-emitted towards the Earth, increasing Earth's temperature. The greenhouse effect is like a blanket, insomuch as it traps heat (infrared photons) and keeps you, or the Earth, warm. Also, the more blankets you add the hotter you get, because less heat is able to slip through the spaces in the blanket, or the chemicals in the atmosphere. This is what we saw happen when we added glass panes in our simulation. The Earth's temperature went up drastically. The greenhouse effect is good for the Earth. Without it, as we saw in Part I (number ten) without the greenhouse effect, or glass panes, the Earth's temperature would be and average of -2°F. These temperature would be uninhabitable for most plants and animals. Without the greenhouse effect man probably wouldn't exist, at least not like we do now. However, it's always best to have everything in moderation. As we saw when we added multiple glass panes the Earth's temperature went up to 120°F, again uninhabitable for most living things. Overall the greenhouse effect is essential for the Earth, or at least mans survival, so I'm all for it!

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