Sarah Gibson

Our group chose to do an experiment on the Crooke Radiometer. A radiometer is actually an interesting scientific device that spins due to light and heat. It’s interesting because it uses something so simple, heat and light, and somehow the vanes move inside the radiometer. The scientific explanation behind this device is explained as heat energy. Within the vacuum, there contains four vanes with both a black and silver side to them. When light strikes these vanes, the black side of the vain will absorb more of the lights energy. When this occurs there is a temperature difference, which results in a formation of an air current, making the vanes move in a foreword direction.

We found out that people hypothesized that the higher the intensity of light the more RPMS or rotations per minute there are. In our experiment we wanted to test the theory of distance, light intensity, light color to see if there was a correlation to how fast the radiometer vanes spin. If the results we obtain are significantly influential, then we would make predictions of possible ways to form energy through the suns light with a moving turbine. To test the different theories we used a radiometer, a ruler, LED shake light (1 watt), 20 Watt Light, Sunlight, Flashlight(1.5 watts), different colored transparency paper and a Photogate Timer to measure the rotations.

Theory of Distance- we wanted to see if the distance of the light source made a difference in the radiometer rotations. We placed the radiometer on the base of the Photogate Timer and set it to pulse, which allowed us to get a reading on the rotations. We place the light source at different distances (0 in, 3in, 5in, 10in) and recorded our results to see if there was a correlation between distance and rotations.

Theory of Light Color- We wanted to see if there was a correlation between the color of light and the radiometer rotations. Once again we used the Photogate Timer to measure the rotations. We used four different colored transparencies (blue, red, yellow and green). We held the color sheet in front of our light source at a set distance of 0inches away from the radiometer and recorded our results.

Theory of Light intensity-We wanted to see if there was a relationship between the intensity of the light source and the spins of the radiometer. We used the Photogate Timer to record the rotations yet again. We used four different light sources (flashlight, LED flashlight, 20 watt light, Sunlight). We place the different light source at a set distance of 0inches away from the radiometer and recorded our results.

Results-We found that the distance of the light did affect the radiometer rotations; the closer the light the faster the vanes spun. We also found that there was a relationship between the color transparencies and the rotations of the radiometer. We aren’t sure of the reason, but the green transparency made the radiometer spin slower than the other three colors. Finally, we also found a strong correlation between the light intensity and the radiometer rotation speed. Natural sunlight made the radiometer spin the fastest. We also noticed the higher the wattage of the light, the faster the vanes spun. Below are graphs we constructed to show our results.

Overall, our presentation was an enjoyable experience. It was really interesting to teach something we created to a group of students. It seems that all of the students in the class were excited about the experiment topic. I feel that the class would have enjoyed using the radiometer themselves but that might be something to look forward to into the future. I also believe that the students would take away more from our project if they were connected to a computer in order to effectively see the table of results. Overall it was a great learning experience for everyone

Last class we also did a solar lab with our robots. We were given a light source and a solar pannel, which was hooked up to our robot. We were supposed to hold the solar pannel near the light at different distances to see how much solar energy was produced.

We first held got a base reading on the solar panel without it being near any light. We then proveeded with our experiment and held it 1cm away from the light, 6cm and 25cm. A chart of the data we collected is below.

When there was no light on the solar pannel (0cm) you can see that the energy was negative, obviously solar pannels need light to produce anything.As you can see, the closer the solar pannel was to the light the more energy it produced.

For our next experiment we introduced color. We were given four colored plastic sheets to hold over the light to see how that affected the solar pannel. Our data collected is below.

The chart with all of four colors is not very linear, it’s kind of all over the place. To get a better idea of the effects of the colors I wanted to compate the lightest color and the darkest color we used to see the difference. In the chart to the right I compared light blue with a dark purple. You can see that the light blue color produced more energy than the purple, which makes sense because more light can shine through lighter colors.

Last class we used something new with our robots. We were given a burner, thermometer probes and a beaker of water and a beaker with oil. In the lab we were supposed to heat up the liquids and observe which liquid absorbed the heat energy the quickest. To do that our robots were hooked up to the two probes, which were used to measure the temperature. We first measured the temperature of the liquids without any heat to get a base temperature. We then put the beakers on the burner, placed the probes in the liquid (making sure not to let it touch the glass), and let the program run its course.

Below you can see our results from the lab.

In our lab the temperature change was not what we expected. The oil is supposed to have the highest temperature change, but that was not the case. We also had to calculate the energy absorbed by both liquids, and for our experiment the water absorbed more energy. That was also unexpected, because the oil is supposed to absorb the most energy.

Change in Water	Change in oil	Energy Absorbed by Water	Energy Absorbed by Oil
4.146799	3.614559	1388.016561	532.0630848

We are not sure why our experiment didn’t work out the way it was supposed to. The oil was a higher temperature than the water though, which was supposed to happen, but our other data was off and we really don’t know why. Our probes did not touch the glass, and both beakers were put on the burner at the same time.

Last class we played with our robots again, but this time it was a little different. We were given a shake flashlight to hook up to our robot, which would record the voltage produced when the flashlight was shaken. I thought it was a pretty interesting experiment.

Our first run we left the flashlight alone to record its “base line”, which is how much voltage it produces when it’s not moving. Our second run we shook it fairly slowly; we shook it 49 times. We gradually increased the speed/amount of shakes, which was supposed to increase the voltage produced. Our  third run we shook it 74 times, and on our last run we shook it 110 times. Our results are shown below. As you can see from our data below, the more shakes the higher the voltage.

Last class we had another interesting demonstration from Tom, this time he brought in a Telsa coil. A Tesla coil is pretty old technology, from the 1890’s. It’s basically an electrical circuit that can transfer energy wireless. The Tesla coil he brought in looks similar to the one below, not quite but they are all basically constructed the same way.

The hopes behind this technology was that it could one day power homes, so there would be no need for outlets because the energy needed to power items could be transmitted wirelessly. Obviously we know that that didn’t quite work out. The energy is still being transferred, but it interferes with things like pacemakers, so it is not particle to use in everyday life.

Even though it can’t be used to power houses, Tesla coils are still pretty cool and interesting to look at. Tom showed us that light bulbs can light up when held near the Tesla coil. It also gives off sparks, which are pretty intimidating, but they are harmless. The larger the Tesla coil, the larger the sparks; some are taller than the average man and shoot sparks over 100 feet long! He also held a pole to the spark, and you would think that it would shock him, but the energy just flows right around and into the ground. Another interesting thing he showed us was that if you balance a paperclip on the tip it will spin, which basically creates a little motor.

Although the technology didn’t live up to its hopes, it’s still pretty cool.

 

 

 

Last class we went on a field trip to MIT to see their nuclear fusion lab. 85% of the worlds energy comes from fossil fuels, which when converted into energy are damaging to the environment and aren’t renewable so eventually we will run out of fossil fuels. The hunt for a better energy source is ongoing, but a lot of people think nuclear fusion is the answer. Nuclear fusion has no waste, can be done basically anywhere and has no possibility of a meltdown unlike nuclear fission. So what’s the problem? Well it’s very complicated and costly. Scientists around the world have been working on ironing out the fusion problems, but they still aren’t there yet. There has been a lot of progress though, which is what we saw at MIT.

When we got there we had a little energy 101 lesson, which turned into a more in depth nuclear fission lesson which made my head spin. I am not really a science person, but it amazed me how knowledgeable they were and how people could figure something like that out. It is such a complicated process, and I am still amazed at how people could even think of doing it, let alone making it actually happen. After the lesson we went into their lab, which was pretty much what you would expect from a scientific research lab. There were rows and rows of computers. The most surprising thing was how old some of their technology was; they had telephones from the 90’s and some of their computers were pretty ancient too.

After looking at their lab we went into where their nuclear fusion reactor is. It was really loud inside, and it didn’t look at all how I thought it would. Our tour guide said that they run the reactor a few times a day, but only for a second or so. A few years ago they were only able to run it for fractions of a second, so that shows you they are advancing. I was pretty surprised at how much energy they are using in their reactor lab. He said they use so much energy that sometimes the power companies have to call them and tell them not to run because it may cause a blackout because the energy companies cannot keep up. They are trying to crack the energy problem, but they are using an awful lot themselves to solve it.

They may be advancing and getting closer, but it seems like nuclear fusion is still far from solving the worlds energy crisis.

For this lab we set up a pulley system with weights that our robot controlled. We analyzed how changes in factors effected our data.

The first thing we analyzed was the relation between mass and acceleration. As you can see there was a strong correlation between the two; as we decreased the mass the acceleration increase. The more weights we took off, the faster it accelerated, which makes sense.

We also analyzed acceleration and power levels. We found that the two variables have a strong correlation; the higher the power level, the higher the acceleration.

We also analyzed power used vs. power level. For this comparison, the mass was a constant .25kg, and we changed the power level to see how if affected the power used. As the power used increased, the power level decreased. The more power we used, the lower power level got, which also makes sense.

The last things we examined  were power used and percentage power level. This comparison was a little different than the others, it took some computations in excel to get to our answer. Again, there was a strong correlation between the amount of power used to the percentage power level. When power used is increased, the percentage power level also increases.

Demand response manages customer’s consumption of electricity, to help control and stabilize supply conditions. As you can see from the chart below, there are peaks in energy consumption throughout the day when energy is demanded the most. Peaks are especially high in certain month, such as summer, when consumers are using energy sucking appliances like air conditioners. Demand response also helps prevent outages or blackouts, which is a result of the demand being too high to meet. Basic economics will tell you that as demand increases, price increases; the same goes for energy consumption. At the peaks of consumption, consumers are actually paying more for their energy than they would at off peak times. If used correctly, demand response can significantly decrease the peaks in consumption, which lowers the price for consumers.

It’s really as simple as turning off a light when it isn’t needed, but demand response can be taken much farther. With today’s technology, it is easier for consumers to manage their energy use and use demand response to their advantage. There are many “smart” appliances that actually help consumers respond to demand without much effort. Appliances such as dishwashers and washing machines can actually be programmed on a timer so consumers can manage their energy use. Instead of using appliances on peak hours, consumers can program their appliances to run at off peak hours, which not only cuts down their costs but also helps the demand of energy consumption. Newer air conditioners are also made to make it easy for consumers to respond to energy demand. Instead of having the AC run all day, it’s easy to program your air conditioner to turn off once your room reaches a certain temperature, which cuts down the demand in the summer time. Pre-cooling buildings on off peak times also help lower demand. For the really tech-savvy people out there, you can actually make your house a “smart house” and have the ability to control every appliance with the click of a finger, which makes it incredibly easy to cut back your electricity consumption.

Responding to demand is fairly simple. Although we do have all of this technology out there that makes it easier, it’s just an added convenience and isn’t really needed to make a difference. Like I said before, it’s as easy as flipping off a light switch.

 

 

Last week Mr. Vale came in and presented to the class. He showed up a peltier device, a stirling engine, an electric bug zapper and a solar motor. I might just be a closet science nerd, but I was genuinely interested and fascinated by everything he showed us. He mentioned how most of the things he showed us were fairly old technologies that has been around for a while (the peltier device and the stirling engine being the oldest). It really amazed me how some of the things worked. The peltier device basically runs off of the polarity of metal and water. The solar motor was also really neat because it was floating and actually spun pretty fast. I though the stirling engine was also really cool because it runs off of the steam of hot water, which is something that is readily available. It made me wonder if this technology is so old then why isn’t it being applied more often? It may not be as efficient and produce as much energy as other sources, but I think it should be used and combined with other sources to help support our energy needs in a sustainable manner.

stirling engine:

solar motor: 

Last week in class we built and programmed the lego robots. I thought the lab was fun and a good break from the typical lecture style class most of us have to sit though all day. My partner and I built the robot fairly easily, and we successful in programming it to go forwards, backwards and to make sounds. We also got our robot to go in a 1/2 meter circle with some trial and error. Overall I thought the lab was really interesting. It definitely made me think how difficult and time consuming it must be to build a real robot and program it to do specific things, because it took us two class periods and a ton of trial and error just to put together a simple lego robot. If we could program our little lego robot to do the simple movements and commands, I can only imagine the abilities experts have, I am sure the possibilities are almost endless.