Tom gave us a very brief presentation on how a sterling engine works and what a Peltier junction is.  He had a few different experiments up and running to show us what each one did and its purpose of doing it.

The sterling engine is a heat engine that was invented in 1816 by Robert Stirling.  He explained how it has more efficient than a car engine, but it is only used for submarines and yachts, because of how quiet the engine is compared to a car engine.  It is a work in progress and is predicted to someday take over as the main engine used in almost everything.  One main difference on why the sterling engine is so different than a gas or diesel engine is that it does not have an exhaust, so no explosions take place which means the engine runs very quiet.  The engine also uses an external heat source which is usually powered by solar energy.  There are many ways to put together a sterling engine but this seems like the most simplistic way.

A Peltier Junction is a thermo-electric cooler and heater.  It consists of two ceramic plates, in which the peltier devides are connected to a DC current and voltage device.  Once connected, one side of the device gets cold while the other gets hot.  The side you need to use depends on what experiment or test you are running.  I am not sure which side Tom Vale used but I believe it is the cold side.  Tom used a fan running on water that was connected to the Peltier device.  The fan was powered because of the current that was going through the device and the water.

Overall, I thought he made a great presentation.  He also showed us an experiment with a bug zapper and a grill lighter.  Even though they were not as interesting as the first two, it was good to see what is possible.  Looking forward to the next lab and the field trip!

The solar cell lab we did last week asked us to measure the voltage output of the solar cell, and the light intensity output of the light sensor of the NXT. We started out by plugging in the the light source, then we had to connect the NXT to the battery and light source with a 2 sided wire.  The last step was to connect a usb cord from the battery to the computer so labview could give us all of our data.

We first started out by making the room as dark as possible, then reading the NXT without the light source on it.  This gave us a starting point on what to base our other calculations on.  The next step was to put a light source on the NXT at a few different distances.  We chose to measure the NXT distances of .5, 2, 3, and 5 inches away from the light source.  What we noticed was that the farther the NXT was away from the light source, the average voltage output decreased significantly.  The average voltage output with no light was about .07 and followed the distances with .60, .44, .39, and .30.  As you can see, there was almost no voltage output when there was no light on the NXT.  However, when light is applied, the average voltage more than tripled each time.

The next step was to shine light on a few colored film filters.  We kept the light 2 inches away from the filters so we could see how each color was affected.  Again, we averaged the voltage output of each color.  The primary blue film averaged a .45 voltage output whereas the iris purple film averaged .475 volts, followed by the yellow film averaging a .48 voltage.  These measurements told me that the film with the darkest color had the lowest average voltage output.  The blue film had the highest voltage output because it was a dark blue, followed by a lighter shade of purple, and ended with yellow which is not as dark of a color as blue or purple.

Overall, I thought it was a great lab to try and understand how the voltage output and light intensity output relate.  We noticed a pattern that the higher the light intensity output, the higher the average voltage output was.  In other words, the closer the light was to the NXT (or more light the NXT received), the voltage output would increase.  However, I noticed the average voltage output barely changed when the light was 2 inches away from the NXT, even with the colored films.  With just the light, the average voltage was .44, while the blue film was a .45 voltage, purple film a .475, and yellow film a .48.  This raises a question in our findings unless the films are not supposed to change the voltage by much.  In the end, I am confident with our measurements, and now understand the relationship between voltage output and light intensity output.

The other day we had an experiment on how different weights would affect the power, height, speed, acceleration, battery discharge, and time of our experiment.  These factors have a large influence in modern science and the lab proved that to me.

We first started off connecting weights to the pulley which told us all the information for the different segments of the lab.  Then, we had to connect the pulley to the battery so the battery can read all the information from the different runs we did for different weights.  The last thing we did to put the lab together was to connect the battery to the computer by a usb cord so the computer could relay the information from the battery on the screen.

We took down some data and found some interesting facts based on our results.    Whenever the mass of the weights decreased, the height, speed, and acceleration noticeably increased.  The height could have been my miscalculation by not stopping the power at the right time, but the other 2 were correct.  I believe this because When you take weight off of something running at the same power level (75%), it makes sense that the weights will accelerate faster every time, which also means it gets to the top of the pulley faster affecting the speed.

Another thing I noticed is that when the mass of the weights decreased, the time, MGH, and power all decreased as well.  I believe the calculations for time are correct because if you remove weights off the pulley at the same power level, it will rise to the top faster due to the speed of the pulley.  Also, I believe the MGH and power decreased because the less something weighs, the less energy/power it is going to use.

The last 2 topics to discuss are the gravity and battery discharge.  The gravity stayed the same at 9.8 because the pulley was the same height at all times.  However, the battery discharge scattered from 41 mV all the way up to 152 mV.  This leads me to believe that our calculations could have been a little off somewhere, however, everything else seems to make sense why it happened.

Summing it all up, it was an entertaining lab and I learned a few things i didn’t know before.  I could have guessed that the speed and acceleration would increase as the weight decreases but that is the only thing I really felt confident about.  It was a little confusing to figure out exactly what amount of weight was on there since I did not see any indications of the actual weight engraved on the weight itself.  Looking forward to the next energy lab and more ahead.  Buenos noches amigos.

Contagion started out by showing a few people becoming sick.  Their symptoms included severe headaches, cold symptoms, and difficulty swallowing.  On day 4 of the sickness, Matt Damon’s wife (Beth) dies.  He knew they were both sick but did not think it was that serious until his wife came home and started having a seizure on the kitchen floor.  Once she started foaming out of her mouth, he knew this was no normal sickness.  Mitch (Matt Damon) then went back to the hospital for further tests to make sure he was not sick, and got the notice that his wife had passed.  He begged to see her but was told it was not safe until his tests were done.  Once he was cleared to leave, on his way home, he got a call from the babysitter saying his son was sick and had a headache.  He rushed to the house but it was too late, he was dead with the same symptoms that his wife had.

Two days later, he went back to the hospital to get more tests, when his daughter from a previous marriage appears.  He tells her to go see her mother, concerned for her safety, but she insists she stays with him.  The next day, 3 nurses and 2 other children die at the school Mitch’s son attended and the school had to be shut down.  This was all over the news and now the world knows that a disease is spreading widely and very fast.  Then the doctors get the results of Beth’s autopsy that show traces of bat and pig DNA in her system, so the disease most likely came from an infected bat.  Mitch also learns that his wife’s flight had a lay over in Chicago in which she cheated on him and visited her x-husband.  Once Mitch found out that her x-husband was infected, he knew this was going to spread rapidly.

During the next few days, the CDC (Centers for Disease Control) tries to solve a cure for this disease.  One man, however, posts on his blog that he has the cure for the disease now called MEV-1 and shows how it worked for him.  He is saying the government is running a conspiracy against the world and made the disease themselves.  A couple weeks later, the news came on and said the government has found a cure for MEV-1 but will not be available in stores for 3 months.

After the 3 months pass, the government starts calling off random birthdays to receive the first vaccines.  Even though Mitch’s daughter does not get one the first day, they still have hope since she does not yet have symptoms of the virus.  In the meantime, Allen, who was the one that said he had a cure for the virus, gets his blood work back which shows that he was never effected by the virus.  The lead detective (Cheever) puts Allen in jail but he posts bail with the money he made from selling his vaccine.  Once Cheever gets his 2 vaccines for himself and his wife, he gives one to his wife then heads to the janitor’s house to give it to his son who has been sick.

The last day of the movie shows what Jody (Mitch’s daughter) has been waiting for.  She finds a box in her room and inside it is a note from her father telling her to be ready ay 8:00 with a dress.  She goes downstairs and the living room is set up as if it were prom night since she is not aloud to leave the house.  Then there is a knock on the door and it is her boyfriend Andy.  While they are dancing downstairs as if it was their prom, Mitch is upstairs looking for his camera.  He finds it, turns it on, and sees pictures of his wife Beth which makes him kneel down and start crying.  He goes downstairs and takes a picture of his daughter and her boyfriend while watching them dance.

Finally, the movie shows what caused this epidemic.  A construction company that Beth worked for was seen cutting down trees in China.  This caused bats to fly out of the trees, including the one who was first infected by the virus.  The bat is then seen dropping a banana that had its DNA on it into a pigs den.  A pig then goes on to eat the banana, and the pig eventually gets slaughtered at a meat factory.  A chef at the restaurant that Beth was at handled the pig, came out and posed for a picture with Beth while holding her hand, and that is what caused the global epidemic.

The movie Contagion helped opened my eyes on what could happen in the world today.  Not just that we should eat healthy/ watch what we eat, but also anything is possible.  Take care of what you can and let the rest fall into your hands.  It taught me that the average person touches their face at least 100 times a day, and if us individuals can limit that, things like this might happen a lot less.  Overall, be careful of what we eat/touch/smell etc… because now a days, anything can be harmful to us.