Forensic lab #2

1. What scientific ideas or theories would help you explain why you are able to use the procedures to analyze evidence?

In all of the labs there has been scientific ideas and theories that explained why the procedures we used to analyze the evidence worked. However for most of the scientific ideas I had no idea why it worked. For example In the "Ink is still wet" lab the alcohol made the ink grow and separate yet I had no idea why the alcohol caused separation. In the "Killer Coffee" lab as well as the "Ink is still wet" lab we used a colorimeter to determine the absorption. The colorimeter was another procedure we did that I wasn't sure how it calculated the absorption.

2. How has your approach to lab procedures changed from the first round of labs? Are you more/less confident in your results?

I realized during these labs how vital reading the directions closely is. For this round of labs I went to the labs more clear and confident on what I was doing. Since I was more comfortable in the steps I took during the lab I was more confident in my results. I was also more comfortable with the procedures or tools I used during the second round labs. Since this was my second round of labs I had less questions about the tools used and more experience using them.

Multiple observations and experiments will help us create more accurate inferences. By having more data we have more evidence to back up our inferences. When we were doing the fiber case recorded three drawings of one fiber so we could have more evidence to back up our inference. In the soil lab we tested the conductivity the Ph and the water absorption for each soil in order to prove our conclusion. In the firearms we measured the grooves, lands, weight etc so we could have more observations to use as evidence. This is an example of how the more observations and trials you have the more accurate your conclusion will be in each case.

It was hard to be completely precise in all of the labs. By adding a human variable to an experiment it's impossible to always be precise. Therefore it's hard to be confident about results when you're not sure if it's completely precise. In order to be confident about your results you need to do multiple test and trials to be completely back up your conclusion. For example in the fibers lab you do three drawing of each fiber just in case one of the recordings in wasn't completely precise. In the firearm lab it was also hard to be completely precise. Sometimes it was unclear which were the grooves and which were the lands. However, you can rely on making multiple observations and trials to completely and accurately prove your answer.

You can rely on "known" data to match up with your own when you want to prove your conclusion. For example in the caliber lab you had a chart that you could compare your measurements with in order to find where the bullets came from and also whether your measurements where accurate. It was clear that this information reliable because it wasn't just an inference it was scientific. The caliber lab was the only lab that you could rely on "known" data to match up with. On the other labs you had to generate you own data to compare with the crime scene data. You had to generate this data because it’s different for each crime scene. Unlike the calibers lab there isn’t recorded data you can use.

Blood splatter lab 1

By dropping multiple drops at each height we could create a more accurate diameter of a drop by finding the average. If we just did one trial then we can't be sure that was the most accurate drop. I think for the most part the diameter increased as you went up in height. The data was sometimes a little random, but in most groups their largest diameter was in the highest height. I think I could have a good idea about how high height at which a blood drop originated based on the diameter. However, I don't know how accurate or precise it would be because the diameters of different group's drop differed. The drops weren't exactly the same diameter at the same height some weren't even close to others.

Sound of Science

A thunderous flapping sound filled the sky. The villagers peeked out of their huts shielding the sun from their eyes. They gasped in wonder as the sky turned black. Hundreds of birds exited the forest, shrieking in warning and confusion. Smoke began to emerge from the forest lingering in the sky.

A murmur went through the crowd naming the obvious. “I can’t say I’m surprised. These forest fires have been occurring all summer,” said one villager.

“I suppose we’ll just have to wait it out,” said another.

` A young boy was the only one voice what they were all thinking, “ What if it spreads to our village?” The villagers froze at the question and no one spoke a word for a few seconds.

Finally one of the older villagers said wearily, “The boy’s right. Look how big the fires has gotten already.” The fire had gotten a great deal bigger. It greedily snatched up anything in its way, soon beginning to feast on trees, letting out crackles of glee. “We must pack up our most valuable possessions and escape this fire,” said the same villager solemnly.

The villagers anxiously glance at the fire and each other before reluctantly following the villager’s directions. Once they packed the essentials and food for a couple of days they headed out. The villagers took one last regretful look at their village, wondering if they would ever see it again.

The village hiked all day, miserably tromping through the tall grass away from their only home. Once the sun began to set the villagers laid out bed rolls and after a light dinner went into a restless sleep.

The next morning the villagers were woken up by a loud motor sound. They looked up towards the sound and spied a plane flying over their heads straight towards their village. After much discussion they headed back to their village to see if the plane had anything to do with the fire. By the time they reached their village the sun was beginning to set. Despite the lack of light the villagers could see clearly that the plane was gone and the fire was out. At least half of their village was destroyed, but they were too relieved the fire was gone to care.