AccSci Module 5 Notes PDF

The Scientific Method: Four main problems are very linear, not intuitive, facts vs process and focused on experiment Peptic Ulcers: Hypothesis o Peptic ulcers were caused by a bacterium called Heliobacter Pylori. Method o They wanted to investigate...

The Scientific Method: Four main problems are very linear, not intuitive, facts vs process and focused on experiment Peptic Ulcers: Hypothesis o Peptic ulcers were caused by a bacterium called Heliobacter Pylori. Method o They wanted to investigate peptic ulcers, as Warren had previously conducted data on patients with gastrointestinal disease, and in every patient with ulcers, Pylori was found o They first tried to infect tissue cultures with the bacteria to no avail o Marshall then ingested it himself, and developed an ulcer which was more evidence for the bacteria causing ulcers o He then took antibiotics, and the ulcer began to resolve itself, furthering proof of their hypothesis. Methodology o They used primary sources as they investigated the ulcers themselves  Deviation from Scientific Method o They challenged a widely held scientific and medical belief o They only had one successful test at start o Marshall’s ingestion of the bacteria raised ethical and self-preservation concerns o They were also scorned by the scientific community at first before more experiments were conducted Conclusion o They concluded that peptic ulcers were caused by bacteria Background Information o The long-standing assumption was that ulcers were caused by stress, spicy foods and too much stomach acid o Peptic Ulcers are sores that develop on the stomach lining o It was built off Warren’s past observations of spiral bacterium in patients with gastric diseases Van Helmont: Hypothesis o Plants grew from external sources other than the soil that the plant was planted in Method o He dried out 200 pounds of soil to get rid of any water weight o He planted a willow sprout (5 pounds) in it and moistened it with distilled water o He observed after 5 years that the willow tree had grown to 169 pounds, whilst the soil had only decreased by two ounces. Methodology o He conducted primary investigations and was trying to “learn through experimentation”  Deviation from Scientific Method: o He did not control enough variables except the soil and quite poorly, the water, such as sunlight and temperature o He did also not include a control which in this experiment, would be appropriate o He also used quantitative data rather than qualitative data, which was most common during the Renaissance era. Conclusion o He concluded that the commonly held belief that plants grew from transforming soil into bark, roots and leaves was false. o However, he incorrectly misinterpreted the results that the plants growth stemmed from water purely rather than other external source Background Information o The growth of the plants really came from the cycle of photosynthesis, which converted CO2 into glucose and subsequently cellulose Spencer: Hypothesis o Microwaves could be harnessed to cook food efficiently Method o After noticing that a candy bar in his pocket had melted while testing out a magnetron (microwave emitting device), he conducted more experiments with food and microwaves o He heated up popcorn and eggs both having successful results, and both being informal tests Methodology o He conducted his own investigations, making him a primary source. Deviation from Scientific Method o He did not have a formal aim or hypothesis in mind when he carried out these experiments, as he did it out of curiosity  o He conducted many informal tests, as there were very little controlled variables. o His observation and subsequent application of these microwaves was serendipitous, meaning it was not observed under rigorous conditions intended for observation but rather by chance o He applied it to a product very quickly, with very little formal and valid scientific testing. Conclusion o He concluded that microwaves could be harnessed to heat food efficiently, if the microwaves were evenly exposed over the food. Background Information o Microwaves are a type of electromagnetic wave o The heat produced is called radiant heat which is the heat exchange of protons Practical Link o https://tinyurl.com/MicrowavesCaseStudyPractical Eratosthenes: Hypothesis o No specific hypothesis o Hypothesized that he could use the angles of the shadows cast to calculate the circumference of the Earth Method o He heard that no shadow was cast in Syene at zenith (June 21 st) o Placed a stick vertically in the ground at zenith in Alexandria (June 21 st) o Measured shadow in Alexandria to be 7.2°, while in Syene it was 0° o Hired a man to pace the distance between the two cities (in stadia) o Used simple proportions and math to calculate circumference of Earth ∠𝑎 𝑘𝑚 𝑏𝑒𝑡𝑤𝑒𝑒𝑛 𝑡𝑤𝑜 𝑎𝑟𝑒𝑎𝑠 o Equation used:360 = 𝑐𝑖𝑟𝑐𝑢𝑚𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑜𝑓 𝑒𝑎𝑟𝑡ℎ o ∠𝑎 is shadow angle o Was able to calculate the circumference of the Earth very precisely, especially without any accurate measuring instruments  Methodology o Fieldwork as well as primary investigation and sources as well as secondary sources o He also assumed that the sun's light fell in parallel beams onto Earth. Deviation from Scientific Method o Only conducted experiment once - unreliable o Didn’t verify secondary data – inaccurate Conclusion o He theorized that the Earth was approximately 40,000km in circumference o He was very close to the true value of 40,075km Practical o Measure the angle of one slice o Measure the outer edge o Apply to proportion equation. o The experiment wasn’t reliable nor accurate as we only conducted it once, and the Lebanese bread isn’t a perfect circle. Doppler: Hypothesis o Sound frequencies change, relative to the observer when emitted from a moving sound source Method o Christophe Ballot hired a group of 15 perfectly tuned trumpeters to remain stationary next to a railway and another 15 to play on a moving train towards them o He then had them commence playing at the same time  o He observed a change in pitch as the moving trumpeters went past but observed no change in the stationary ones. Methodology o Doppler conducted a primary experimental investigation who used quantitative data Background Information o Ballot lived next to a train line and noticed a change in pitch as the train approached and passed. Conclusion o Sound frequencies change, relative to the stationary observer as the emitter of sound moves Priestley: Hypothesis o Dephlogisticated air was released by green plants o A component of air is necessary for combustion and better respiration Method o A jar with a mouse and candle were placed under a sealed airtight jar. o The mouse died and the flame extinguished o The same experiment was repeated except a plant was placed under the jar too o The flame and mouse stayed alive  Methodology o Primary, Experimental, Qualitative Background Information o Priestley blasted mercuric oxide with sunlight and separated the oxygen and mercury before this experiment o Wanted to understand combustion and composition of air Collaboration o Was verified under stricter conditions by more recent scientists o Experiment was re-enacted multiple times Conclusion o He concluded that plants have “an opposite effect of breathing” which is now called photosynthesis o Debunking of phlogiston theory Practical: o Yeast mixed with hydrogen peroxide in a bag – white foam, warmth, bag expanded, bubbling/fizzing, dissolving – reaction is exothermic o Adding a glowing splint immediately relit it into fire – proved oxygen was produced Scientific Report Structure Abstract o Key findings o Summary Introduction o Hypothesis o Aim o Risk Assessment Method o Materials needed o Past tense passive Results o Data o Graphs o Tables Conclusion o Summary of results and trends  o Hypothesis supported/rejected Discussion o Trends o Errors o Limitations o External research o Secondary sources o Follow-up experiments Significant Figures Nonzero digits are sig. Interior zeros are sig. Zeros before non-zeros are not sig. Zeros after a non-zero with no decimal are not sig. Zeros after a non-zero with a decimal are sig. Working independently vs collaboratively Independently Collaboratively Advantages You don’t have to wait for There is a shared others to conduct their workload research Shared knowledge, also You are able to control meaning there are more all variables to how you specialized people deem fit. Saves time Can work flexibly New approaches to tasks could be implemented Disadvantages You are more likely to Conflict could arise have limited knowledge Other peers may not be as you cannot as skilled/competent as collaborate with others you Could be very time- People becoming consuming. unwilling to cooperate or understand others point of view Types of Methodology Quantitative Research Qualitative Research Correlational Research Mixed Methods Observational – Direct observation of the subject of an experiment with no interference by the scientist. Experimental – Deliberately manipulating a variable in a scientific experiment Descriptive – Describing what happens rather than why