The Scientific Method and Peptic Ulcers

Peptic ulcers are caused by the bacterium Helicobacter Pylori.

A systematic approach to investigation, including observation, hypothesis formation, experimentation, and analysis.

Marshall intentionally ingested Helicobacter Pylori to induce an ulcer, proving the bacterial nature of the illness.

Investigated the source of plant growth using a willow tree, contrasting soil weight with plant weight.

A species of bacteria that can cause peptic ulcers.

Used to test causal relationship of Helicobacter Pylori with peptic ulcers.

Van Helmont's hypothesis proposed that plants do not primarily grow from the soil, but from another source.

Peptic Ulcers are sores that develop on the stomach lining, causing discomfort or pain.

Microwaves could efficiently cook food.

Lack of formal aim, hypothesis, and controlled variables made the experiment informal.

Direct observation or experimentation, as opposed to secondary research.

Factors other than microwaves that could have affected food heating.

A group in an experiment that is not exposed to the treatment being tested, used for comparison.

An accidental discovery made during an experiment, not the intended result.

Data based on descriptions or observations; not numerical measurements.

Plants do not grow solely from transforming soil.

A method to calculate the Earth's circumference using the angle of shadows cast by the sun at different locations on Earth.

Using the angle of shadows cast by the sun to calculate the Earth's circumference.

A fundamental assumption in Eratosthenes' calculation, assuming sunlight reaches Earth in parallel beams.

Measurement of the angle of the shadow cast by a vertical stick at a specific time and location.

Determination of the Earth's perimeter using observed angles and distances between locations.

The experiment's single data point makes it unreliable and the lack of precise measuring tools affects accuracy.

Heat transferred in the form of electromagnetic waves; in this case, microwaves.

The calculated value of the Earth's perimeter (40,000km) that Eratosthenes found to be remarkably close to the true value of 40,075km.

The frequency of sound waves changes depending on the relative motion of the sound source and the observer. This means the pitch of the sound will appear higher when the source is moving towards the observer and lower when it's moving away.

Doppler used two groups of trumpeters, one stationary and one on a moving train. He observed a change in pitch as the train passed, suggesting the frequency of sound changed due to movement.

Priestley believed that plants released a vital component of air that was necessary for combustion and respiration. He called this component 'dephlogisticated air'.

Priestley placed a mouse and a candle in a sealed jar. They died quickly. Then he placed a plant in the jar with a mouse and candle. The mouse and candle remained alive, leading him to conclude that plants release a life-sustaining component of air.

Phlogiston was a hypothetical substance believed to be released during combustion and respiration, causing objects to burn.

Priestley concluded that plants release a substance that is the opposite of breathing, which we now know as photosynthesis. He also debunked the phlogiston theory.

A typical scientific report follows a standardized structure including an abstract, introduction, method, results, conclusion, and discussion. Each section serves a specific purpose to clearly present the research findings and analysis.

Significant figures are the meaningful digits in a measurement. They indicate the precision of the measurement and are important when performing calculations.

Zeros that are considered part of a number's precision and contribute to its value.

Zeros that come before the first non-zero digit in a number and are not considered significant.

Zeros that come after the last non-zero digit in a number. Their significance depends on the presence of a decimal point.

A way of working where individuals contribute to a common goal, sharing knowledge, responsibilities, and tasks.

A research approach that uses numerical data and statistical analysis to test hypotheses and draw conclusions.

A research approach that explores subjective experiences, perspectives, and meanings using non-numerical data such as interviews and observations.

A research method where the researcher manipulates one or more variables to observe their effects on another variable.

A research approach where the researcher observes and records natural phenomena without interfering.