Comprehensive Scientific Method, Models, Theories, and Laws Review

Flashcards covering scientific investigations, historical discoveries, qualitative and quantitative data, modeling types and refinements, evolutionary theories, cosmological models, atomic models, scientific laws, and energy conservation.

What is an observation, and how is a scientific investigation defined?

An observation is any information acquired through the use of the senses (sight, sound, taste, smell, touch). A scientific investigation is a systematic approach to answer a question about the universe using the scientific method.

What are the six steps of the scientific method?

1. Make an observation or observations. 2. Ask questions about the observations and gather information. 3. Form a hypothesis and make predictions based on it. 4. Test the hypothesis and predictions in a reproducible experiment. 5. Analyze the data and draw conclusions (accept, reject, or modify hypothesis). 6. Reproduce the experiment until there are no discrepancies between observations and theory.

What key scientific discovery was made by Archimedes, and what did it enable?

Archimedes devised a method to test the purity of a golden crown while sitting in a bath, realizing it when water displaced and shouting "Eureka!". His observations enabled further investigations into forces, density, and composition.

What observation did Galileo Galilei make regarding Jupiter, and what cosmological model did it support?

Galileo observed four bright spots moving across the sky alongside a "star," remaining in line but changing positions each night. This proved Earth was not the only center of motion in the solar system, providing support for the heliocentric model.

How did Alexander Fleming discover penicillin?

Fleming left out sealed petri dishes with staphylococci cultures which became contaminated by mold (Penicillium notatum). He noticed no bacterial growth around the mold, leading to the isolation of penicillin and the development of the first antibiotic 10 years later.

How did Aboriginal and Torres Strait Islander Peoples utilize firestick farming as an ecosystem management technique?

Practiced for over $50,000$ years, firestick farming increased species like goannas, enhanced plant community diversity, reduced large Australian summer wildfires, added nutrients to the soil, triggered germination, and promoted fresh plant growth.

What is the primary difference between qualitative and quantitative data?

Qualitative data provides non-numerical information about qualities or characteristics (e.g., soil color, skin softness). Quantitative data provides numerical information based on measurements that are often tied to specific units (e.g., body temperature in $^\text{o}\text{C}$, time in seconds).

How do primary data and secondary data differ?

Primary data is collected first-hand or directly observed by the person using it (e.g., experimental measurements). Secondary data is collected second-hand by a person other than the one using it (e.g., textbooks, journal articles, web pages).

According to the provided diagram, how do analogue and digital signals differ in sampling and representation?

Analogue technologies represent continuous data without discrete sampling points (such as dials or spectra). Digital technologies process information into binary bits ($1$ or $0$), producing discrete data points and eliminating parallax errors.

What are common sources of error associated with analogue versus digital technologies?

Analogue errors commonly include parallax errors from line-of-sight misalignments and noise (random fluctuations). Digital errors arise from overly simplifying data by collecting only programmed information and requiring proper calibration.

How did advancements in telescope resolution change human understanding of the universe?

Improving telescope resolution revealed that the Solar System was busier than previously thought, confirmed that other galaxies exist outside the Milky Way and are moving away, and enabled observations outside the visible light spectrum.

How does empirical data differ from anecdotal data?

Empirical data is acquired through rigorous testing, experimentation, and observation under controlled conditions. Anecdotal data consists of information from personal accounts rather than scientific inquiry.

What are independent, dependent, and controlled variables in an experiment?

An independent variable isn't affected by other variables; a dependent variable is measured and changes in response to the independent variable; a controlled variable is kept constant throughout the experiment to ensure validity.

When should a scatter plot be used instead of a column graph?

A column graph is used to compare numerical values across discrete categories. A scatter plot is used to display the relationship and identify patterns between two numerical variables using a trendline.

According to the provided table, what key scientific activities occur before an investigation versus after an investigation?

Before an investigation: asking questions, constructing hypotheses, and developing methods. After an investigation: assessing reliability, making inferences and conclusions, offering support for ideas in the discussion, and increasing data.

What are the traditional Aboriginal practices of food leaching and utilizing wonky holes?

Leaching involved roasting nuts in stone ovens and placing sliced nuts in dilly bags inside creeks to remove toxins. Wonky holes are underwater freshwater outlets in saltwater that clear rubble, promote coral growth, and serve as rich fishing grounds.

Why does the Arctic Tern migrate from the North Pole to South America?

The Arctic Tern lives near the North Pole during the Northern Hemisphere summer months (June, July, August). When summer ends, it migrates to the tip of South America to hunt food, using sunlight to illuminate the ocean surface.

Why do elements in Group 1 (alkali metals) share similar chemical properties?

They share the same number of valence electrons (valency of $1$), which gives them low ionization energy, low melting points, and high chemical reactivity.

What is pareidolia, and why do optical illusions occur?

Pareidolia is the human ability to see recognized shapes or images in random visual patterns. Optical illusions occur when the brain attempts to interpret visual input, tricking us into perceiving things that may not exist.

What causes the formation of Auroras?

Solar winds (plasma produced by nuclear fusion in the sun) distort Earth's magnetic field lines. As the deflection shield bends, solar wind particles enter Earth's atmosphere at these bends and create auroras.

What can cause outliers in experimental data, and why are they significant?

Outliers can be caused by flaws in experimental design (e.g., lack of control variables, bias) or measurement errors. They are significant because they assess data reliability, identify errors, and suggest areas for further investigation.

How did Louis Pasteur disprove the theory of spontaneous generation?

Pasteur demonstrated that liquid nutrient broth was spoiled by airborne microorganisms and particles entering the container, rather than living organisms arising spontaneously from the air itself.

How did Antoine Lavoisier disprove the phlogiston theory of combustion?

Lavoisier showed through precise measurements that phosphorus and sulfur gained weight when burned in air, proving that combustion results from combining with oxygen rather than releasing phlogiston.

Who were the key scientists involved in determining the double helix structure of DNA?

James Watson and Francis Crick proposed the double helix model based on "Photograph 51," an X-ray diffraction image produced by Raymond Gosling under the guidance of Rosalind Franklin.

What is Feynmanium, and why did Richard Feynman state element 137 is the theoretical limit of the periodic table?

Feynmanium is element $137$. Feynman showed that an atom containing $137$ protons would require its surrounding electrons to orbit faster than the speed of light to remain stable, which is physically impossible.

What four key observations support the Big Bang theory and an expanding universe?

1. Red shift of light from distant galaxies. 2. Abundance of light elements (observed helium-to-hydrogen ratio). 3. Discovery of the cosmic microwave background radiation in $1964$. 4. Hubble's law showing that distant galaxies recede at higher velocities.

What is a scientific model, and what are its five main aims?

A scientific model is a simplified representation of a feature of the world designed to make it easier to understand, define, quantify, visualize, and simulate.

What are the five main types of scientific models?

Diagrams, physical replicas, mathematical representations, analogies, and computer simulations.

In the standard SIR epidemic model diagram, what do the three main compartments represent?

They represent Susceptible ($S$), Infectious ($I$), and Recovered ($R$) individuals in a population.

How is the basic SIR model adapted to account for carrier states in diseases like tuberculosis?

It is updated by adding a "Carrier" pathway for infected individuals who do not fully recover and continue to harbor and transmit the infection.

How does the SIR model incorporate maternally-derived immunity for diseases like measles?

An initial compartment for "Maternally-derived immunity" is added before the Susceptible state, representing newborns born with passive protection from maternal antibodies.

How did John Snow use a diagrammatic model to resolve the Soho cholera outbreak?

Snow mapped cholera incidence cases across Soho, identifying a public water pump as the source; removing the pump handle successfully ended the epidemic.

What did Michael Faraday discover using his physical replica model of electromagnetism?

Faraday proved that the magnetic field generated by an electric current in a wire was at $90^\text{o}$ to the current, and that current direction determined magnetic field orientation.

Why was the Ptolemaic geocentric model eventually superseded by the Copernican model?

The geocentric model required up to $80$ epicycles to account for retrograde planetary motion, making it unworkably complex; Copernicus simplified planetary mechanics by placing the sun at the center.

How did Johannes Kepler refine the Copernican heliocentric model?

Using Tycho Brahe's detailed astronomical data, Kepler demonstrated that planets move in elliptical orbits rather than perfect circles, establishing one of his Three Laws of Planetary Motion.

How did atomic models evolve from Dalton to the quantum model?

Dalton (indivisible solid spheres) $\rightarrow$ Thomson (plum pudding with electrons in positive matrix) $\rightarrow$ Rutherford (dense positive nucleus, empty space) $\rightarrow$ Bohr (electrons in quantized shell orbits) $\rightarrow$ Quantum model (electron locations described by probability distributions).

What was observed in Rutherford's gold foil experiment, and what did it prove?

Bombarding gold foil with positive alpha particles caused some particles to deflect at large angles, proving that atoms contain a dense, positively charged center called the nucleus.

According to the provided chart, what fundamental distinction separates scientific theories from laws?

Theories (how) seek to explain underlying mechanisms and cause-and-effect relationships, whereas Laws (what) describe repeated observations, often using mathematical expressions.

What three criteria must be evaluated when conducting a secondary source investigation?

1. Accuracy (is information a true representation of reality?). 2. Reliability (is information consistent across trusted sources?). 3. Validity (does information directly address the question without logical fallacies?).

Who established four criteria (postulates) in 1884 to prove a causative link between a microorganism and a disease?

Robert Koch.

How did Jean-Baptiste Lamarck's mechanism of evolution differ from Charles Darwin's?

Lamarck proposed the inheritance of acquired characteristics via body part use and disuse. Darwin proposed natural selection, where differential survival and reproduction occur due to variable inherited traits.

What formula expresses Newton's Second Law, and what are its constituent variables and units?

$F = ma$, where $F$ is net force in Newtons ($\text{N}$), $m$ is object mass in kilograms ($\text{kg}$), and $a$ is acceleration in meters per second squared ($\text{ms}^{-2}$).

Under what physical conditions does Newton's Second Law fail to apply accurately?

At extremely small scales (quantum domain), extremely high speeds (relativistic speeds near light speed), and within very strong gravitational fields.

What mathematical relationship defines Avogadro's Law, and what do its variables represent?

$\frac{V}{n} = k$, where $V$ is gas volume, $n$ is gas amount in moles, and $k$ is a constant ($\frac{RT}{P}$) held under constant temperature ($T$) and pressure ($P$).

What does the Law of Superposition state regarding undeformed rock layers?

In undeformed stratigraphic sequences, the oldest rock strata will always be situated at the bottom of the sequence.

According to Mendel's Law of Dominance and the provided Punnett square, what phenotypic ratio results from crossing two heterozygous (Bb) pea plants?

A $3\text{ to }1$ phenotypic ratio of dominant purple flowers ($BB$, $Bb$) to recessive white flowers ($bb$).

What are four non-Mendelian inheritance patterns that exceptionize Mendel's Law of Dominance?

Incomplete dominance, codominance, multiple alleles, and polygenic traits.

What equation expresses Ohm's Law, and what units are used for each variable?

$I = \frac{V}{R}$, where current ($I$) is in Amperes, voltage ($V$) is in Volts, and resistance ($R$) is in Ohms.

How did James Prescott Joule demonstrate the Law of Conservation of Energy using the Joule apparatus?

A descending weight turned a paddle in water, proving that gravitational potential energy lost by the weight equaled internal thermal energy gained by the water through friction.

How does the Law of Conservation of Energy distinguish elastic from inelastic collisions in physics?

In an elastic collision (e.g., atomic collisions), kinetic energy is fully conserved without loss to heat or sound. In an inelastic collision (e.g., billiard balls colliding), kinetic energy is converted into other energy forms via internal friction.

How is mass-energy equivalence ($E = mc^2$) applied to explain nuclear fission reactions?

In nuclear fission, the total mass of the product atomic nuclei is less than the mass of the initial nuclei; this mass difference ($\Delta m$) is released directly as heat and light energy according to $E = mc^2$.

How did Enrico Fermi resolve James Chadwick's beta decay energy discrepancy?

In $1934$, Fermi proposed that an unseen particle called a neutrino was emitted during beta decay, carrying away the remaining kinetic energy predicted by mass-energy equivalence ($E = mc^2$).