What you will learn
- how and why scientific knowledge changes over time,
- how scientists from different fields and cultures work together,
- how society shapes scientific questions, and scientific findings shape policy,
- how to analyse a real socio-scientific issue (vaccines, climate, antibiotics, DNA),
- how communication of science influences public decisions and individual choices.
In 1869 Dmitri Mendeleev arranged the known elements into a table by atomic mass and chemical behaviour. He left gaps where no known element fitted, and predicted what those missing elements would be like. Within 15 years, gallium (1875) and germanium (1886) were discovered — and closely matched his predictions. Why is this story a good example of “science as a human endeavour”?
- Mendeleev used existing evidence (known elements’ properties) to build a new pattern.
- His table made testable predictions about elements nobody had seen.
- Later discoveries tested and confirmed the pattern.
- Other scientists then refined the table (Moseley re-ordered it by atomic number, not mass).
Key idea: scientific theories are strongest when they predict things nobody has yet observed — and are then confirmed.
1. Scientific knowledge changes
Why theories change. When new evidence, better instruments, or new ways of thinking come along, old theories are revised or replaced. Examples:
- Earth-centred to Sun-centred universe (Ptolemy Copernicus, Galileo, Kepler).
- Phlogiston to oxygen in combustion theory (Priestley, Lavoisier).
- Continental drift to plate tectonics (Wegener rejected; later seafloor-spreading evidence accepted in the 1960s).
- Ulcers from stress to ulcers from bacteria (Marshall and Warren, 1980s — earned a Nobel Prize).
Change does not mean “science was wrong before.” It means science is self-correcting: ideas that fail against new data are dropped, improved ones replace them.
2. Multidisciplinary science and many perspectives
Modern science rarely happens in one field alone.
- Climate science brings together physicists (radiation), chemists (CO cycle), biologists (ecosystems), geologists (ice cores), and mathematicians (modelling).
- Medical research combines biology, chemistry, statistics, ethics, and medicine.
- Space exploration needs engineers, astronomers, materials scientists, programmers and biologists.
Scientists also bring different perspectives:
- First Nations knowledge: Aboriginal and Torres Strait Islander people have detailed knowledge of ecosystems, seasonal cycles, and fire management built up over tens of thousands of years. Modern bushfire management now increasingly draws on cultural burning practices.
- International teams: CERN (particle physics), the International Space Station, and the COVID-19 vaccine effort all spanned many countries.
- Diverse backgrounds: more women and researchers from under-represented groups bring new questions and interpretations to old problems.
List four different areas of expertise that had to work together to produce a COVID-19 vaccine in about a year.
- Virology / molecular biology — identify and sequence the virus, find protein targets.
- Immunology — design something the immune system will respond to.
- Chemistry / biotechnology — produce mRNA or protein at scale; stabilise it.
- Clinical trials (medicine + statistics) — test safety and efficacy in volunteers.
- Manufacturing and logistics (engineering) — ship hundreds of millions of doses safely.
- Public health and ethics — decide who gets doses first.
Key idea: no single laboratory or discipline could have done this alone.
3. Socio-scientific issues: ethics, environment, economics
A socio-scientific issue is one where science informs a decision but the decision also involves ethical, environmental, social and economic trade-offs.
Examples: climate policy, genetically modified crops, fluoride in drinking water, nuclear power, vaccine mandates, antibiotic overuse, fast-fashion chemicals in rivers.
A useful framework when analysing any such issue:
- What does the science actually say? (Strong evidence, early findings, or contested?)
- Who benefits and who bears the cost? (Economic, health, cultural.)
- What are the environmental impacts? (Short- and long-term.)
- What ethical questions are at stake? (Fairness, autonomy, consent, future generations.)
- What trade-offs are acceptable? (And to whom?)
Overuse of antibiotics in hospitals and farming is driving the rise of “superbugs” resistant to treatment. Identify a science angle, an economic angle, and an ethical angle.
- Science: bacteria evolve resistance through natural selection; wider antibiotic use speeds this up.
- Economic: new antibiotics are expensive to develop; farms get cheaper meat with routine antibiotics in feed.
- Ethical: future patients may die from formerly treatable infections. Is it fair to trade cheaper meat today for greater disease risk tomorrow?
Key idea: the science identifies the problem, but choosing what to do requires weighing costs across groups and generations.
4. Communicating science
Science only changes what people do if it is communicated well. Communication influences:
- Individual choices: deciding to vaccinate, recycle, cut sugar, buy an EV.
- Community policy: water restrictions, fluoride in drinking water, local speed limits near schools.
- National regulation: chemical bans, emissions targets, vaccination requirements.
Good science communication:
- Uses plain language and clear visuals.
- States what is well supported and what is uncertain.
- Cites evidence and sources.
- Acknowledges trade-offs rather than over-promising.
Poor science communication:
- Exaggerates certainty (or uncertainty).
- Mixes up correlation and causation.
- Cherry-picks data to support a pre-chosen view.
- Attacks critics instead of addressing their evidence.
“Chocolate proven to prevent heart attacks — new study!” What questions should a careful reader ask?
- Who ran the study, and who paid for it? (Watch out for industry-funded research.)
- How big was the sample? A small study can find anything by chance.
- Was it a real experiment or just a correlation (people who ate chocolate also exercised more)?
- Has the result been repeated by other scientists?
- “Proven” is a huge word. Science rarely proves — it accumulates evidence.
Key idea: healthy skepticism is part of how science defends itself against hype.
5. Case study: climate change
A textbook example of socio-scientific decision-making.
- Evidence: temperature records, ice cores, atmospheric CO measurements (Mauna Loa since 1958), sea-level data, species range shifts, modelling.
- Multidisciplinary: physics, chemistry, biology, geology, statistics, computing.
- Knowledge has changed: early 1900s scientists (Arrhenius) proposed CO warming effects; modern measurements have made the relationship overwhelming.
- Ethical dimensions: wealthier countries emitted most historical CO; poorer countries face some of the worst impacts first.
- Policy response: national emission targets, renewable subsidies, carbon pricing, international treaties (Paris Agreement, 2015).
- Communication challenges: tipping points and probabilities are hard to translate into everyday language.
Practice: Year 8
How science works
- Explain in your own words why scientific knowledge is not “fixed”.
- Give one example where a scientific theory was revised because of new evidence.
- What is meant by “multidisciplinary” research?
- Name three fields of science that would cooperate to study climate change.
- Give one example of scientific knowledge that has been refined by First Nations knowledge in Australia.
Socio-scientific issues
- Define a socio-scientific issue and give one example.
- List four types of consideration (ethical, environmental, social, economic) using a single example.
- Why might different groups reach different conclusions about a scientific policy?
- Give one example where science changed a government’s rules about safety or health.
Analyse and argue
- A TV ad says “nine out of ten dentists recommend this toothpaste.” Suggest three questions a scientist would ask before trusting this claim.
- Describe one advantage and one risk of social media as a way to communicate science.
- Explain why “the science is never settled” is sometimes used honestly and sometimes used to delay action.
- A community debates whether to fluoridate the water supply. Outline one scientific argument in favour and one ethical argument against.
Case studies
- Vaccines. Using what you know about multidisciplinary work, list four types of expert involved in bringing a new vaccine from research to public rollout.
- Climate policy. Give one economic benefit and one environmental cost of a coal-fired power station. Then suggest a third factor (social or ethical) that policy-makers should weigh.
- Antibiotics. Suggest two actions — one at the individual level, one at the policy level — that could slow the rise of antibiotic-resistant bacteria.
- Mendeleev’s periodic table. Explain why the later discovery of the noble gases (argon, helium, etc.) did not destroy Mendeleev’s table and instead strengthened it.
Challenge
Harder reasoning
- The 1980s Marshall-Warren discovery that most stomach ulcers are caused by the bacterium H. pylori overturned the then-accepted idea that ulcers were caused by stress and diet. Use this case to argue that science benefits from listening to researchers who challenge the majority view — while still demanding evidence.
- Compare how scientific evidence on tobacco (developed from 1950s onwards) and climate change (developed from 1960s onwards) were communicated to the public. What patterns do you see in how industries respond to unwelcome findings?
- A science reporter claims that “polls say of people doubt evolution, so scientists should be less certain.” Evaluate this reasoning using the idea that science is decided by evidence, not popularity.
- Choose any current socio-scientific issue (climate, AI, genetic engineering, nuclear, vaccines). Describe the key science, list two stakeholders with conflicting interests, and argue for a position — then state what evidence would make you change your mind.