Tutorial
Science
Understanding how the world works through scientific principles.
Chapters
About this tutorial
Understanding how the world works through scientific principles.
Why Learn Science
- Make better decisions with evidence
- Understand health and medical information
- Evaluate claims and avoid misinformation
- Appreciate the natural world
- Think more clearly and critically
- Raise scientifically literate children
Contents
| Chapter | Topic |
|---|---|
| 01-scientific-method | How science works |
| 02-physics-basics | Forces, energy, motion |
| 03-chemistry-basics | Atoms, molecules, reactions |
| 04-biology-basics | Life, cells, evolution |
| 05-human-body | How your body works |
| 06-earth-science | Geology, weather, climate |
| 07-astronomy | Space, stars, and the universe |
| 08-ecology | Ecosystems and environment |
| 09-technology-science | Science behind everyday tech |
| 10-evaluating-science | Reading research and spotting BS |
The Scientific Method
How Science Works
- Observation - Notice something interesting
- Question - Ask why or how
- Hypothesis - Propose testable explanation
- Experiment - Test the hypothesis
- Analysis - Examine results
- Conclusion - Accept, reject, or modify hypothesis
- Replication - Others repeat to verify
Key Concepts
| Concept | Meaning |
|---|---|
| Theory | Well-tested explanation (not "just a guess") |
| Law | Description of what happens (not why) |
| Hypothesis | Testable prediction |
| Control group | Baseline for comparison |
| Variables | Things that change or are measured |
| Peer review | Experts check the work |
What Makes Good Science
| Good Science | Bad Science |
|---|---|
| Testable, falsifiable | Vague, untestable |
| Replicable | One-off results |
| Peer reviewed | Self-published |
| Acknowledges limits | Claims certainty |
| Updates with evidence | Ignores contrary data |
Physics Essentials
Forces and Motion
| Concept | Meaning | Example |
|---|---|---|
| Force | Push or pull | Gravity pulling you down |
| Mass | Amount of matter | Same on Earth and Moon |
| Weight | Force of gravity on mass | Less on Moon |
| Acceleration | Change in velocity | Car speeding up |
| Friction | Resistance to motion | Brakes stopping car |
Energy
| Type | Description | Example |
|---|---|---|
| Kinetic | Energy of motion | Moving car |
| Potential | Stored energy | Raised object |
| Chemical | Stored in bonds | Gasoline, food |
| Electrical | Moving electrons | Lightning |
| Thermal | Heat | Boiling water |
Conservation: Energy can't be created or destroyed, only converted.
Newton's Laws
- Inertia - Objects stay put or keep moving unless acted upon
- F=ma - Force equals mass times acceleration
- Action/Reaction - Every action has equal opposite reaction
Chemistry Essentials
Atoms and Molecules
| Term | Meaning |
|---|---|
| Atom | Smallest unit of an element |
| Element | Pure substance (one type of atom) |
| Molecule | Atoms bonded together |
| Compound | Molecule with different elements |
States of Matter
| State | Properties | Example |
|---|---|---|
| Solid | Fixed shape and volume | Ice |
| Liquid | Fixed volume, takes container shape | Water |
| Gas | Expands to fill container | Steam |
| Plasma | Ionized gas | Lightning |
Chemical Reactions
- Reactants → Products
- Bonds break and form
- Mass is conserved (same atoms, new arrangement)
- Energy may be released or absorbed
Biology Essentials
The Cell
All living things are made of cells:
| Component | Function |
|---|---|
| Nucleus | Contains DNA, controls cell |
| Mitochondria | Produces energy (ATP) |
| Cell membrane | Controls what enters/exits |
| Ribosomes | Makes proteins |
DNA and Genetics
| Term | Meaning |
|---|---|
| DNA | Molecule carrying genetic instructions |
| Gene | Segment of DNA coding for a trait |
| Chromosome | Package of DNA |
| Genome | All genetic material |
| Mutation | Change in DNA sequence |
Evolution
Core concepts:
- Variation exists in populations
- Some variations help survival/reproduction
- Those traits become more common (natural selection)
- Over time, species change
- All life shares common ancestors
Human Body Basics
Major Systems
| System | Function | Key Organs |
|---|---|---|
| Cardiovascular | Transport | Heart, blood vessels |
| Respiratory | Gas exchange | Lungs |
| Digestive | Process food | Stomach, intestines |
| Nervous | Control, sensing | Brain, nerves |
| Musculoskeletal | Movement, support | Muscles, bones |
| Immune | Defense | Lymph nodes, white cells |
| Endocrine | Hormones | Glands |
Health Implications
| Knowing This | Helps With |
|---|---|
| How digestion works | Diet choices |
| How immune system works | Understanding vaccines |
| How hormones work | Recognizing imbalances |
| How heart works | Cardiovascular health |
Earth Science
Plate Tectonics
| Feature | Cause |
|---|---|
| Earthquakes | Plates moving past each other |
| Volcanoes | Magma rising through crust |
| Mountains | Plates colliding |
| Rift valleys | Plates spreading apart |
Weather vs. Climate
| Weather | Climate |
|---|---|
| Short-term conditions | Long-term patterns |
| What's happening today | What's typical over decades |
| Unpredictable beyond ~10 days | Predictable trends |
Climate Change
Basic physics:
- Sun's energy enters atmosphere
- Earth radiates heat back
- Greenhouse gases trap some heat
- More greenhouse gases → more heat trapped
Astronomy Basics
Scale of the Universe
| Object | Distance from Earth |
|---|---|
| Moon | 1.3 light seconds |
| Sun | 8 light minutes |
| Nearest star | 4 light years |
| Milky Way diameter | 100,000 light years |
| Nearest galaxy | 2.5 million light years |
Key Concepts
| Concept | Meaning |
|---|---|
| Light year | Distance light travels in a year |
| Galaxy | Billions of stars bound by gravity |
| Black hole | Gravity so strong light can't escape |
| Big Bang | Universe expanded from hot, dense state |
Evaluating Scientific Claims
Red Flags
| Warning Sign | Why It's Suspicious |
|---|---|
| "Scientists don't want you to know" | Real science is published openly |
| "Miracle cure" | Medicine doesn't work like that |
| "Ancient wisdom" | Age doesn't equal truth |
| "Just asking questions" | Often hides agenda |
| Single study | Needs replication |
| No peer review | Not vetted by experts |
Better Sources
| Reliable | Less Reliable |
|---|---|
| Peer-reviewed journals | News headlines |
| Scientific consensus | Single study |
| Meta-analyses | Anecdotes |
| Expert organizations | Social media |
Reading Science News
Questions to ask:
- Who did the study? (Conflicts of interest?)
- How big was the sample? (Small = less reliable)
- Was it replicated?
- Correlation or causation?
- Does the headline match the actual findings?
Science in Daily Life
Applications
| Situation | Science Helps |
|---|---|
| Health decisions | Understanding evidence |
| Home repair | Basic physics and chemistry |
| Gardening | Biology, soil science |
| Cooking | Chemistry, food science |
| Weather prep | Meteorology |
| Energy use | Thermodynamics |
Teaching Kids
- Encourage questions
- Do simple experiments
- Visit science museums
- Watch nature documentaries
- Model curiosity
- Admit when you don't know
Resources
Books
| Book | Topic |
|---|---|
| A Short History of Nearly Everything | Science overview |
| Cosmos (Sagan) | Astronomy |
| The Selfish Gene | Evolution |
| Six Easy Pieces (Feynman) | Physics |
| What If? (Munroe) | Science with humor |
Other Resources
- Khan Academy (free courses)
- Crash Course (YouTube)
- Kurzgesagt (YouTube)
- SciShow (YouTube)
- Science journals (popular versions)
Key Takeaways
- Science is a method, not just facts - It's how we know things
- Uncertainty is honest - Real scientists say "probably" and "evidence suggests"
- Consensus matters - Expert agreement is meaningful
- Correlation ≠ causation - Related doesn't mean one caused the other
- Science updates - Changing with evidence is strength, not weakness
- Question claims - Especially those that sound too good to be true
- Basic science helps daily life - Understanding how things work is practical