Which part of the living system did you change?
Labs / Biology
Epidemic (SIR)
Every dot is a person wandering around and bumping into neighbours. Green folks are susceptible, red are infected, and blue have recovered with immunity. Click inside the box to start an outbreak, then change the rules and watch the curve on the right rise and fall.
Labs / Biology / Epidemic (SIR)
Epidemic (SIR)
Every dot is a person wandering around and bumping into neighbours. Green folks are susceptible, red are infected, and blue have recovered with immunity. Click inside the box to start an outbreak, then change the rules and watch the curve on the right rise and fall.
Why it matters
Why explore this?
Living systems are connected and constantly changing. This model makes one biological process visible so you can test how its parts affect one another.
Explore
Try the model
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Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- What happens to the peak of the red band when you switch from Normal to Lockdown mobility?
- How high does the vaccinated fraction need to go before the outbreak fizzles out on its own?
- Does a longer contagious period make more people sick overall, or just draw the epidemic out?
- Can two outbreaks happen at once if you infect people in two far corners of the box?
- After the epidemic burns out, why do some green dots survive even with no one vaccinated?
Explain
Make sense of what happened
Explain the process as a chain: a change happens, the system responds, and that response affects what happens next. Use an observation from the model as evidence.
Check
Before you leave
How did the system respond?
How would you explain that response?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.