Explore the Mpemba effect mystery
About this idea
Investigate one of physics' strangest puzzles: under certain conditions, hot water freezes faster than cold water. This phenomenon has baffled scientists since Aristotle and still lacks complete explanation, making it perfect for curious minds.
On this page
How to get started
STEP 1
the phenomenon (3 minutes)
- Sometimes hot water freezes faster than cold water
- Seems to violate basic thermodynamics
- Named after Erasto Mpemba, Tanzanian student who noticed it in 1963
- But Aristotle, Francis Bacon, and Descartes all mentioned it!
- Still not fully explained by science
- Doesn't always happen - depends on specific conditions
STEP 2
possible explanations (5 minutes)
- Several competing theories:
- Evaporation: Hot water loses mass through steam, less water to freeze
- Convection: Hot water circulates more, distributing cold faster
- Dissolved gases: Cold water holds more dissolved gases, which may slow freezing
- Supercooling: Cold water can supercool below 0°C without freezing
- Hydrogen bonds: Hot water's different bond structure might freeze faster
- Container effects: Warm container melts frost, improves thermal contact
- No single explanation covers all cases
- Likely combination of factors depending on conditions
STEP 3
try IT yourself (4 minutes)
- Need: Two identical containers, freezer, thermometer
- Fill one with hot water (90°C), one with cold (20°C)
- Place both in freezer, check every 15 minutes
- Note when each freezes solid
- Critical factors:
- - Identical containers and volumes
- - Same freezer position
- - Uncovered (evaporation matters)
- - Record all conditions
- Results vary - sometimes works, sometimes doesn't!
STEP 4
why IT matters (3 minutes)
- Shows science doesn't have all answers
- Seemingly simple questions can be profound
- Reveals complexity in everyday phenomena
- Good reminder to question assumptions
- Active area of research - you could contribute!
- Teaches careful experimental design
What you’ll need
- optional: two identical containers, water, freezer, thermometer
Recommended resources
Tutorials & Learning
Progress milestones
Track your progress with these key achievements:
1
5 minutes
Understand the phenomenon
2
10 minutes
Learn possible explanations
3
15 minutes
Ready to experiment
Common challenges
Every beginner faces obstacles. Here's how to overcome them:
Experiment didn't work
Solution: That's normal! Effect is sensitive to conditions. Try varying water temperatures, container size, freezer settings. Document what doesn't work - that's science too!
Share your progress
Celebrate your achievements and inspire others:
- • Share this counterintuitive phenomenon
- • Conduct and document your own experiment
- • Discuss unsolved scientific mysteries