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⚛️ Science knowledge pathLearn science.
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Explore memorable ideas from space, biology, physics and the mind. Each short explanation includes a memory hook before a focused quiz tests what stayed with you.
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What you will explore
Ten ideas, then ten recall questions
1
The arrow of time
Entropy measures how many microscopic arrangements can produce the same visible state. Systems usually move toward states with more possible arrangements.
2
Your stardust body
Most carbon, oxygen and iron atoms in your body were forged inside stars and scattered by stellar explosions.
3
How leaves breathe
Leaves exchange gases through microscopic pores called stomata. Guard cells open and close each pore to balance carbon dioxide intake and water loss.
4
Three-hearted octopuses
Two hearts pump blood through the gills; a third circulates it through the body. Their copper-rich blood appears blue.
5
The heat of lightning
A lightning channel can reach about 30,000°C for an instant—roughly five times the temperature of the Sun’s visible surface.
6
Why the Moon drifts
Tidal interactions transfer energy to the Moon, making it drift away from Earth by about 3.8 centimetres per year.
7
Memory reconsolidation
When a memory is recalled it briefly becomes flexible before being stored again, a process called reconsolidation.
8
Why ice floats
Hydrogen bonds lock water molecules into an open crystal structure, making ice less dense than liquid water.
9
The predictive brain
The brain continuously predicts sensory input, then updates its model using prediction errors.
10
The long day on Venus
Venus rotates so slowly that one rotation takes longer than its trip around the Sun.
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A quiz immediately follows the lesson to strengthen recall.
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