Latest posts
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What Is Half-Life?
A half-life is the time it takes for half of a quantity to decay or be removed. It describes radioactive atoms, drug levels in the blood, and anything else that decays at a rate proportional to how much is left.
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What Is Osmosis?
Osmosis is the movement of water across a semi-permeable membrane toward the side with more dissolved solute. It is why plant cells firm up and why salted vegetables wilt.
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Why Do Stars Twinkle?
Stars twinkle because Earth’s turbulent atmosphere bends their light as it travels. Planets usually shine steadily because they are close enough to appear as tiny discs rather than points.
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What Is the Gut Microbiome?
The gut microbiome is the community of trillions of microbes living in our digestive tract. They help digest fibre, train the immune system and produce compounds that affect the whole body.
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What Is the Doppler Effect?
The Doppler effect is the change in a wave’s frequency when the source and the observer move relative to each other. It explains the siren pitch drop and how we measure cosmic expansion.
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Why Is the Ocean Blue?
The ocean is blue mainly because water absorbs red light more strongly than blue. Sky reflection contributes, but it is not the main reason.
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How Do Tornadoes Form?
A tornado needs warm humid air, cool dry air above it and wind that changes direction with height. When those line up inside a thunderstorm, rotation can reach the ground.
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What Is Dark Matter?
Galaxies rotate far too fast for the matter we can see. Dark matter is the name for whatever extra mass is holding them together, and we still do not know what it is.
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What Is a Tsunami?
A tsunami is not a tall wave at sea — it is a very long wave that only becomes tall when it reaches shallow water. That is why it arrives so differently from a storm wave.