Physics
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PhysicsLet’s learn about the quantum realm
On the smallest scales, the universe behaves in some pretty strange ways.
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PhysicsHow salty does the sea have to be for an egg to float?
Some objects float on top of the ocean, and other objects sink to the bottom. Why? Try this eggs-periment to find out!
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PhysicsScientists Say: Fusion
Nuclear fusion is the physics that powers the sun and could someday provide abundant clean energy on Earth.
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PhysicsScientists Say: Fission
Nuclear fission is the process of splitting atoms apart to release huge amounts of energy.
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AnimalsTiny bumps on polar bear paws help them get traction on snow
Super-small structures on the Arctic animals’ paws might offer extra friction that keeps them from slipping on snow, a new study concludes.
By Meghan Rosen -
PhysicsExplainer: What is friction?
The force of friction always acts to slow things down. It depends on just two factors: the surfaces and how hard they press together.
By Trisha Muro -
PhysicsExplainer: Radiation and radioactive decay
Like clockwork, radioactive forms of some elements shed parts of themselves as they attempt to become nonradioactive.
By Janet Raloff and Trisha Muro -
PhysicsExplainer: Radioactive dating helps solve mysteries
Knowing the decay rate of radioactive elements can help date ancient fossils and other artifacts.
By Trisha Muro -
EarthFossil-fuel use is confusing some carbon-dating measurements
Carbon-14 dating of recent artifacts will soon give scientists confusing results. That’s another price society pays for its reliance on fossil fuels.
By Trisha Muro -
PlantsWhy dandelions are so good at widely spreading their seeds
Individual seeds on a dandelion release most easily in response to winds from a specific direction. As the wind shifts, this scatters the seeds widely.
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TechA tool as small as a human cell can scan for contaminants and more
Tiny spectrometers might someday show up on smart devices. They could help people scan for ingredients or contaminants in foods and other materials.
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ChemistryScientists Say: Fluorescence
This property causes materials — including some animals’ skin, fur or feathers — to glow under light.