Scientists Say

A weekly word defined, in a sentence and in context.

  1. Life

    Scientists Say: Genus

    A genus is a group of closely related species. It’s the first part of the two-part system called binomial nomenclature, used to name living things.

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  2. Chemistry

    Scientists Say: Alkaline

    Alkaline chemicals are basic — substances that produce hydroxide ions in solution.

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  3. Math

    Scientists Say: Pi

    Pi is the ratio of a circle’s circumference to its diameter. But some mathematicians say life would be easier if we used a different ratio instead.

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  4. Fossils

    Scientists Say: Dinosaur

    Dinosaurs emerged between 243 and 233 million years ago. While some died out 66 million years ago, others are still with us — birds.

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  5. Health & Medicine

    Scientists Say: Placebo

    In clinical trials, scientists often test a drug or procedure against a placebo — a treatment that has no effect — to find out how well their new treatment works.

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  6. Physics

    Scientists Say: Acceleration

    Acceleration is a change in velocity. That could mean a change in speed or in direction.

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  7. Physics

    Scientists Say: Radiation

    Radiation is the motion of energy through space as waves or particles.

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  8. Brain

    Scientists Say: Neuron

    Neurons are the foundational cells in the nervous system. They pass along and process information using electrical signals.

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  9. Life

    Scientists Say: Hominid

    Scientists are still working out what counts as a hominid. Some say it’s just people and our extinct ancestors. Others say add more apes.

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  10. Life

    Scientists Say: Egg and sperm

    An egg or a sperm cell contains half of the normal genes an organism needs. They fuse together to form a new individual.

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  11. Climate

    Scientists Say: Weather

    The state of the atmosphere in a specific place and time is weather. Over a long time, the weather conditions in an area will reveal its climate.

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  12. Space

    Scientists Say: Planet

    Planets have to orbit a star, be big enough to form a sphere and keep other objects out of their path around their star.

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