Scientists Say

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

  1. Chemistry

    Scientists Say: pH

    pH is a scale used to measure the acidity or alkalinity of a solution. The scale ranges from zero to 14, with seven as the perfect neutral middle.

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  2. Scientists Say: Mineral

    Minerals are chemical elements or compounds that form repeating crystal structures. Quartz is a mineral. Table salt is, too.

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  3. Health & Medicine

    Scientists Say: Olfactory

    Smell something? Thank your olfactory sense. Olfactory refers to anything having to do with smell.

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  4. Animals

    Scientists Say: Hertz

    Frequency is how often something repeats over a period of time. Frequency is often measured in hertz, the number of times a cycle repeats each second.

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  5. Physics

    Scientists Say: Big Bang

    The Big Bang is the current theory about how our universe came to be. It began with a vast explosion of matter — a very Big Bang.

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  6. Life

    Scientists Say: Mitosis

    Mitosis is a type of cell division where one cell divides into two identical copies, called daughter cells.

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  7. Animals

    Scientists Say: Hagfish

    Hagfish are eel-shaped fish with many traits that make them similar to long-vanished fossils. When threatened, they can pump out piles of slime.

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  8. Health & Medicine

    Scientists Say: Obesogens

    The chemicals can change how the body stores fat or how often someone feels hungry — increasing the risk for obesity.

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  9. Climate

    Scientists Say: Eyewall

    The calm center of a hurricane or other tropical cyclone is called the eye. But the worst winds and rain are around it, in the eyewall.

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  10. Chemistry

    Scientists Say: Ferrofluid

    Ferrofluids are liquids with tiny magnetic particles in them. These liquids respond to magnets.

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  11. Scientists Say: Naloxone

    This drug can save people who have overdosed on opioids, such as fentanyl and oxycodone.

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  12. Physics

    Scientists Say: Light pollution

    Light pollution is when artificial light shines into places that are normally dark. It can disrupt the lives of plants, animals and people.

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