Scientists Say

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

  1. Brain

    Scientists Say: MRI

    MRI is a technique used to diagnose diseases and to study the body. The machine can map internal structures, all the way down to tiny blood vessels.

  2. Chemistry

    Scientists Say: Ion

    Some atoms and molecules have a positive or negative electrical charge. These are called ions.

  3. Environment

    Scientists Say: Fracking

    Liquid fuel sources such as natural gas and petroleum form deep underground between layers of rock. To retrieve them, engineers often use a technique called hydraulic fracturing, or fracking.

  4. Space

    Scientists Say: Gravitational lens

    A gravitational lens is an effect that occurs when a massive object lies between a viewer and something further away. The massive object’s gravity bends light arriving from the more distant object.

  5. Health & Medicine

    Scientists Say: Hormone

    This is a chemical that travels in the blood and acts as a signal. It can tell distant body parts what to do. When a chemical acts in this way, it has a special name.

  6. Environment

    Scientists Say: Microplastic

    Bits of plastic smaller than five millimeters are called microplastics. They can end up in the ocean, where corals might mistake them for food.

  7. Animals

    Scientists Say: Nematode

    Nematodes are a group of related small worms found all over the world. They can cause disease, but they also can be useful for scientists to study.

  8. Animals

    Scientists Say: Irruption

    Sometimes populations of animals can suddenly increase. The word for that is irruption.

  9. Chemistry

    Scientists Say: Fulgurite

    When lightning strikes in the right place, it can fuse minerals together in a glassy structure.

  10. Brain

    Scientists Say: Cortical homunculus

    If you draw a representation of your body as seen by your brain, it’s called a homunculus. On it, parts sensitive to touch or used for fine movement are large, while others are small.

  11. Health & Medicine

    Scientists Say: Circadian

    We often feel the pull of sleep when the sun goes down. Light and our own biology put us into a regular, 24-hour rhythm that has its own word.

  12. Brain

    Scientists Say: Blood-brain barrier

    Blood can contain nasty bacteria and other things you want to keep away from your delicate brain. The blood-brain barrier is up to the job.