Scientists Say

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

  1. Space

    Scientists Say: Quasar

    This word describes the bright-shining core of a galaxy in which a supermassive black hole sucks in matter and releases a huge amount of energy.

    By
  2. Microbes

    Scientists Say: Amoeba

    Amoebas are single-celled microbes that move and eat with shape-shifting bulges that extend from their cells. Some are blobs. Others build a shell.

    By
  3. Earth

    Scientists Say: Jurassic

    During this time from about 200 million to 145 million years ago, dinosaurs reigned and many animals evolved, including birds and some early mammals.

    By
  4. Animals

    Scientists Say: Echolocation

    This word describes a method that some animals use to sense their environments by making sounds and listening for their echoes.

    By
  5. Earth

    Scientists Say: Ring of Fire

    This horseshoe-shaped path on the fringes of the Pacific Ocean holds most of the world’s active volcanos and earthquake sites.

    By
  6. Physics

    Scientists Say: Photon

    This word describes light as a particle. A photon is the tiniest possible bit of electromagnetic radiation.

    By
  7. Life

    Scientists Say: Enzyme

    This word describes a molecule that speeds up chemical reactions in living things. Enzymes work by lowering the energy needed for a reaction to occur.

    By
  8. Brain

    Scientists Say: Brainwaves

    These patterns of electrical activity in the brain look like spikes or waves.

    By
  9. Earth

    Scientists Say: Meteorology

    This word describes the study of processes in the Earth’s atmosphere, including the weather.

    By
  10. Space

    Scientists Say: Light-year

    This is the distance light travels in one year — about 9.48 trillion kilometers. Light-years are used to measure vast distances, like those in space.

    By
  11. Life

    Scientists Say: Fermentation

    Fermentation breaks down carbohydrates, such as sugars, producing energy and making gases, acids or alcohol. This process can help make foods and fuels.

    By
  12. Fossils

    Scientists Say: Fossil

    Under the right conditions, living things or traces they’ve left behind can be preserved in rock for a long time — millions or billions of years.

    By