Scientists Say

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

  1. Life

    Scientists Say: Protein

    Proteins are molecules made up of building blocks called amino acids. They play many key roles in the body’s cells and are essential for life.

    By
  2. Physics

    Scientists Say: Momentum

    This word describes a property of a moving object based on its mass and the direction and speed of its motion.

    By
  3. 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
  4. 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
  5. 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
  6. 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
  7. 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
  8. Physics

    Scientists Say: Photon

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

    By
  9. 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
  10. Brain

    Scientists Say: Brainwaves

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

    By