Questions: Complete these sentences by matching the phrases below. Scientists smash together tiny bits of matter using: Scientists extrapolate backwards in time to derive: When light waves are emitted by a moving source, scientists can measure: The extremely low temperature of outer space can be explained as:

Solution Steps

The task is to complete sentences by matching them with appropriate scientific concepts or phenomena. Each sentence relates to a different area of physics or cosmology.

1. Scientists smash together tiny bits of matter using: This refers to particle accelerators, which are used to collide particles at high speeds to study fundamental forces and particles.

2. Scientists extrapolate backwards in time to derive: This is related to the Big Bang theory, where scientists use current observations to infer the conditions of the early universe.

3. When light waves are emitted by a moving source, scientists can measure: This describes the Doppler effect, which is the change in frequency or wavelength of light from a moving source.

4. The extremely low temperature of outer space can be explained as: This is related to the cosmic microwave background radiation, which is the thermal radiation left over from the Big Bang.

• Particle accelerators are used to smash together tiny bits of matter.
• The Big Bang theory is derived by extrapolating backwards in time.
• The Doppler effect is measured when light waves are emitted by a moving source.
• Cosmic microwave background radiation explains the extremely low temperature of outer space.

Final Answer