Red shift blue shift

Front

What is redshift?

Back

Redshift is the phenomenon where light from an object moving away from an observer is shifted towards the red end of the electromagnetic spectrum, indicating that the object is receding.

Front

What is blueshift?

Back

Blueshift is the phenomenon where light from an object moving towards an observer is shifted towards the blue end of the electromagnetic spectrum, indicating that the object is approaching.

Front

What does the Doppler effect describe?

Back

The Doppler effect describes the change in frequency or wavelength of a wave in relation to an observer moving relative to the wave source.

Front

How do astronomers use redshift to determine the movement of galaxies?

Back

Astronomers observe the absorption spectra of galaxies; if the lines are shifted towards the red end, it indicates that the galaxy is moving away from us.

Front

What is the significance of the Hubble telescope in astronomy?

Back

The Hubble telescope allows astronomers to observe distant galaxies and celestial objects, providing insights into the universe's history and structure.

Front

What is the estimated age of the universe?

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Scientists estimate the universe is approximately 13.8 billion years old.

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What is the relationship between redshift and the expansion of the universe?

Back

Redshift is evidence of the expansion of the universe; as galaxies move away, their light shifts to red, indicating that the universe is expanding.

Front

What is the electromagnetic spectrum?

Back

The electromagnetic spectrum is the range of all types of electromagnetic radiation, including visible light, radio waves, and X-rays.

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What is the significance of the cosmic microwave background radiation?

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The cosmic microwave background radiation is the afterglow of the Big Bang, providing evidence for the universe's early state and expansion.

Front

What is a galaxy?

Back

A galaxy is a massive system of stars, stellar remnants, interstellar gas, dust, and dark matter, bound together by gravity.