In 1929, the astronomer Edwin Hubble observed that the light from galaxies moving away from the Earth had longer wavelengths than expected - AQA - GCSE Physics - Question 2 - 2018 - Paper 1
Question 2
In 1929, the astronomer Edwin Hubble observed that the light from galaxies moving away from the Earth had longer wavelengths than expected.
What name is given to th... show full transcript
Worked Solution & Example Answer:In 1929, the astronomer Edwin Hubble observed that the light from galaxies moving away from the Earth had longer wavelengths than expected - AQA - GCSE Physics - Question 2 - 2018 - Paper 1
Step 1
What name is given to this effect?
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Answer
The effect observed by Edwin Hubble is called red-shift.
Step 2
What relationship between the speed of a galaxy and the distance is suggested by Hubble's results?
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Answer
Hubble's results suggest that the further away from the Earth, the faster a galaxy is moving. This indicates a linear relationship between distance and speed.
Step 3
Give one strength and one weakness of this model in representing the idea of an expanding Universe.
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Answer
Strength: As the balloon expands, the dots (representing galaxies) get further apart, which visually illustrates the galaxies moving away from each other. Weakness: The dots are only on the surface of the balloon; this model does not accurately represent the distribution of galaxies throughout the universe as there are limitations in how far the balloon can expand.
Step 4
In what way do the observations made by Hubble support both Theory 1 and Theory 2?
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Both theories suggest that the Universe is expanding.
Step 5
Suggest what is likely to have caused scientists to start thinking Theory 1 is wrong.
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Scientists are likely to have considered new evidence or observations that cannot be explained by Theory 1, such as findings related to the Cosmic Microwave Background Radiation (CMBR).
