UPSC Prelims 2012 · Question 19 of 98

UPSC Prelims 2012 question on Expanding Universe Evidence

Which of the following is/are cited by the scientists as evidence/evidences for the continued expansion of universe?

1. Detection of microwaves in space.

2. Observation of redshift phenomenon in space.

3. Movement of asteroids in space.

4. Occurrence of supernova explosion in space.

Select the correct answer using the codes given below.

  1. 1 and 2
  2. 2 only
  3. 1, 3 and 4
  4. None of the above can be cited as evidence
Show answer

Answer: A. 1 and 2

Verdict

Correct Answer: 1 and 2 only

Statements 1 and 2 are correct because cosmic microwave background radiation and redshift are key evidences for the expanding universe, while asteroid motion and ordinary supernova explosions are not direct evidence.

Analysis

The continued expansion of the universe is supported by major cosmological observations such as cosmic microwave background radiation and redshift of distant galaxies.

Statement by statement

1. Detection of microwaves in space — Correct

This refers to Cosmic Microwave Background Radiation.

It is considered the afterglow of the Big Bang and supports the idea that the universe has expanded and cooled over time.

2. Observation of redshift phenomenon in space — Correct

Redshift shows that light from distant galaxies is stretched to longer wavelengths.

This indicates that galaxies are moving away from us and that the universe is expanding.

3. Movement of asteroids in space — Incorrect

Asteroid movement is mainly governed by gravity within the solar system.

It is not evidence for the expansion of the universe.

4. Occurrence of supernova explosion in space — Incorrect

A supernova is a stellar explosion and by itself is not direct evidence of universal expansion.

However, certain Type Ia supernovae are used as standard candles to measure cosmic distances and study the rate of expansion.

Extra UPSC info

* Cosmic Microwave Background Radiation was discovered in 1964.

* Redshift of galaxies was observed by Edwin Hubble and supports the expanding universe model.

* Greater redshift generally indicates that a galaxy is moving away faster.

* Type Ia supernovae helped establish the idea of accelerating expansion of the universe.

* Accelerating expansion is linked to the concept of dark energy.

* Do not confuse local motion within the solar system with expansion of the universe.

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