GK
BIG BANG THEORY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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By looking through a telescope and seeing everything moving away
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By looking at a star’s spectrum and seeing the red shift
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By looking at a star’s spectrum and seeing the blue shift
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The universe is not expanding
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Detailed explanation-1: -When looking at the radiation emitted by distant stars or galaxies, scientists see emission spectra ‘shifted’ towards the red end of the electromagnetic spectrum-the observed wavelengths are longer than expected. Something causes the wavelength of the radiation to ‘stretch’.
Detailed explanation-2: -Answer: Astronomers observe a regular progression of galaxies which are expanding at progressively higher velocities as they measure galaxies at increasing distances. What they measure then is an expansion of the universe at both relatively recent times in addition to the early phases of the universe’s evolution.
Detailed explanation-3: -When an object is moving away from us, the light from the object is known as redshift, and when an object is moving towards us, the light from the object is known as blueshift. Astronomers use redshift and blueshift to deduce how far an object is away from Earth, the concept is key to charting the universe’s expansion.