Oxygen in a galaxy that is moving away from us emits light with a wavelength of 501 nm.Identify the wavelength of the light when detected on Earth. Greater than 501 nm due to redshiftLess than 501 nm due to redshiftExactly 501 nm – there is no redshift under these conditions

A star at a temperature of 8200 K is observed in a distant galaxy at redshift = 2.7.(i) Which equation relates the observed wavelength, to the actual wavelength, , emitted by the star? Select the correct option from the following.

A distance galaxy is moving away from us at a speed of 47380367 m/s. For hydrogen gas in this galaxy, calculate the wavelength (in nm) to one decimal place of the hydrogen alpha line as observed here on earth. Note: This wavelength emitted by hydrogen is measured in the first year physics lab to be 656.2 nm.

A specific spectral line from a distant galaxy has been red shifted from a wavelength of 450 nm to 762 nm. At what speed (as a fraction of c) is the galaxy receding from the Earth? No units are needed.

When the light from a distant galaxy is analysed, it is found that a line on its spectrum is 32 nm longer than when the same spectrum is produced on Earth. Given that the light was emitted with a wavelength of 430 nm, calculate the cosmic scale factor when it was emitted. Give your answer to 2 significant figures.

1Which of the following statements is incorrect?Red-shift is the observed decrease in the frequency of the light which we receive from distant galaxiesRed-shift is the observed increase in the wavelength of the light which we receive from distant galaxiesRed-shift leads to a decrease in the amount of red light and an increase in the amount of light of other wavelengths which we receive from distant galaxiesRed-shift occurs when a light source is moving away from the observer2When we look at the spectrum of the Sun or any star, we find that light of certain wavelengths (colours) appears to be missing.  These missing wavelengths appear as a series of black lines on a spectrum.  What causes this light to be ‘missing’ from a spectrum?Light of these wavelengths is absorbed by the atmosphere of the starLight of these wavelengths is not produced by the starLight of these wavelengths is incapable of travelling the huge distance from the star to the EarthLight of these wavelengths is absorbed by the atmosphere of the Earth3Which of the following statements is NOT supported by the observation of red-shift in the light we receive from other galaxies?The Universe is expandingThe Universe (may have) started with the Big BangOur galaxy is at the centre of the Universe(Most) galaxies which are further from us are moving away from us more quickly4According to theory, how long has passed since the Big Bang occurred (in other words, how old is the Universe)?15.2 billion years4.5 billion years10.3 billion years13.8 billion years5Which of the following is NOT stated by the Steady State theory?The density of the Universe remains constantNew galaxies are not created within the UniverseThe Universe didn’t start with a big bangThe Universe has no beginning, middle or end6Which of the following statements about Cosmic Microwave Background (CMB) radiation is incorrect?It tells us that the Universe is cooling as it expandsIt is a form of electromagnetic radiationAs the Universe expands, the wavelength of this radiation decreasesIt can be thought of as leftover radiation from the Big Bang