The Big Bang and Steady State are two theories of the origin of the Universe - Edexcel - GCSE Physics - Question 6 - 2022 - Paper 1

We start with the red shift formula:

[ z = \frac{(\lambda_g - \lambda_0)}{\lambda_0} ]

Substituting the values:

[ z = \frac{(6.72 \times 10^{-7} - 5.66 \times 10^{-7})}{5.66 \times 10^{-7}} ]

Calculating the numerator:

[ 6.72 \times 10^{-7} - 5.66 \times 10^{-7} = 1.06 \times 10^{-7} ]

Now substituting back:

[ z = \frac{1.06 \times 10^{-7}}{5.66 \times 10^{-7}} \approx 0.187 ]

Hence,

[ z \approx 0.024 ] (approximately 0.025).

Using the equation for recession velocity:

[ v = z \times c ]

Where ( z ) is approximately 0.025 and ( c = 3.00 \times 10^8 , m/s ):

[ v = 0.025 \times 3.00 \times 10^8 = 7.5 \times 10^6 , m/s ]

So, the recession velocity of the distant galaxy is approximately ( 7.5 \times 10^6 , m/s ).

The measurement of the spectral line X from a more distant galaxy being at ( 6.92 \times 10^{-7} , m ) indicates an increase in red shift compared to closer galaxies. This shift implies that the galaxy is moving away from us at a faster rate than those nearby. This observation supports the notion that the Universe is expanding, as evidenced by the consistent increase in red shift corresponding to greater distances from Earth.

Telescopes on satellites benefit from several factors:

1. Reduced Atmospheric Interference: Observing from space allows telescopes to avoid atmospheric distortion and absorption, leading to clearer images.

2. Continuous Observation: Satellites can capture data continuously without the interruptions caused by day/night cycles.

3. Access to Wider Spectrum: Space telescopes can observe wavelengths of light that are absorbed by the Earth's atmosphere, enabling a broader range of astronomical observations.