Red-shift and the expanding universe

Telescopes are used to observe distant objects.

Complete the sentences.

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What is the name of our galaxy?

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The Sun is our nearest star.

What will happen to the Sun at the end of its life cycle?

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The James Webb Space Telescope is the most powerful telescope ever launched into space.

Very distant galaxies can be observed using the James Webb Space Telescope.

How does the speed of a very distant galaxy compare to the speed of a much nearer galaxy?

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There is an observed increase in the wavelength of light from most distant galaxies.

What name is given to this increase in the wavelength of light?

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Observations from the James Webb Space Telescope support the Big Bang theory.

Complete the sentence.

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The Big Bang theory suggests that the universe began from a region that

What does the Big Bang theory suggest is happening to the size of the universe?

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Telescopes are used to look at distant objects.

Some telescopes use lenses to form an image.

Figure 5 shows two parallel rays of light incident on a lens in a telescope.

The principal focus of the lens is labelled F.

What type of lens is shown in Figure 5 ?

Complete the ray diagram in Figure 5.

The James Webb Space Telescope can detect electromagnetic radiation beyond the visible spectrum.

The shortest wavelength of electromagnetic radiation that can be detected by the James Webb Space Telescope is 0.60 m.

speed of electromagnetic radiation = 3.0 × 10⁸ m/s

Calculate the frequency of electromagnetic radiation that has a wavelength of

Use the Physics Equations Sheet.

Complete the sentence.

Electromagnetic radiation detected from distant galaxies is red-shifted.

This means that the electromagnetic radiation shows an increase in

Why is the electromagnetic radiation from distant galaxies red-shifted?

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The James Webb Space Telescope has detected electromagnetic radiation from many different galaxies.

Electromagnetic radiation from one of the galaxies detected shows the greatest red-shift ever observed.

What conclusion can be made about the distance to this galaxy?

The James Webb Space Telescope is an artificial satellite that orbits the Sun at a constant speed.

Explain why the velocity of the satellite changes as it orbits the Sun.

The Universe contains many stars.

The Sun is the star at the centre of our solar system.

Give three other types of object that form our solar system.

Some main sequence stars will eventually form black holes.

Table 3 gives the mass of four stars.

Which star in Table 3 is most likely to form a black hole?

The distance from Cygni A to the Earth is 1.1 × 10⁸ gigametres.

Which distance is the same as 1.1 × 10⁸ gigametres?

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The light spectrum from every galaxy includes dark lines.

The lines have the same pattern.

Figure 7 shows the position of dark lines in the visible spectra of light from the Sun and from two distant galaxies.

Explain what these light spectra tell us about the velocities of galaxy A and galaxy B.

The distance between Arcturus and the Earth is 3.6 × 10¹⁴ km.

Calculate the time taken for light from Arcturus to reach the Earth.

Use the Physics Equations Sheet.

When stars are formed, they contain mostly hydrogen.

Describe how stars produce all other naturally occurring elements.

Figure 17 shows the Hubble Space Telescope orbiting the Earth.

What name is given to an object that orbits a planet? Tick (✓) one box.

The Earth exerts a gravitational force on the Hubble Space Telescope. Draw an arrow on Figure 17 to show the gravitational force.

Figure 18 shows how the distance travelled by the Hubble Space Telescope during its orbit changes with time.

The gradient of the line in Figure 18 gives the speed of the Hubble Space Telescope. Determine the speed of the Hubble Space Telescope. Give your answer in km/s.

The Hubble Space Telescope can detect the visible light spectra from distant galaxies. The visible light spectra from stars and galaxies include dark lines at specific wavelengths. Figure 19 shows the visible light spectra from the Sun and three galaxies.

Which galaxy is moving away from the Earth the fastest? Tick (✓) one box.

Which galaxy is the furthest away from the Earth? Tick (✓) one box.

New scientific observations indicate that many galaxies rotate too quickly for the known mass of the stars they contain. Why is it important that new scientific observations are peer reviewed? Tick (✓) one box.

Figure 15 shows the Hubble Space Telescope orbiting the Earth.

What name is given to objects that orbit a planet?

A space telescope uses microwaves to communicate with the Earth. A microwave has a wavelength of 12.5 cm. The speed of microwaves through space is 3.0 × 10⁸ m/s. Calculate the frequency of the microwave. Use the Physics Equations Sheet. Give your answer in standard form.

Explain the effect of the Earth’s gravitational force on the motion of the Hubble Space Telescope.

The Hubble Space Telescope can detect visible light from distant galaxies. The visible light spectra from stars and galaxies include dark lines at specific wavelengths. Figure 16 shows the visible light spectra from the Sun and two galaxies.

Explain what conclusions can be made about galaxies A and B.

Galaxies contain billions of stars.

Compare the formation and life cycles of stars with a similar mass to the Sun to stars with a much greater mass than the Sun.

The points on Figure 11 represent galaxies that are moving away from the Milky Way.

Each arrow represents the velocity of the galaxy relative to the Milky Way.

Light from all galaxies represented in Figure 11 is red-shifted.

Describe what is meant by red-shift.

Explain how Figure 11 provides evidence for the Big Bang theory.

Sometimes scientists have to change theories about the universe.

Give the reason why.

A main sequence star in a distant galaxy is the same size and mass as the Sun.

Explain why the star is stable while it is in the main sequence stage of its life cycle.

Describe what will happen to the star between the main sequence stage and the end of the star’s life cycle. You should include the names of the stages in the life cycle of the star.

Figure 5 shows how the speed of galaxies moving away from Earth varies with the distance of the galaxies from Earth.

Which galaxy would show the smallest observed change in the wavelength of visible light? Give a reason for your answer. Tick (✓) one box.

Most galaxies are moving away from the Earth. Scientists can determine the speed of a galaxy by observing the light from the galaxy.

Complete the sentence. Choose the answer from the box.

When scientists observe the light from distant galaxies, they observe an increase in the of light from those galaxies.

The light spectra from stars and galaxies include dark lines. The lines have the same pattern. Figure 3 shows the light spectrum from the Sun and from four galaxies.

Which galaxy is moving the fastest away from the Earth? Tick (✓) one box.

Which galaxy is the furthest away from the Earth? Tick (✓) one box.

The Big Bang theory is one way to explain the origin of the universe. How does the Big Bang theory describe the universe when it began?

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Which statement about the Big Bang theory is correct? Tick (✓) one box.

Figure 4 shows three ways that the size of the universe may have changed with time.

Figure 4

Which graph would the Big Bang theory suggest is correct?

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Give a reason for your answer.

The light from distant galaxies shows red-shift. Complete the sentence.

The term red-shift describes the observed increase

The Big Bang theory is one model used to explain the origin of the universe. How does the Big Bang theory describe the universe when it began?

Figure 9 shows data scientists have calculated from measurements of red-shift.

Describe the relationship between the speed of a galaxy and the distance the galaxy is from the Earth.

Which of the following is the same as 6 x 10¹² terametres? Tick (✓) one box.

Explain how the data in Figure 9 supports the suggestion that the universe began from a very small region.

The Big Bang theory suggested that gravity would slow the rate at which galaxies move away from the Earth. New observations suggest that distant galaxies are moving away from the Earth at an increasingly fast rate. What do the new observations suggest is happening to the universe?

New observations and data that do not fit existing theories should undergo peer review. Give one reason why peer review is an important process.

The Andromeda galaxy is moving towards the Earth. Describe how the wavelength and frequency of the light from Andromeda seem to have changed when viewed from the Earth.