Universe Booklet. Yr10

8/4/2019 Universe Booklet. Yr10

http://slidepdf.com/reader/full/universe-booklet-yr10 1/19

Name:



Follow the step-by-step instructions…

Activity 1 - Galaxies1. Take a round balloon and draw on it six small galaxies, each about 5mm

across. Make your galaxies roughly evenly spaced around the balloon.

2. Choose any one of the galaxies, and mark it ‘Milky Way’ so that you

remember which it is.

3. Label the nearest galaxies around it A, B and C, and make a note of the

distances from this galaxy to its nearest neighbours.

Galaxy

Distance to the Milky

Way (before

expansion) /cm

Distance to the Milky

Way (after

expansion) /cm

Distance moved /cm

A

B

C

4. The balloon represents space itself.

Blow up the balloon to represent the expansion of space.

5. Again check the distances from the Milky Way to its nearest neighbours.

6. Answer the following questions (in complete sentences):

a) Sketch the balloon with its galaxies before and after you blew it up.

b) If people living somewhere in the Milky Way observe the motions of their

neighbour galaxies, what will they notice? Why might they think their own

galaxy is the centre of the universe?



c) Would people in a different galaxy observe the same overall effect, or

something different?

d) As time goes by, the real universe behaves rather like this balloon. What do

you think our astronomers must have observed about the motion of ourneighbouring galaxies?

Activity 2 - Light

When space itself expands, any light waves travelling across it become

stretched.

1. Take a balloon, and use a pen to draw a wave along it.

2. Blow up the balloon to represent the expansion of space. Observe what

happens to the wave.

3. Answer the following questions (in complete sentences):

a) Sketch the balloon before and after.

b) How did the wavelength change when you blew up the balloon?

c) This effect is called ‘redshift’, because it shifts the light from objects

towards the red end of the spectrum. Explain why.



Red Shift and the Doppler Effect

The Doppler Effect is the observed change in wavelength of a wave due to the

motion of the source relative to the observer.

When the object is moving:

This is how the waves from the object would be observed:

With sound this means that when a source is moving towards you, a higher pitch

sound will be heard because the wavelength is shortened and when a source is

moving away from you, a lower pitch sound will be heard because the wavelength

is longer. You can hear this effect in the DOPPLER BALL DEMONSTRATION.

With light we call this effect red shift and we can observe redshift by

looking at the spectrum of light given off by astronomical objects.

The waves behind the object

get ‘stretched out’ so the

wavelength increases.

The waves in front of the

object get ‘squashed together’

so the wavelength decreases.



Red Shift

The spectrum from stars for example will have dark line appearing in them. These dark linesindicate what elements the star is composed of e.g. Hydrogen. So, since the Sun is so close to

use we can consider it to be stationary. So we can compare the dark lines from other objects to

the sun’s spectrum. If these dark lines are more towards the red end of the spectrum, then we

say that the light has been red shifted and the object is moving away from us. If the line is

towards the violet end then we say the light has been blue shifted and the object is moving

towards us.

In astronomy the Doppler Effect is used to measure the motion of the galaxies.

The faster a galaxy moves the greater the red shift will be.

Sun’s

spectrum

Another

star’s

spectrum

Shifted towards the red

end

Violet Red

Everywhere we look galaxies are red shifted!

This was discovered by a good looking, pipe smoking American Astronomer

called Edwin Hubble in 1929 (pictured right).This tells us that nearly all other galaxies are moving …………… from us!

Hubble also noticed that the further away the galaxy, the greater its red shift and therefore the

……………. it is moving

In fact the speed a galaxy is moving is directly proportional to its distance from us



Speed of Galaxy(m/s)

Distance from us, (m)

We call the constant that relates thedistance to the speed of a GalaxyHubble's constant! Velocity = Hubble's Constant x Distance

Extra Info: Just for your enjoyment!



The Big Bang Theory

To explain Hubble’s extraordinary discoveries about our expanding universe,

astronomers came up with the Big Bang Theory. The Big Bang theory states that

the whole universe started from a single tiny point that expanded rapidly in an

explosion about 13 Billion years ago and is still expanding today (like the surface

of a balloon, all galaxies are moving apart from each other, there is no centre!).Matter was thrown out in all directions forming stars and galaxies. Both Space

and time were created in the Big Bang.

However the Big Bang theory had some competition…

There are 2 main theories about the Universe.

The Big Bang Theory - All matter and energy in the entire universe and the

four dimensions of time and space, were created in an explosion from a single

tiny point about 14 billion years ago.

The Steady State Theory - The universe on a large scale does not change with

time (evolve). It has always existed and will always continue to exist looking

much as it does now. The density of the universe remains the same because as

the universe expands matter is continuously being created to fill the gap.

Questions

1. What is the main difference between the Big Bang Theory and the Steady

State Theory?

Complete the table on the following page

2. Which theory are Scientists more likely to believe?

3. Why?



Evidence for the Big Bang

Evidence How does this support the

Big Bang Theory?

How does this support

Steady State theory?

Red Shift

Cosmic Microwave

Background Radiation

Some challenging extension ideas…

Olbers

Paradox

The HubbleDeep Field

Abundance of Elements

The End of the Universe?

So we now think it all started with a big bang! But how will it all end? There are 2 different ideas and which one

will happen depends on how dense the Universe is. If there is there is over a certain amount of mass per bit of

space then gravity will slow the expansion and slowly drag everything back together into a “Big Crunch”. If thereis not enough mass then the Universe will continue to expand forever, everything will slowly get spread out and

the Universe will die in a “Big Yawn”!

Astronomers are trying to solve how much mass is in the Universe as we speak!



Telescopes compared

Type of radiation What it can see Other information

Radio telescopes

Microwave telescopes

Infra red telescopes

Reflecting telescopes &

Refracting telescopes using

visible light

Ultraviolet telescopes

X-ray and Gamma raytelescopes



Wavelength: __________________ Frequency: __________________

Pitch: __________________

Wavelength: __________________ Frequency: __________________

Pitch: __________________

Doppler Effect _________ Shift _________ Shift

Far away galaxy Nearby galaxy

Motion

Questions: Some of Anthony’s friends pass him in a car as he walks along the pavement. As a friendly gesture they

continuously beep their horn as they pass him. The frequency of the horn is 80Hz.

a. How does the pitch of the horn sound as the car travels towards him?

b. How does the pitch of the horn sound as the car travels away from him?

c. What is this effect called?

d. Calculate the wavelength of the sound wave produced by the horn (the speed of sound in air is 330m/s).

e. Would you expect the value of the wavelength to be less than or greater than this as the car is travelling

towards him?

f. Sketch a graph of frequency against time to show how the frequency of the horn changes as the car passes

Anthony.

g. Sketch on the same set of axes a second line to show how the frequency would change if the car were travelling

faster.



Wavelength: __________________

Frequency: __________________

Electromagnetic Spectrum

Wavelength: __________________

Frequency: __________________

Tasks

Completing the first box

• Using your knowledge of the electromagnetic spectrum fill in the little boxes with the names of the

electromagnetic spectrum. (Look carefully at the diagram to help you)

• Complete the blanks showing whether the frequency is high/low or weather the wavelength is long/short for the

EM spectrum

(Frequency shows the number of waves per second and the wavelength shows the length between each ‘crest’)

Completing the second box

• To complete this box you will need a blue and red pen

• Using the knowledge that you have obtained describe how the frequency, wavelength and pitch changes for an

object/galaxy moving towards us using a blue pen

• Using the knowledge that you have obtained describe how the frequency, wavelength and pitch changes for an

object/galaxy moving away from us using a red pen

• Using the correct coloured pen colour in each wave and say whether the diagram shows a red/blue shift



1. Scientists have a theory that the universe began with a massive explosion.

What do you think scientists would do if new evidence were found that did not support this

theory? Put a tick ( ) in the box next to your answer.

A – ignore the evidence

B – change the theory straight away

C – check the evidence to make sure it is reliable

(1)

2. Light is given out by both the Sun and a distant galaxy.

(a) Compared to the light from the Sun, the light from the distant galaxy has moved towards the

red end of the spectrum.

(i) What name is given to this effect?

..........................................................................................................................

(1)

(ii) Complete the following sentence by ticking the box that is correct.

The fact that light from a distant galaxy seems to move towards the red end of the

spectrum gives scientists evidence that:

galaxies are shrinking

galaxies are changing colour

the universe is expanding

(1)

(b) Scientists have a theory that the universe began from a very small point and then exploded

outwards.

(i) What name is given to this theory?

..........................................................................................................................

(1)

(ii) Which statement gives a reason why scientists think that the universe began

with an explosion? Put a tick ( ) in the box next to your choice.

At the moment it is the best way of explaining our scientific knowledge.

It can be proved using equations.

People felt the explosion.

(1)

(Total 5 marks)



3. The diagrams show the line spectrum emitted by two galaxies. Both galaxies are movingaway from Earth.

a How do you know that the galaxies are moving away from us?

______________________________________________________________ (1)

b Which galaxy, A or B, is moving away faster?

Give one reason for your choice.

______________________________________________________________ (1)

c What does this tell you about how far away the two galaxies are?

______________________________________________________________ (1)

The table below gives the velocity and distance for a number of different galaxies:

ConstellationDistance, d

in millions of light years

Velocity, v , of a galaxyin the constellation

in km/s

Virgo 72 1 200

Perseus 400

Ursa Major 900 15 000

Corona Borealis 1200 20 000

Hydra 60 000

Hubble’s Law states that v=Hd where H is the Hubble constant.

d Use the table to find a value for the Hubble constant, H. (1)

e Find the velocity of the Perseus galaxy. (1)

f Find the missing information for the Hydra galaxy. (1)



4. When excited, hydrogen gas emits a spectrum of electromagnetic radiation of several different

wavelengths. When measured in a laboratory on Earth one of these wavelengths is measured as

656.3nm. A physicist observes several different galaxies through a telescope and measures the

wavelength of the same part of the spectrum. He tabulates his results in the table below.

Galaxy Wavelength /nm

A 656.5

B 657.0

C 656.6

D 658.2

E 660.0

F 656.0

a. What region of the electromagnetic spectrum does this region of the hydrogen spectra belong to?

(1)

b. Explain which galaxy has the greatest speed (use the term red shift in your answer)?(1)

c. Explain which galaxy is closest to the Milky Way (use the term red shift in your answer).

(2)

d. One of the results contradicts our current understanding of the universe. Which one and why?

(2)

e. What should the physicist do with this result?

(1)

5. In 1965 Arno Penzias and Robert Wilson discovered the presence of Cosmic Background Radiation

(CBR) – radiation from all directions that corresponds to a body of temperature 2.7°C above absolute

zero.

a. At what time was the radiation thought to have initially been created?

(1)

b. To what region of the electromagnetic spectrum does CBR now belong?

(1)

c. To what region of the electromagnetic spectrum does CBR initially belong?

(1)

d. Why did CBR belong to a different region of the electromagnetic spectrum in the early stages of

the universe?

(2)

(Total 12 Marks)



6. The ‘steady state’ theory was once a popular alternative to the ‘big bang’ theory.

The ‘steady state’ theory suggested that the universe, although expanding, had no origin and it has

always existed. As the universe expands, a small amount of matter is created to keep the universe

looking exactly the same all of the time.

(a) When considering the origin of the universe, what is the difference between the ‘big bang’

theory and the ‘steady state’ theory?

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

(2)

(b) The light from distant galaxies shows a red-shift .

(i) What is red-shift ?

...........................................................................................................................

...........................................................................................................................

(1)

(ii) Why does red-shift provide evidence to support both the ‘big-bang’ theory and the

‘steady state’ theory?

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

(2)

(c) The ‘steady state’ theory was important in encouraging new research into the universe.

Suggest a reason why scientists were keen to carry out new research.

.....................................................................................................................................

.....................................................................................................................................

(1)

(d) Scientists can answer many questions about the universe, but not the question:

‘Why was the universe created?’

Suggest a reason why scientists cannot answer this question.

.....................................................................................................................................

.....................................................................................................................................

(1)

(Total 7 marks)



Using telescopes to look into space

We can see even more in the night sky with a telescope. Telescopes collect more light than

our eyes and can magnify the images they collect. This means they can see further into space

and get more detailed images. Telescopes can be placed either on the ground or on satellites.

The images collected by ground-based telescopes tend to be quite fuzzy because the Earth’s

atmosphere dims, scatters and distorts the light. It is however very expensive to put

telescopes on satellites in space.

Telescopes can be designed to detect any type of electromagnetic wave. This advance in

technology has allowed astronomers to generate images of objects in space from the visible

light, infra-red, radio waves, X-rays and any other electromagnetic waves they emit.

Astronomers have learnt a great deal about the Universe from these images. However, not

all electromagnetic waves can penetrate the Earth’s atmosphere. This means telescopes that

detect certain electromagnetic waves must be placed in space. Each type of telescope has

its’ own strong and weak points.

Making telescopes

It is possible to make a simple refracting telescope with two lenses as shown below:

Try it out and see what you can see…

When we look into the night sky, we sometimes see unexpected objects as well

as planets and stars. Such objects include:

• Shooting stars which are small objects from space that burn up when

they enter the Earth’s atmosphere

• Comets which are frozen rocks that orbit the Sun

• Stars that explode (supernova)



Comparing telescopes on Earth and in space

Sort the cards into advantages and disadvantages of Earth and Space based telescopes and

write the points into the correct boxes:

D i s a

d v a n t a g e s

A d v a n t a g e s

Space basedEarth based



Telescope questions

1. Why can telescopes see further into space and get more detailed images of the Universe?

…………………………………………………………………………………………………………………………………………………………………………

2. Why is better to place telescopes on a satellite in space rather than placing them on the

ground?……………………………………………………………………………………………………………………………………………………………………………

3. There are two main disadvantages of putting telescopes on satellites. One is written in the

text on the previous page, the other isn’t.

a) What is the disadvantage mentioned in the text?

………………………………………………………………………………………………………………………………………………………………

b) What do you think the other disadvantage is?

………………………………………………………………………………………………………………………………………………………………

Use the tables below to answer the remaining questions.

Telescope Type of electromagnetic

radiation detected

Electromagnetic

radiation

Does it penetrate the Earth’s

atmosphere?

Hubble Visible light Gamma waves Stopped 50km above Earth’s surface

Jodrell Bank Radio waves X-rays Stopped 200km above Earth’s

surface

Compton Gamma waves Visible light Yes

Spitzer Infra-red Infra-red Only shorter wavelengths

Chandra X-rays Radio waves Yes

4. Which two telescopes could be ground-based? Why?

……………………………………………………………………………………………………………………………………………………………………………5. Which telescopes must be placed on a satellite? Why?

……………………………………………………………………………………………………………………………………………………………………………

………………………………..…………………..…………………………………………………………………………………………………………………….

6. The Hubble telescope is placed on a satellite in space despite the fact that visible light can

penetrate the Earth’s atmosphere. Why do you think astronomers chose to do this?

……………………………………………………………………………………………………………………………………………………………………………

……………………………………………………………………………………………………………………………………………………………………………

Universe Booklet. Yr10

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