Teacher notes This ordering activity could be used as a plenary or revision exercise on the lifecycle of small stars, and the difference between small stars and large stars in the following activity. Mini-whiteboards could be used to make this a whole-class exercise.

Teacher notes This ordering activity could be used as a plenary or revision exercise on the lifecycle of large stars, and the difference between large stars and small stars in the previous activity. Mini-whiteboards could be used to make this a whole-class exercise.

Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe.

What might lead scientists to question this model? Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. The Steady State Theory The Universe has always existed and always will. This is based on the fact that the Universe appears pretty much the same everywhere and always has done. The apparent expansion of the Universe is explained by suggesting that new matter is being created What might lead scientists to question this model?

Cosmic microwave background Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. Learning Objectives By the end of this lesson you should… Know the evidence that must be explained by a theory of the Universe Understand the term red shift Be able to describe the alternative theories of the Universe Three observed features of the Universe which disprove the steady state: Cosmic microwave background Light from other galaxies is red-shifted The further away a galaxy is, the greater its red-shift

In 1964, two unsuspecting scientists made a discovery so large they didn’t even realise! antenna Penzias Wilson Penzias and Wilson, two physicists from the Bell labs, who would later win the Nobel prize in 1978 for their work.

Cosmic Microwave Background Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. Cosmic Microwave Background CMB is radiation remaining from the Big Bang explosion and fills the whole of the Universe. This radiation has cooled as the Universe has expanded and is now slightly less than 3 degrees above absolute zero. Discovering about the CMB

Cosmic Microwave Background Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. Cosmic Microwave Background Where ever we look we measure the same data. So, the big-bang must have taken place at the same time everywhere. Discovering about the CMB

Look at the light coming from our Sun Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. Look at the light coming from our Sun - Use a spectroscope to view the light coming in through the window

If you pass the light through a gas something different is seen… Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. helium Some wavelengths of light are absorbed by the gas – an “absorption spectrum”.

It is red - shifted Before After Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. If the light source is moving away the absorption spectra look a little different… Before After It is red - shifted

Lets think about sound… Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. Why? Lets think about sound… What noise does a motorbike moving away from you make?

Teacher notes This four-stage animation explains the Doppler effect using sound.

The Doppler Effect Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. The Doppler Effect A B B A Source of waves is moving to the right Source of waves is stationary A hears a sound with a long wavelength (low pitch). B hears a sound with a short wavelength (high pitch) A and B hear the same sound

Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. As a car approaches us the sound waves are _________ together. We hear _____ waves per second and so the frequency is greater (_______ pitch). As a car moves away the sound waves are ________ out. We hear less waves per second and so the frequency is lower (_______ pitch).

Light sources in the Universe are moving away from each other The same happens with light waves. For a light source moving away from us we will observe longer wavelengths Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. Before After Light sources in the Universe are moving away from each other

This means the distant galaxies must be moving away from the Earth. Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. This means the distant galaxies must be moving away from the Earth. Photo credit: © 2006 Jupiterimages Corporation It has also been observed that the further away a galaxy is, the greater the amount of red shift. This means that very distant galaxies must be moving faster than near.

Light from other galaxies has a longer ____________ than expected Light from other galaxies has a longer ____________ than expected. This shows that these galaxies are moving _______ from us very quickly. This effect is seen to a greater extent in galaxies that are _________ away from us. This indicates that the further away the galaxy is, the ________ it is moving. This shifting of light towards the red end of the spectrum is called the ‘____ _____’. (Note that objects coming _______ towards us will experience a shift towards the blue end of the spectrum. This evidence seems to suggest that everything in the universe is moving away from everything else, and that this process started around 15 _____ years ago. This is the ____ ________ Theory.

Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. The Big Bang Theory About 15 billion years ago, all the matter in the Universe was compressed into a very small space and exploded. It is believed that the background radiation is a residue from the explosion.

Consequences If everything is moving away from us and things farther are moving faster Then the Universe is expanding! This doesn’t mean what you are probably thinking . . . .

Expanding Universe Space itself is expanding, not matter flying apart within space. Examples: dots rubber band raisin bread ants on a balloon It does not mean we are at the center of the Universe every part of the Universe sees everything moving away from it

The Universe from beginning to end Teacher notes This six-stage sequence introduces the different theories about the beginning and end of the Universe.

What are the possible fates of the Universe? Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. What are the possible fates of the Universe? Low mass High mass

Work through ‘The Universe’ worksheet Learning Objectives By the end of this lesson you should… State the evidence for the big bang and explain why alternative theories are insufficient. Explain what is meant by the Doppler effect Describe how the light from distant stars may be red-shifted and explain the implication of this on our understanding of the universe. HOMEWORK For next lesson Work through ‘The Universe’ worksheet

Cosmic Microwave Background Radiation (CMBR) was discovered by scientists in 1965. It is a form of electromagnetic radiation that fills the universe. Where do scientists believe CMBR came from? [1] CMBR is used to support the Big Bang theory. How does the Big Bang theory describe the beginning of the universe? [1] Red shift is a piece of evidence used to support the Big Bang theory. Explain how red shift provides evidence to support the Big Bang theory [6]