1. Doesn’t that mean we are in the centre of the universe?
So…
If every distant galaxy is moving away from us, and the further the galaxy is from us, the faster it is moving away from us….
Doesn’t that mean we are in the centre of the universe?
True?

2. Learning Objectives
By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)

3. Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Consequences
Red-shift tells us all galaxies (i.e everything) is moving away from us and things farther away are moving faster than those close…
The Universe is expanding!
BUT this probably doesn’t mean what you are thinking

4. Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Expanding Universe
Firstly space itself is expanding, not the matter flying apart within space.
Examples:
dots
rubber band
raisin bread
ants on a balloon

5. Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Expanding Universe
Secondly it does not mean we are at the center of the Universe;
Every part of the Universe sees everything moving away from it!

6. Evidence for the Big Bang
Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Evidence for the Big Bang
Not actually limited to just red-shift BUT AQA only require you to know this one idea…
We, your physics teachers, would like you to know more however!

7. Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Evidence for the Big Bang includes:
Spectra from galaxies shows a shift to longer wavelengths (i.e. they are moving away from the Earth)
The more distant galaxies are moving away faster
Existence of microwave background radiation which is the same in all directions (uniform intensity) which formed when matter and radiation decoupled. Was originally gamma and now microwave (temp = 2.7K).
There is more helium (primordial helium) in the universe than would have been produced by stars alone.

9. The CMBR
The Big Bang Theory of the Universe suggests that the initial hot plasma of the early Universe would cool as the it expanded.
Calculations suggest that a background radiation would exist at a few degrees Kelvin – Exactly what the scientists found

10. What will the universe be like in another 14 billion years?
Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
What will the universe be like in another 14 billion years?

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

12. Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Future of the Universe
The future of the Universe is uncertain mostly because the precise mass of universe is unknown.
This is a big problem for physicists as the universe has one of three likely futures each of which depends on the mass;
Continue to expand forever, matter becomes further and further apart.
The Big Crunch, galaxies stop accelerating away from each other and contract inward.
“Flat Universe”, stops expanding but does not contact inwards.

13. Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Future of the Universe
Which one of these futures would be most likely for a high mass Universe? What about a low mass?
Continue to expand forever, matter becomes further and further apart.
The Big Crunch, galaxies stop accelerating away from each other and contract inward.
“Flat Universe”, stops expanding but does not contact inwards.

14. Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Dark Energy and Dark Matter
In 2011 Perlmutter, Schmidt and Reiss were awarded the Nobel Prize for their observations of a type 1a Supernova.

15. Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Dark Energy and Dark Matter
The supernova is used as a standard candle in astronomy and should be of a fixed brightness. More distant supernovas were noted as being less intense than they should be. This could only be explained if the rate of expansion of the Universe was increasing. Dark energy has been hypothesised to provide this accelerating force. Pretty much everything else about dark energy is unknown!

16. Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Dark Energy and Dark Matter
Another problem that has faced astronomers is why galaxies rotate at the speeds they do. Stars located away from the galactic centre should rotate more slowly (like Uranus does around the Sun) but this was not found to be true. The observation suggested there was matter spread throughout the galaxy which could not be seen! Dark matter is used to explain this mass deficit and is conjectured to exist uniformly across all of space. It is hypothesised to be up to 27% of all matter in the Universe!

17. Specification Aims By the end of this lesson you should be able to…
Describe some of the key ideas behind The Big Bang theory and how the universe began.
Explain how scientists are able to use observations from space to arrive at theories such as the Big Bang theory.
Recall some of the unknowns which still exist in cosmology. (isn’t that great? The learning objective is to NOT know something?!)
Dark Energy and Dark Matter
Dark energy and Dark Matter in a nutshell
Empty space isn’t empty!?
Misconceptions about the Universe