science gcse core, additional and triple science powerpoints

1. P1.4 Mapping the seafloor P1.6 Earthquakes and volcanoes P1.10 Are we alone ? P1.11 The Great Debate of 1920 P1.12 How did the Universe begin ? P1. The Earth in the Universe Route map Over the next 12 lessons you will study : Friday 21 October 2011 P1.1 Time and space P1.2 Deep time P1.3 Continental drift P1.5 The theory of plate tectonics End of module test P1.9 What are we made of ? P1.7 The Solar System- danger ! P1.8 What killed off the dinosaurs ?

3. P1.7 The Solar System- danger! Extension questions: 1: Explain why many of the impact craters on the moon are very visible whereas here on Earth there are more difficult to find ? 2: What method can be used to tell the age of minerals and rocks found in asteroids ? 3: Why do you think the first scientists thought craters were formed by volcanoes ? 4: In your opinion, what causes more damage during impact on Earth's surface, an asteroid, a comet or a meteorite ? Know this: a: Know that craters are caused by the violent impact of an asteroid on the Earth’s surface. b: Know that at several times during Earth’s history, a massive asteroid or comet has struck causing mass extinction events. Friday 21 October 2011 Introduction: Scientist are interest in both the material found in comets and asteroids. Comets are lumps of rock held together by ice and frozen gases and they orbit the Sun. Scientists have recently sampled the material in a comets tail to better understand the material used to build stars, planets and even whole galaxies Asteroids are lumps of rock that are much smaller than planets. Most asteroids orbit the Sun between the orbits of Mars and Jupiter, but a few cross the Earth’s path. There is a tiny risk that one of these asteroids will collide with the Earth. Asteroid impact the Earth's surface throughout its history, some causing huge climate changes leading to mass extinct events

4. Key concepts P1.7 a Look at the photograph and information and answer all the questions: Order the following with smallest first meteorite, micro-meteorite, comet and asteroid ? Look at the dates for the asteroid strikes listed in the table above right. Which asteroid strike is associated with the mass extinction of the dinosaurs ? Geologist all over the globe have studied not only the size and depth of craters formed by incoming asteroids but also the type of minerals and rocks found around the impact site. These crater sites tend to be rich in rare metals like iridium which is only found in very small quantities elsewhere in the Earth’s crust. By studying the age of the minerals and their composition we can determine what asteroids contain and when they impacted on Earth’s surface . Craters found on the Earth's surface Name Diameter 1 Age 2 Barringer, USA 2 0.05 Chicxulub, Mexico 175 65 Silverpit, North sea 5 60 Aorounga, Chad 20 350 Sudbury, Canada 255 1860 1 Diameter (km) 2 Age (million of years) Barringer crater, USA

5. P1.7 b Look at the photograph and information and answer all the questions: Why is the surface of the moon good evidence that the Earth was hit by many asteroids in its past ? The moon’s surface is covered in craters, which element would you find around these cater impact sites ? The moon, devoid of an atmosphere, surface running water and a molten core does not have a rock cycle and therefore no rock weathering processes. Craters formed by colliding asteroids are perfectly preserved over millions of years. Looking at the moon’s surface you can begin to appreciate that the moon and the Earth must have been hit many thousands of times by incoming asteroids of various sizes. Could one of these impacts in our own history have cause the mass extinction of dinosaurs and other species about 65 million years ago ? Craters found on the Moon's surface Key concepts

6. P1.7 Plenary Lesson summary: moon dwarf craters lump Friday 21 October 2011 One of the very well preserved Asteroid craters that remains well preserved is the Barringer crater located in the Arizona desert USA. It is over 200 metres deep and nearly 2 kilometres in diameter. The reason why it is well preserved despite being over 500,000 years old is that is in the desert no water supports plant life and water erosion. How Science Works: Research into how scientists have linked the impact of an asteroid that formed the Chicxulub crater 65,000,000 years ago and the mass extinction of the dinosaurs. Preparing for the next lesson: An asteroid is a _____ rocky planet that generally orbits the Sun between the orbits of Mars and Jupiter. A comet is a rocky _____ held together by frozen gases and water and orbits the Sun. _______ are formed when an asteroid collides violently with a planet or a _____. Decide whether the following statements are true or false : False True 3: Scientific papers and conferences make scientific knowledge less reliable ? False True 2: Meteorites are large grains of dust that travel at very slow speeds ? False True 1: Asteroids are smaller than comets which in turn are smaller than meteorites ?

8. P1.8 What killed off the dinosaurs ? Extension questions: 1: Of the two explanations given above, which do you think is most likely and why ? 2: Rocks formed 65 million years ago contain iridium. Why is this important in the validation of the asteroid theory ? 3: Why is there so much uncertainty about what happened to the dinosaurs ? 4: How do fossil record help scientists build up a pictured of what species became extinct and which new species appear from 65 million years ago to the present day ? Know this: a: Know the effects of an impacting super asteroid here on the Earth’s surface. b: Know that a possible explanation for the mass extinction of dinosaurs is a violent asteroid strike that occurred around 65 million years ago. Friday 21 October 2011 Introduction: What caused the mass extinction of dinosaurs is something that scientists cannot yet agree about. It is still an area of scientific uncertainty. One explanation is that an asteroid hit the Earth 65 million years ago and caused the mass extinction of dinosaurs. But there are two problems with this explanation. The first being that dinosaurs had already started to die out before the asteroid struck and the second that other major impacts did not have such an effect. Another explanation is an enormous eruption from a super-volcano. But other such eruptions have not had the same effect on extinction rates.

9. P1.8 a Look at the photograph and information and answer all the questions: There have been periods in the earth past which has seen large number of species become extinct as a result of changing environments. In modern times the primary contributor to extinctions is man because our use of natural resources and the destruction of natural habitats like the tropical rain forest. What event caused the extinction of the dinosaurs around 65 million years ago ? It is said that small mammal replaced the dinosaurs on land. Why was this important for our own evolution in time ? Man’s activities causes most extinctions now. Explain three things that we do that may endanger animals or plants ? Key concepts

10. P1.8 b Look at the photograph and information and answer all the questions: What happens to a) average global temperatures, b) number of organisms following the asteroid strike 65.1 million years ago ? What would have happened to the food chain following cooler temperature and reduced sunlight ? pressure extinction Extinction of the dinosaurs The mass extinction event that occurred some 65 million years ago out more than half of all species on the planet, including the dinosaurs, clearing the way for mammals to become the dominant species on Earth. The review of the evidence shows that the extinction was caused by a massive asteroid or comet smashing into Earth at Chicxulub on Mexico’s Yucatan Peninsula. When the15km space rock struck the Yucatan, the explosive energy released was equivalent to 100 trillion tonnes of TNT – Asteroid collision Low sunlight Low temperatures Failed food chain Key concepts

11. P1.8 Plenary Lesson summary: India Mexico cooling iridium Friday 21 October 2011 Although the mass extinction of dinosaurs witnessed huge numbers of species disappeared off the planet’s surface, small mammals at this time thrived. With less competition for resource like food shelter and space this group of mammals eventually through evolution allowed the appearance of primates and then Man. How Science Works: Research into what starts are made of and how other elements (other than hydrogen) are formed during a start’s life cycle through nuclear fusion. Preparing for the next lesson: The dinosaurs died out at about the same time a large crater was made in ______. The asteroid strike would have created dust, containing ______, that blocked out the Sun therefore disrupting the World’s food chain. Super volcanic eruptions across _____ could also have killed the dinosaurs by _______ the Earth’s climate. Decide whether the following statements are true or false : False True 3: There is no proof that dinosaurs ever walked the Earth ? False True 2: One theory is an eclipse of the Sun that lasted for almost a year ? False True 1: Scientists agree about what caused the mass extinction of dinosaurs ?

13. P1.9 What are we made of ? Extension questions: 1: Explain how light spectra data can give scientists a picture of what each star contains ? 2: Explain how helium is made form hydrogen atoms inside a star ? 3: Is it correct to say that the Sun is a ball of gas on fire ? If yes, why? If no, why? 4: Explain how new and heavier elements are formed form hydrogen and helium atoms. 5: Explain the life cycle of a star and why all life end when our own sun becomes a red giant in 4.5 billion years time ? Know this: a: Know what elements fuel an average star through its life cycle are made of stardust. b: Know that all other elements are formed from the continuous fusion of hydrogen atoms to make heavier and heavier elements. Friday 21 October 2011 Introduction: The Sun is a star at the centre of the Solar System. It will probably shine for another 5000 million years. A star is a ball of hot gases, mainly hydrogen. The nuclei of the hydrogen atoms join together (fuse) to make helium nuclei. This is the source of the stars’ energy. Stars change over time- they have life cycles. The most common element in the Universe is hydrogen. In stars, fusion continues to make heavier and heavier elements. When fusion stops, big stars explode as supernovae. Their debris containing all 92 elements is scattered through space. Except for hydrogen and helium all the elements that make everything on Earth come from stars. We are made of stardust.

14. Key concepts P1.9 a Look at the photograph and information and answer all the questions: Scientists believe that in the early Universe only hydrogen existed. Explain how other elements have formed ? Explain why and how all life will eventually end here on planet Earth ? The Sun has a lifespan of about 9 billion years and is already halfway through its life using up to 300,000 tonnes of hydrogen gas every second. Eventually, when all the hydrogen and helium is consumed, the Sun will rapidly expand forming a red giant that engulfs and scorches the first four planets including Earth. What follows then is its contraction, the formation of a white dwarf and then a neutron star. During this phase heavier elements are formed. The life cycle of an average star like our sun Stellar nebula Average star Red Giant Planetary nebula White Dwarf Neutron star 4.5 billion years B.C 4.5 billion years A.D 4.6 billion years A.D

15. P1.9 b Look at the photograph and information and answer all the questions: Billions of stars, found in millions of galaxies, but how do we identify groups of similar stars ? The new system reordered the classes into the order OBAFGKM where O stars are the hottest and each successive class is cooler with M being the coolest stars. Each letter was also divided into tenths of the range by adding a number 0-9 to the end. O stars are the least common and M are the most common found in the main sequence of stars. Look at the above diagram, estimate the surface temperature of our own star, the sun ? Explain why larger or brighter stars often only last a few million years when compared to an average star like our own sun ? Key concepts Type Colour Temp. Range % of stars Examples O Blue-violet >30,000 K 0.00003% Stars of Orion’s Belt B Blue-white 10,000 K - 30,000 K 0.13% Rigel A White 7,500 K - 10,000 K 0.6% Sirius F Yellow-white 6,000 K - 7,500 K 3% Polaris G Yellow 5,000 K - 6,000 K 7.6% Sun K Orange 3,500 K - 5000 K 12.1% Arcturus M Red-orange <3,500 K 76.5% Proxima Centauri

16. P1.9 b Look at the photograph and information and answer all the questions: Explain why the most common element found in the Eagle nebula is hydrogen gas which is the building material for all stars ? Explain why larger or brighter stars often only last a few million years when compared to an average star like our own sun ? Billions of stars, found in millions of galaxies, filling billions of light years of space, but how are galaxies and stars formed. In 1998, the Hubble telescope and one of its many images, finally gave us spectacular evidence that tells scientists how stars and galaxies are formed. The Eagle nebula (pictured below) is a cloud of hydrogen and dust millions of light years across. At the end of each finger like protrusion, the gravitational forces form a ball of hydrogen. Huge gravitational forces superheat the hydrogen so that nuclear fusion begins, light is produced and a star is born. Key concepts

17. P1.9 Plenary Lesson summary: hydrogen giant fusion elements Friday 21 October 2011 Imagine living on Earth about 4.5 billion years into the future, you will see in the morning sky the sun turn red increasing rapidly in size. Eventually the red giant will increase and engulf even our planet instantly vapourise any surface life and water. What will be left will be a rocky planet devoid of any life and of course a cold planet without a sunrise or sunset . How Science Works: Research into other stars in our own Galaxy like Alpha Centauri and the search for extra terrestrial life (SETI) Preparing for the next lesson: Everything across the entire Universe is made from just 92 different types of atoms know as the _________. ________ is the simplest of these elements which can formed heavier elements inside starts during nuclear _______.When starts exhaust their hydrogen and helium fuel they expand forming a red ______. Decide whether the following statements are true or false : False True 3: All starts use hydrogen as their fuel releasing vast amount of energy ? False True 2: The sun’s consume about 300,000 tones of hydrogen every second ? False True 1: Nuclear fusion is when atoms come apart ?

19. P1.10 Are we alone ? Extension questions: 1: Define what a light year is and how far does light travel in a) one second and b) one week and c) one year ? 2: What is an exo-planet and why are scientists interested in locating them ? 3: Explain how you can use ‘apparent brightness to work out the distance between Earth and a star in our own galaxy the Milky Way ? 4: How many stars are there in a typical galaxy ? 5: Why is life likely to exist elsewhere in our Universe and why may we never know about its existence ? Know this: a: Know how to calculate distance between planets and stars. b: Know that SETI is a project designed to collect data or evidence showing evidence of life elsewhere in the Universe. Friday 21 October 2011 Introduction: Scientists can learn about stars and galaxies only by studying the radiation they emit. They measure the distance to stars by looking at their relative brightness or by parallax. Scientists measure distance in space in light-years. One light-year is the distance light travels in one year. There are many stars in the Universe and because of this astronomers think it is likely there may be life elsewhere in the Universe. The SETI (Search for Terrestrial Intelligence) project looks for radio signals that might be produced by aliens. So far there is no evidence of life elsewhere.

20. Key concepts P1.10 a Look at the photograph and information and answer all the questions: Why are scientists interested in knowing the distance between planet Earth and stars found in our own galaxy the Milky Way ? Our closet star is called Alpha Centauri which is 4.22 light years away. How old were you when light reaching now left Alpha Centauri ? Using the Parallex method, when the Earth moves form one side of the sun (June) to the other (December) every six months. When seen through a telescope based here on Earth, a nearer star will shift its position against the position of a more distant star. The nearer the star the greater the shift. Scientists can therefore work out using this method how far away each star in the night sky is from planet Earth . Calculating star distances using parallax method Earth in June Earth in Dec. nearer star distant stars sun

21. Key concepts P1.10 b Look at the photograph and information and answer all the questions: Why is this method less accurate than the parallax method of determining the distance between Earth and stars found in our own Galaxy ? If a star in the night sky had an exoplanet orbiting it what method could you use to prove its existence ? Using the star brightness method, when you look out to the night sky you may see up to 2000 stars. Scientists determine what kind of star they first are (its composition, size and surface temperature) by using light spectra data and then using its ‘apparent brightness’ scientists then estimate its distance from planet Earth. The nearer the star the brighter it will appear when compared to similar starts at different distances in the night sky. Calculating star distances using the star brightness method sun Earth

22. P1.10 c Look at the photograph and information and answer all the questions: As well as observing natural radio emissions from space, radio telescopes can be used to search for extraterrestrial intelligence. The search for these signals is called the SETI project. Astronomers also use telescopes that detect infrared and ultraviolet, but the telescope itself has to be in space, outside the Earth’s atmosphere. What do scientists think background microwave radiation originated from ? Why do scientists use radio telescopes to scan for extraterrestrial life instead of light telescopes ? Do you think that a) intelligent life exists elsewhere and b) will we ever know about this life form considering how vast our own galaxy is ? Radiation from deep space 10 18 Frequency (Hz) 10 7 10 18 Frequency (Hz) 10 7 Light microwave UHF VHF long wave Light microwave UHF VHF long wave Key concepts

23. P1.10 Plenary Lesson summary: SETI stars evidence life Friday 21 October 2011 SETI the ‘search for extra terrestrial life’ now has over 100,000 people worldwide linked via the worldwide web that allow their computers to be used by SETI to analyse huge amounts of data generated in the search for extra-terrestrial life. So far no evidence has shown its existence. Although planets like our own are common does intelligent life exits on one of them and will we ever know ? How Science Works: Research into how Earth and space bound telescopes like the ‘Hubble telescope’ has helped us to understand what the Universe is all about ? Preparing for the next lesson: Scientists have detected planets around some _____. These are called exoplanets. _____ may exist on other planets in the Universe, but there is so far no real scientific ________ for this. The ____ project continues to search for life elsewhere in the Universe. Decide whether the following statements are true or false : False True 3: The brighter a star the further it is away from us ? False True 2: One light year is the distance light travels in ten years ? False True 1: Alpha Centauri is the closest star outside our own galaxy ?

25. P1.11 The Great Debate of 1920 Extension questions: 1: Why was the discovery of other galaxies important scientifically ? 2: Does the existence of millions of other galaxies make life elsewhere in the Universe more or less likely ? 3: Some galaxies are so far away from us that the light that from these galaxies has taken many billions of years to reach Earth explain why these galaxies may no longer exist today ? 4: Why are telescopes used to observe distant galaxies and stars set up high on mountains and what is the difference between a nebula and a galaxy ? Know this: a: Know that the Milky Way is one of many millions of galaxies found in the Universe b: Know that all Galaxies contain thousands of millions of stars. Friday 21 October 2011 Introduction: Early in the twentieth century, the existence of other galaxies like our own Milky Way was contested by two scientists called Shapley and Curtis. Shapley claimed nebulae which seemed to be more than 100,000 lights years away were part of the Milky Way. Curtis argued that nebulae were outside our own Galaxy. Years later the scientist Edwin Hubble used a new telescope to find out how far the stars located in the Andromeda nebulae were away from Earth. His evidence showed that they were over million light years away, no part of the Milky way but in the Andromeda galaxy.

27. P1.11 b Look at the photograph and information and answer all the questions: Radio telescopes like those pictured opposite left constantly scan deep space for electromagnetic radio coming form distant stars and far away galaxies. SETI (search for extraterrestrial intelligence) has been funded to look for sign of intelligent life over the last 40 years. So far they have been unsuccessful ! Do you think we will find evidence of extraterrestrial life somewhere in our own galaxy and do you think we should continue to fund the work done by SETI ? Explain the difference between a light and radio telescope ? If we did receive some sort of message would we know where it came from and how long it took to reach us ? How radio telescopes work Key concepts

28. P1.11 Plenary Lesson summary: nebulae stars radiation distance Friday 21 October 2011 How Science Works: Research into how the Universe began and how our idea of how the Universe was created over the last 2000 years from scientists and philosophers including Ptolemy to Hawkins. Preparing for the next lesson: The ________ that distant stars and galaxies produce gives us information about the ________ to stars, and about how they are changing. With the naked eye you can see cloudy patches called ________. Nebulae are groups of millions of _____ called galaxies. Radio telescopes are mainly used to detect the radio waves (UHT VHT and long wave) coming from distant stars and galaxies and even planets home to intelligent life forms. Even if we do receive a signal form a life form, our answer may take hundreds even thousands of years to reach the sender due to the vast size of the Universe. Decide whether the following statements are true or false : False True 3: The Sun and the Solar System were formed 10,000 millions years ago ? False True 2: Hubble was involved in the Great Debate of 1920 ? False True 1: Light pollution is caused by stars ?

30. P1.12 How did the Universe begin? Extension questions: 1: List four observations that support the Big Bang theory ? 2: Explain how the red shift for every galaxies support the big bang theory ? 3: In your opinion, giving your learning, is the Big Bang theory credible ? 4: Explain Hubble’s law ? 5: Explain why the Catholic church is now begin to support the big band event as the moment God created the Universe ? Know this: a: Know that the Universe began with a Big Bang and since then it has been expanding. b: Know that the big band theory was first popularised by the physicist Stephen Hawkins. Friday 21 October 2011 Introduction: The Universe is everything. We are part of the Universe. The Universe is made up of millions of galaxies. All of these galaxies are moving away from us, because space and the Universe continues to expand. Hubble discovered that galaxies that are further away from us move faster than those that are closer to us, supporting the hypothesis that the Universe began with a big bang event. More recently, all observable galaxies has been shown to have a ‘red shift’, meaning that they are always moving away from us. These images further proves that the Universe and its galaxies are in constant expansion. (If the galaxies has a blue shift they would be in contraction or moving towards us.)

31. Key concepts P1.12 a Look at the photograph and information and answer all the questions: Why did Ptolemy and his peers in 140 AD think that the Earth was at the centre of the Universe ? Hubble's observation that the Milky Way was just one of many millions of galaxies was an important discovery…explain why ? Humans, for thousands of years have asked questions about their own history, the history of the solar system and Universe. Early philosophers and modern scientists have given us different answers to the one single question: How and when did the Universe begin ? Over the last two thousand years, many different theories have been offered by scientists to explain what events began, that led to the formation of the Universe and all the galaxies that we observe today . Ptolemy: Proposes in 140 AD that the Earth is a sphere and is at the very centre of the Universe. Copernicus: Proposes in 1600 AD that the Sun is the very centre of the Universe, with the Earth orbiting it. Hubble: Proposes that our galaxy, the Milky Way is just one of billions of similar Galaxies. Hawkins: Popularised that the Universe started with a big bang around 14 billion years ago and is still in constant expansion.

32. Key concepts P1.12 b Look at the photograph and information and answer all the questions: If all observable planets acquired a blue shift instead of a red shift what would this mean would be happening ? Explain why scientists cannot yet answer the question ‘will the Universe contract from its current size ? Since the ‘big bang’ the Universe continues to expand, but what other evidence do we have to support the big bang theory proposed by Stephen Hawking. If we observe the many thousands of visible galaxies using the Hubble telescope, they all have a red shift meaning that they are always moving away from us. These images proves that the Universe and its galaxies are in constant expansion. (If the galaxies has a blue shift they would be in contraction or moving towards us) Big bang the expanding Universe Expansion Contraction Red shift Blue shift

33. Key concepts P1.12 c Look at the photograph and information and answer all the questions: Some scientists claim that there are wormholes to other parallel Universe although this theories cannot be proved. Do you think we should except such a theory ? Why is it important that scientists shave their work independently checked and peer reviewed ? Stephen Hawkins proposed that around 14 billion years ago, all the matter of the Universe occupied a small volume and time was non existent. A massive explosion or ‘big bang’ sent matter in all directions, at temperatures of millions of degrees Celsius. Within a millisecond, matter was spread across many light years creating the Universe. Time had also started. Within hundredths of a second, matter had spread thousands of light years across. Over the next 13.7 billion years 100,000,000,000 galaxies have formed, each containing many billions of stars . time 13.7 billion years ago big bang

34. P1.12 Plenary Lesson summary: attract expand evidence crunch Friday 21 October 2011 ‘ Big Bang theory’ Stephen Hawkins proposes that the Universe started with a big bang and is in constant expansion. The age of the Universe is believed to be around 12 to 15 billions years old. Our own Sun is estimated to be around 4.5 billion years old. The Universe continues to expand from a central point. Whether this expansion will continue is still unanswered. How Science Works: Revision for end of module test. Preparing for the next lesson: We do not know what will happen to the Universe; scientists disagree about how to interpret _________ about its final fate. Maybe the Universe will continue to ________. Or perhaps the force of gravity will ________ galaxies towards each other again and the Universe will end with a ‘big _______’. Decide whether the following statements are true or false : False True 3: A scientific paper is reviewed once it has been published ? False True 2: The Universe is younger than the Sun ? False True 1: The ultimate fate of the Universe is easy to predict ?