Protons for Breakfast Week 1: Electricity

Protons for Breakfast Week 1: Electricity
November 2011

In the event of an alarm sounding…

Toilets…

Parents and children… Parents: You are responsible for your children’s behaviour.

The plan for the evening…
8:59 p.m. to 9:00 p.m. Feedback 8:30 p.m. to 8:59 p.m. More talk 8:00 p.m. to 8:29 p.m. Walkabout Talk 7:00 p.m. to 7:59 p.m. Parents: You are responsible for your children’s behaviour.

Mateusz Szymanski Neelaksh Sadhoo
Who is helping? Andrew Hanson Andy Knott Arzu Arinc Averil Horton Bufa Zhang Clare Lee Clare Matthews David Clay Deborah Lea Edward Brightman Elena Amico di Meane Emma Woolliams Gareth Hinds Gianluca Memoli Jacquie Elkin James Claverley James Miall Jane Burston Jeff Flowers Jenny Wilkinson Jian Wang Joanna Lee John Gallop John Makepeace John Mountford Jonathan Pearce Jordan Tompkins Joseph Thom Laurie Winkless Lindsay Chapman Lloyd England Louise Brown Maria Lodeiro Mateusz Szymanski Neelaksh Sadhoo Paul Carroll Peter Benson Peter EDMEAD Peter Quested Peter Woolliams Pippa Goldenberg Rainer Winkler Ralf Mouthaan Robert Goddard Ruth Montgomery Sharmila Hanson Stephanie Bell Sue Gibbons Tim Burnett Andrew Hanson Andy Knott Arzu Arinc Averil Horton Bufa Zhang Clare Lee Clare Matthews David Clay Deborah Lea Edward Brightman Elena Amico di Meane Emma Woolliams Gareth Hinds Gianluca Memoli Jacquie Elkin James Claverley James Miall Jane Burston Jeff Flowers Jenny Wilkinson Jian Wang Joanna Lee John Gallop John Makepeace John Mountford Jonathan Pearce Jordan Tompkins Joseph Thom Laurie Winkless Lindsay Chapman Lloyd England Louise Brown Maria Lodeiro Mateusz Szymanski Neelaksh Sadhoo Paul Carroll Peter Benson Peter EDMEAD Peter Quested Peter Woolliams Pippa Goldenberg Rainer Winkler Ralf Mouthaan Robert Goddard Ruth Montgomery Stephanie Bell Sue Gibbons Tim Burnett

Thanks NPL: The National Physical Laboratory Serco:
Manage NPL on behalf of the BIS Amey: Who set out the rooms

Michael de Podesta Age 51: Lecturer in Physics at University of London for 13 years At NPL for 11 years. Just built the most accurate thermometer on Earth. Surface Temperature Initiative Married with two sons (13 & 15) Keen on Water Rockets MBE! Not much of a CV, but its all I’ve got! I should really talk about some of the projects I’ve worked on, but there isn’t time.

Science is humanity’s greatest achievement
Why am I here? I am here because I believe … Science is humanity’s greatest achievement What is the problem? Well its too big to summarise on a single slide. It involves ideas such as The ownership of scientific ideas Are scientists like ‘high priests’ guarding the ‘holy of holies’ Can we trust scientists? Can we trust anyone else? And compounding all these questions about science is an overwhelming ignorance about science, and not just modern science, science which is which is 100 years old! Personally I feel resolution of this conflict lies at the interface of the personal with the technical. And the problem is not just ignorance. We are all ignorant of lots of things, but in general ignorance of, say, Shakespeare’s plays or of historical events does not make us feel powerless to choose what to do in the world.

Why are you here? I want to learn more about science and how it affects me To refresh, enhance and improve my knowledge of Science for teaching at Primary level. Also to help me make teaching Science fun! My teacher told me that I would love it. I am also interested by science. I know very little about science, and would like to learn some more. Personal Interest in the topics of Weeks 4, 5 & 6 in particular – but also bringing my daughters along who are interested in Science Like my wife who has already submitted an application I am "simply curious about science" What is the problem? Well its too big to summarise on a single slide. It involves ideas such as The ownership of scientific ideas Are scientists like ‘high priests’ guarding the ‘holy of holies’ Can we trust scientists? Can we trust anyone else? And compounding all these questions about science is an overwhelming ignorance about science, and not just modern science, science which is which is 100 years old! Personally I feel resolution of this conflict lies at the interface of the personal with the technical. And the problem is not just ignorance. We are all ignorant of lots of things, but in general ignorance of, say, Shakespeare’s plays or of historical events does not make us feel powerless to choose what to do in the world. Because I hated science at school, but now, really interested, I lack the basics!

…there is a problem about how we, as citizens, relate to science…
What is the problem? Well its too big to summarise on a single slide. It involves ideas such as The ownership of scientific ideas Are scientists like ‘high priests’ guarding the ‘holy of holies’ Can we trust scientists? Can we trust anyone else? And compounding all these questions about science is an overwhelming ignorance about science, and not just modern science, science which is which is 100 years old! Personally I feel resolution of this conflict lies at the interface of the personal with the technical. And the problem is not just ignorance. We are all ignorant of lots of things, but in general ignorance of, say, Shakespeare’s plays or of historical events does not make us feel powerless to choose what to do in the world.

The image of science:1 Mad Muppets top cult science poll
Dr Honeydew is known the world over for his disastrous research at Muppet Labs, "where the future is being made today". Scientists are quite nice when they are incompetent. Think of adjective for the word ‘scientist’ Be honest. Did the word ‘mad’ pop into your head? Why do we have such an immediately cynical (rather than sceptical) image of a scientists His experiments invariably go awry, with poor old Beaker usually being blown to bits or electrocuted. BBC 6/9/2004

The image of science:2 Science Gone Wrong
Scientists are quite nice when they are incompetent. Think of adjective for the word ‘scientist’ Be honest. Did the word ‘mad’ pop into your head? Why do we have such an immediately cynical (rather than sceptical) image of a scientists The final touch… What! BANG! Alex Noble (Age 9)

The image of science:3 An un-scientific experiment
Scientist ……… Scientist Scientists are quite nice when they are incompetent. Think of adjective for the word ‘scientist’ Be honest. Did the word ‘mad’ pop into your head? Why do we have such an immediately cynical (rather than sceptical) image of a scientists

In contrast… A room full of people who want to learn about science
Helped by volunteers In a world where ignorance makes us powerless Missing Eastenders and Emmerdale And yet here we all are… Science has an overwhelming presence in our lives from entertainment, through health, through our work, and as a focus for curiosity and imagination.

Tonight’s talk The scale and size of the Universe
Its very big, but full of very small things The electric force It dominates every physical phenomenon on our scale. How the force works Electric particles Electric field Light Waves in the Electric field This is the plan

The scale and size of the Universe
Tonight’s talk The scale and size of the Universe or ‘How not to be boggled!’ This is the plan

The imperceptible and the vast
As human beings we can judge: temperatures close to ‘normal’ weights greater than a gram up to around 1000 kilograms distances greater than a millimetre or less than a few kilometres. times greater than a second or less than a fraction of a lifetime. Roughly speaking, we can extend our perception by a factor 1000 away from the scale with which we are familiar. Beyond this we are just lost. The effect is not only true of distance (though that’s what we concentrate on). Its true of time. We can’t appreciate things happen in a time much faster than 1 second Time scales longer than 1 year are hard to appreciate Time scales longer than a lifetime are especially hard to appreciate No known civilisation has last much more than 1000 years The world is at least 1 million times older than 1000 years

As human beings we cannot judge: temperatures more a few degrees away from ‘normal’ Such temperatures just feel ‘very hot’ or ‘very cold’ weights beyond a few tonnes or less than a gram Such weights seem either stupendously heavy or negligible distances less than a millimetre or greater than a few kilometres. Such distances are too tiny or too far to perceive directly times less than a second or more than a fraction of a lifetime. Such times are too small or too long for us to appreciate Roughly speaking, we can extend our perception by a factor 1000 away from the scale with which we are familiar. Beyond this we are just lost. The effect is not only true of distance (though that’s what we concentrate on). Its true of time. We can’t appreciate things happen in a time much faster than 1 second Time scales longer than 1 year are hard to appreciate Time scales longer than a lifetime are especially hard to appreciate No known civilisation has last much more than 1000 years The world is at least 1 million times older than 1000 years

Measuring instruments extend our senses Telescopes & Microscopes, Weighing machines, Devices sensitive to electricity & light, Clocks NPL: Enables people to trust measurements Measurement: Quantitative comparison Measuring instruments extend our senses beyond the familiar Telescopes & Microscopes Weighing machines Devices sensitive to electricity & light Clocks But we then have to trust these measurements! To ‘report’ the nature of the micro and the ‘macro’ world To ‘report’ on temperatures we cannot sense. To ‘report’ weights beyond a few tonnes or less than a gramme To ‘report’ on events occurring too rapidly or slowly for us to appreciate The perceptible and the imperceptible A feather falls onto the shoulder of a man as he gets into a train. Does the train use up more fuel to carry him than if he left the feather at home? The tides are affected by the motion of the Moon around the Earth. Are the tides affected by the motion of Jupiter? When you jump, does the Earth move? Does driving your car to work (or choosing not to) affect the CO2 concentration in the atmosphere? Does a fan really cool a room, or heat it up?

Science helps us extend our senses But we can still feel boggled!
Quantities and qualities that extend beyond our ability to perceive them seem: imperceptible or vast ? ? The perceptible and the imperceptible A feather falls onto the shoulder of a man as he gets into a train. Does the train use up more fuel to carry him than if he left the feather at home? The tides are affected by the motion of the Moon around the Earth. Are the tides affected by the motion of Jupiter? When you jump, does the Earth move? Does driving your car to work (or choosing not to) affect the CO2 concentration in the atmosphere? Does a fan really cool a room, or heat it up? Science helps us extend our senses But we can still feel boggled!

The Planet Earth 12,800 km 10 km Diameter: Deepest hole: Atmosphere:
This is a picture of the Earth Taken from apollo 17. The key point is that this scale of viewing is beyond the direct experience of all but a handful of humanity. But having once seen the image, its hard to live life in the same way. The connections between the Earth, its place in space, and common home of humanity and the flora and fauna of the planet become obvious in a way they are not from the ground. The atmosphere is not a well defined layer: The density of the air falls to around 37% of its value at the ground at a height 8 km The density of the air falls to around 14% of its value at the ground at a height 16 km The density of the air falls to around 5% of its value at the ground at a height 24 km The temperature of the air falls by between 6 C and 9 C for every km rise above the Earth’s Surface Mount Everest is about 10 km high The deepest trench in the ocean is about 11 km deep The Earth itself is very big: The deepest hole ever drilled is around 11 km deep The temperature rises as one goes deeper in the Earth by around 30 C every km Photo Credit: NASA

The Moon Diameter Earth: 12,800 km Moon: 3476 km Photo Credit: NASA
The Moon has approximately 1/4 Earth's diameter, 1/50 Earth's volume, and 1/80 Earth's mass. Earth is very dense overall (it is the densest planet in the Solar System), but the Moon is light for its size. The difference is partly because Earth has a large core of iron and other heavy metallic elements, while the Moon has only a small core, if it has a core at all. The Moon's surface gravity is 1/6 of Earth's, and escape velocity from the surface is about 1/5 of Earth's. The Moon's surface is covered with rock and grit that are mostly dark-gray minerals, so it reflects light poorly compared to Earth, which always has highly-reflective clouds. The Moon reflects visible light about 1/3 as well as Earth, and because of its much smaller size, has a visual brightness less than 1/40 that of Earth, when both are fully illuminated and seen from the same distance -- a difference of four stellar magnitudes. EarthMoon Mean diameter12,742 km 3,476 km Volume x 1012 km3 2.199 x 1010 km3 Mass x 1024 kg x 1022 kg Mean density Surface gravity9.78 m/s m/s2 Escape velocity11.2 km/s 2.38 km/s Visual albedo Visual magnitude At right: Earth and Moon to the scale of 1 pixel = 50 km. The Moon's surface area is a bit greater than Africa's This is a picture of the sun taken through a filter to allow the surface to be seen Also shown is a picture shows very approximately the relative sizes of the Earth and the Sun. We are familiar with the idea that Sun is very hot, but its vastness is pretty humbling. Photo Credit: NASA

The Sun Earth Diameter: 1,390,800 km Photo Credit: NASA
Let me boggle you some more with the vastness of the universe. This is a picture of the sun taken through a filter to allow the surface to be seen Also shown is a picture shows very approximately the relative sizes of the Earth and the Sun. We are familiar with the idea that Sun is very hot, but its vastness is pretty humbling. Photo Credit: NASA Earth

Photo Credit: Powers of 10
Powers of Ten I hope that you are now a little unsettled and ready to go on a 9 minute journey to see how the world looks at different levels of ‘fantasy magnification’ Powers of ten video Photo Credit: Powers of 10

Can you see the problem with very small and very large numbers?
Powers of Ten (1) 1 metre m m m Very Very Small Very Very Large 0.001 m m m 1000 m Scientists use ‘scientific notation’ to cope with the vastness and tiny-ness of the numbers they encounter. Can you see the problem with very small and very large numbers?

Powers of Ten (2) 100 1 Very Very Small Very Very Large 10-15 10-9
10-18 10-12 10-6 106 1012 1018 1024 1030 1036 1021 1027 1033 10-3 0.001 1000 103 109 1015 Scientists use ‘scientific notation’ to cope with the vastness and tininess of the numbers they encounter.

Powers of Ten (3) 1 metre 1012 1000000000000 m 0.000000000001 m 10-15
10-9 10-18 10-12 10-6 106 1012 1018 1024 1030 1036 Very Very Small Very Very Large 10-3 103 109 1015 1021 1027 1033 Scientists use ‘scientific notation’ to cope with the vastness and tininess of the numbers they encounter.

Powers of Ten Length Scale in metres
Diameter of a hair Diameter of the Earth Distance to the Sun Current estimate of the size of the universe Viruses Microbes 100 Human Relationships Quarks 10-18 10-12 10-6 106 1012 1018 1024 1030 1036 ? Nuclei of atoms Very Very Small Very Very Large Atoms & molecules Nanotechnology Tallest Mountain Light Year Nearest Star 10-15 10-9 10-3 103 109 1015 1021 1027 1033 Current estimate of the size of the Universe is 78 billion light years, This is interesting because its only supposed to be around 13 billion years old! The discrepancy is resolved by a period of so-called ‘inflation’ in the first fraction of a second of the early universe. Picture Credit: COBE Website Stars ithin 12 light years of Earth Micrograph of a nanowire curled into a loop in front of a strand of human hair. The nanowires can be as slender as 50 nanometers in width, about one-thousandth the width of a hair. Credit: Limin Tong/Harvard University Smallpox image Virus Image Pentium Chip Quark Image Mountain

Powers of Ten Length Scale in metres
? What goes on here? String Theory M-Branes ???????? 103 106 109 1012 1015 10-3 10-6 1018 1024 1030 1036 1021 1027 1033 10-15 10-9 10-18 10-12 100 Human Relationships Distance to the Sun Atoms & molecules Nuclei of atoms Current estimate of the size of the universe Nearest Star Light Year Tallest Mountain Nanotechnology Diameter of the Earth Diameter of a hair Microbes Viruses Quarks Powers of Ten Length Scale in metres Large Hadron Collider 10-21 10-24 10-33 10-27 10-36 10-30 Large Hadron Collider Current estimate of the size of the Universe is 78 billion light years, This is interesting because its only supposed to be around 13 billion years old! The discrepancy is resolved by a period of so-called ‘inflation’ in the first fraction of a second of the early universe. Picture Credit: COBE Website Stars ithin 12 light years of Earth Micrograph of a nanowire curled into a loop in front of a strand of human hair. The nanowires can be as slender as 50 nanometers in width, about one-thousandth the width of a hair. Credit: Limin Tong/Harvard University Smallpox image Virus Image Pentium Chip Quark Image Mountain

Powers of Ten Global Warming
Distance to the Sun Tallest Mountain Diameter of the Earth Atoms & molecules Microbes Human Relationships 10-18 10-12 10-6 100 106 1012 1018 1024 1030 1036 Very Very Small Very Very Large 10-15 10-9 10-3 103 109 1015 1021 1027 1033 Current estimate of the size of the Universe is 78 billion light years, This is interesting because its only supposed to be around 13 billion years old! The discrepancy is resolved by a period of so-called ‘inflation’ in the first fraction of a second of the early universe. Picture Credit: COBE Website Stars ithin 12 light years of Earth Micrograph of a nanowire curled into a loop in front of a strand of human hair. The nanowires can be as slender as 50 nanometers in width, about one-thousandth the width of a hair. Credit: Limin Tong/Harvard University Smallpox image Virus Image Pentium Chip Quark Image Mountain The phenomenon of global warming involves physical processes with length scales spanning 20 powers of 10!

Powers of Ten Nuclear Power
Distance to the Sun Diameter of the Earth Atoms & molecules Microbes Human Relationships 10-18 10-12 10-6 100 106 1012 1018 1024 1030 1036 Very Very Small Nuclei of atoms Very Very Large 10-15 10-9 10-3 103 109 1015 1021 1027 1033 Current estimate of the size of the Universe is 78 billion light years, This is interesting because its only supposed to be around 13 billion years old! The discrepancy is resolved by a period of so-called ‘inflation’ in the first fraction of a second of the early universe. Picture Credit: COBE Website Stars ithin 12 light years of Earth Micrograph of a nanowire curled into a loop in front of a strand of human hair. The nanowires can be as slender as 50 nanometers in width, about one-thousandth the width of a hair. Credit: Limin Tong/Harvard University Smallpox image Virus Image Pentium Chip Quark Image Mountain The issues surrounding nuclear power involve physical processes with length scales spanning 25 powers of 10! Tallest Mountain

Powers of Ten (time) Time scale in seconds
Earth moves once around the Sun Estimated time since the big bang Light wave wiggles once Time for a molecule to jiggle once 10-18 10-12 10-6 100 106 1012 1018 1024 Very Very short Sound travels 1 metre Fastest response of human eye A human lifetime Lifetime of a Civilisation End of last ice age Age of the Earth Very Very Long 10-15 10-9 10-3 103 109 1015 1021 On this scale it doesn’t seem long since the whole thing began! But what’s interesting is the lifetime of ‘civilisations’: not very long is it! Eye Pyramid Mammoth Old Earth Earth Orbit Big Bang Clock Light Wave Sound Wave

? The Universe Its very big, but full of very small things ?
The perceptible and the imperceptible A feather falls onto the shoulder of a man as he gets into a train. Does the train use up more fuel to carry him than if he left the feather at home? The tides are affected by the motion of the Moon around the Earth. Are the tides affected by the motion of Jupiter? When you jump, does the Earth move? Does driving your car to work (or choosing not to) affect the CO2 concentration in the atmosphere? Does a fan really cool a room, or heat it up?

Electricity Electricity This is the plan

How it all fits together…
Electricity Atoms Heat And a pictorial summary for those who appreciate things that way. Electromagnetic waves

Eeeee - lec- tric-ity Electricity
This is the plan

Electricity Some experiments… This is the plan

Lets take a look at some odd phenomena…
A balloon and a piece of paper How can a balloon pick up a piece of paper? You might think this is a party trick, but it is not. Because there is nothing very special about these objects. So how does this happen. Some of you might think ‘well that’s just static electricity’ (and you’re right except for the word ‘just’) because it begs one big question… How did we get electricity out of a balloon? Or did the electricity come out of my shirt? The point is that everything – and I mean EVERYTHING - Everything is FULL of electricity so that you can get electricity out of anything! And in the break you will have a chance to do some experiments and see that absolutely anything can be induced be attracted to a balloon. But to understand how that attraction works you need to understand something very profound about the world: what it is made of…. Electron is the Greek word for ‘amber’

Lets take a look at some odd phenomena…
If I balance my glasses carefully… How can a balloon pick up a piece of paper? You might think this is a party trick, but it is not. Because there is nothing very special about these objects. So how does this happen. Some of you might think ‘well that’s just static electricity’ (and you’re right except for the word ‘just’) because it begs one big question… How did we get electricity out of a balloon? Or did the electricity come out of my shirt? The point is that everything – and I mean EVERYTHING - Everything is FULL of electricity so that you can get electricity out of anything! And in the break you will have a chance to do some experiments and see that absolutely anything can be induced be attracted to a balloon. But to understand how that attraction works you need to understand something very profound about the world: what it is made of…. Electron is the Greek word for ‘amber’

Even a sausage… Sausages… How can a balloon pick up a piece of paper?
You might think this is a party trick, but it is not. Because there is nothing very special about these objects. So how does this happen. Some of you might think ‘well that’s just static electricity’ (and you’re right except for the word ‘just’) because it begs one big question… How did we get electricity out of a balloon? Or did the electricity come out of my shirt? The point is that everything – and I mean EVERYTHING - Everything is FULL of electricity so that you can get electricity out of anything! And in the break you will have a chance to do some experiments and see that absolutely anything can be induced be attracted to a balloon. But to understand how that attraction works you need to understand something very profound about the world: what it is made of…. Electron is the Greek word for ‘amber’

…its everything… The balloon affects anything and everything nearby
To understand this, we need to understand what matter is made of, and how this ‘influence’ is communicated across ‘space’ My wife told me not to do this. So be careful you don’t break your glasses

A simple scientific instrument: The gold leaf electroscope
Scientists can develop instruments to measure the relative strengths of the ‘electric influence’ Based on the same effect we saw with bits of paper (A) Large gold leaf electroscope Made by Watkins & Hill English, 2nd quarter 19th century, signed in script on the brass base, "Watkins & Hill, Charing Cross, London." The lacquered brass base is 6 3/8" diameter, with a 4 3/4" diameter x 9" tall glass bell jar cemented to the base. The bell jar has an insulating conductor which feeds through the top to hold the slips of gold leaf. (B) Small gold leaf electroscope English, 2nd quarter 19th century, unsigned, but probably also by Watkins & Hill. The brass base is 3 1/2" diameter, with a 3" diameter x 4 1/2" tall glass bell jar cemented to the base. The bell jar has an insulating conductor which feeds through the top to hold the slips of gold leaf.

The Van de Graaff Generator
The American physicist Robert Jamison Van de Graaff was born in Alabama in After having received a masters degree in mechanical engineer in Alabama, he moved to Paris where he attended the courses of Marie Curie at La Sorbonne University. In 1925 he went to Oxford Universitv, where, three years later he received a D.Phil. in physics. In 1929 Van de Graaff joined Princeton University as a National Research Fellow and at the end of the same vear he built the first model of his generator (80 kVolt). Soon the apparatus was improved and, in November 1931, he demonstrated for the first time a new, inexpensive and much more powerful machine (about 1-1,5 MVolt) at the inaugural dinner of the American Institute of Physics. Van de Graaff joined then the Massachusetts Technological Institute (MIT) as a research associate and in 1931 he began to construct a large double generator in an unused dirigible shed at Round Hill (South Dartmouth, Mass.) Scientists can develop machines to automate and amplify the ‘rubbing’ process with the balloon Photo Credits: Katherine Robinson and MIT

The Van de Graaff Generator
It is not important to understand how a Van de Graaff generator works Actually, its not important at all! All you need to appreciate for his course is that the electricity comes out of ordinary matter! If you want to read about it try the how stuff works web site PictureCredits:

It is not important to understand how a Van de Graaff generator works
The Van de Graaff Generator It is not important to understand how a Van de Graaff generator works

Sorry: I cannot explain how a Wimshurst Machine works!
The Wimshurst Machine Sorry: I cannot explain how a Wimshurst Machine works! Actually, its not important at all! All you need to appreciate for his course is that the electricity comes out of ordinary matter! Sparks occur when electric field strength exceeds V per cemtimeter. A 3.3 cm spark (1.3 inches) = V Photo Credits: Wikipedia and

Electrostatic Generators
People have been doing this for a long time… Not really relevant but I like these pictures Photo Credits:

Electricity is present inside ALL matter
Conclusion… Electricity is present inside ALL matter Its ‘influence’ can be communicated across ‘empty’ space This is the plan

How do we describe the world?
Stuff matter Not Stuff the gaps in between matter fields This is an oversimplification. However it is important to get in mind the idea that fields really do exist. If you took all the matter i.e the atoms out of box it would not be empty. It would still contain the fields. (also I should say that ‘stuff’ and ‘not stuff’ are not technical scientific terms.)

This is an oversimplification. However it is important to get in mind the idea that fields really do exist. If you took all the matter I.e the atoms out of box it would not be empty. It would still contain the fields. Each field is linked to a particular property of matter. Atom comes from the Greek ‘A tom’ ‘Tom’ means a slice (as in ‘tomography’ which ‘slices’ through things) ‘A’ means ‘ not’ So an A-tom should be not-sliceable. In fact atoms are ‘s;iceable’ The Strong nuclear ‘colour charge (three different types)’ Quarks interact with other quarks by means of a so-called ‘colour’ field Sticks protons to neutrons in the nucleus of the atom Mass Masses interact with other masses by means of a gravitational field Sticks us to the planet Gravitational forces are always attractive Electron comes from Elektron, the greek word for ‘Amber’

Two different kinds of physical entity Stuff (Particles) Atoms Electrons Neutrons Protons Very small Not Stuff (Fields) Fields Gravitational Electroweak Strong Extend throughout space This is an oversimplification. However it is important to get in mind the idea that fields really do exist. If you took all the matter I.e the atoms out of box it would not be empty. It would still contain the fields. Each field is linked to a particular property of matter. Atom comes from the Greek ‘A tom’ ‘Tom’ means a slice (as in ‘tomography’ which ‘slices’ through things) ‘A’ means ‘ not’ So an A-tom should be not-sliceable. In fact atoms are ‘s;iceable’ The Strong nuclear ‘colour charge (three different types)’ Quarks interact with other quarks by means of a so-called ‘colour’ field Sticks protons to neutrons in the nucleus of the atom Mass Masses interact with other masses by means of a gravitational field Sticks us to the planet Gravitational forces are always attractive Electron comes from Elektron, the greek word for ‘Amber’ We need to know about both particles and fields

How do charged particles interact?
It’s a three-step process… Particle with electric charge Particle with electric charge Interact by means of an electric field We will look at this 3 step process again next week …but the steps happen very quickly

This is an oversimplification. However it is important to get in mind the idea that fields really do exist. If you took all the matter I.e the atoms out of box it would not be empty. It would still contain the fields. Each field is linked to a particular property of matter. Atom comes from the Greek ‘A tom’ ‘Tom’ means a slice (as in ‘tomography’ which ‘slices’ through things) ‘A’ means ‘ not’ So an A-tom should be not-sliceable. In fact atoms are ‘s;iceable’ The Strong nuclear ‘colour charge (three different types)’ Quarks interact with other quarks by means of a so-called ‘colour’ field Sticks protons to neutrons in the nucleus of the atom Mass Masses interact with other masses by means of a gravitational field Sticks us to the planet Gravitational forces are always attractive Electron comes from Elektron, the greek word for ‘Amber’

Tonight’s talk…(3) The scale and size of the Universe
Its very big, but full of very small things The electric force It affects everything How the force works Electric particles Electric field Light Waves in the Electric field This is the plan

The electrical nature of matter
Electric charge is a fundamental property of electrons and protons. Two types of charge (+ and -) If particles have the same sign of electric charge they repel If particles have different signs of electric charge they attract The forces (attractive or repulsive) get weaker as the particles get further apart.

Protons, neutrons and electrons normally exist inside atoms

Atoms 0.001 mm 0.01 mm 0.1 mm 1 mm Atoms are small
Think of a millimetre Atoms are roughly 10,000 times smaller than this…

Atoms There are VAST numbers of atoms in everything. In just a handful of anything there are about the same number of atoms as there are grains of sand on all the beaches and deserts on Earth combined It you dropped a cup of water in the ocean and waited for it to mix with the whole ocean (a long time) then if you dipped your cup anywhere in the ocean, you would be likely to capture some of the atoms you originally poured in. Really?: From the Web I see the average depth of the oceans is 3500 m and they cover around 70% of the Earth's surface. Their volume is therefore amounts to 1.3 x1018 cubic metres which is 1.3 x 1021 litres. If a cup contains 300 ml, then when poured into the ocean it will be diluted 1 part cup-water to 4.2 x 1021 parts ocean water. Now 18 ml of water contains 6 x molecules so 300 ml contains molecules. After dilution, each cup-size part of ocean water will contain 2380 molecules of water. Ish m = radius of Earth in metres (m) 1.2868E+14 = Surface area of Earth 0.3 = Fractional Surface area of Land 1m Depth Layer 3.86E+13 = Volume (m3)of surface layer 1 m deep 1 mm^3 = Volume of a single grain (mm^3) = Volume of a single grain (m^3) 3.86E+22 = Number of particles in layer Typica ldensity of anything = 5000kg/m^3 Typical Molecular Weight 50 Typical molar volume m^3 Typical molar volume 0.01 litres Typical molar volume 10 cc So 1 cc is about 0.1 mole 1cc is about 6.2e22 particles Photo Credit: ID =

Atoms Internal Structure

Interact by the short range ‘strong’ force – not electrical
How are atoms made? Electrical Repulsion proton Interact by the short range ‘strong’ force – not electrical Protons created about 1 second after the big bang

How are atoms made? Protons created about 1 second after the big bang

Atomic Structure Electrons Nucleus
‘orbit’ around the outside of an atom very light possess a property called electric charge Nucleus occupies the centre very tiny and very heavy protons have a property called electric charge neutrons have no electric charge Despite their miniscule size, we know about their internal structure from several experiments but importantly we can look at the light which emerges from atoms.

Atomic Structure Nuclei (+) attract electrons (-) until the atom as a whole is neutral The electrons repel each other They try to get as far away from each other as they can, a and as near to the nucleus as they can

Chemistry Atoms, Elements & Molecules

Atoms &… The Periodic Table
Atoms with up to about 82 protons can be stable. A material made up of a single type of atom is called an element C Carbon 6 Protons 6 Electrons The periodic table is a stunning achievement bringing order out of the bewildering diversity of material properties It has many different representations, but the one on the left is most common By ‘stable’ I mean not radioactive (see week 6 notes) Lyrics ==== There’s antimony, arsenic, aluminum, selenium, And hydrogen and oxygen and nitrogen and rhenium, And nickel, neodymium, neptunium, germanium, And iron, americium, ruthenium, uranium, Europium, zirconium, lutetium, vanadium, And lanthanum and osmium and astatine and radium, And gold and protactinium and indium and gallium, <gasp> And iodine and thorium and thulium and thallium. There’s yttrium, ytterbium, actinium, rubidium, And boron, gadolinium, niobium, iridium, And strontium and silicon and silver and samarium, And bismuth, bromine, lithium, beryllium, and barium. There’s holmium and helium and hafnium and erbium, And phosphorus and francium and fluorine and terbium, And manganese and mercury, molybdenum, magnesium, Dysprosium and scandium and cerium and cesium. And lead, praseodymium, and platinum, plutonium, Palladium, promethium, potassium, polonium, And tantalum, technetium, titanium, tellurium, <gasp> And cadmium and calcium and chromium and curium. There’s sulfur, californium, and fermium, berkelium, And also mendelevium, einsteinium, nobelium, And argon, krypton, neon, radon, xenon, zinc, and rhodium, And chlorine, carbon, cobalt, copper, tungsten, tin, and sodium. These are the only ones of which the news has come to ha’vard, And there may be many others, but they haven’t been discavard.

Atoms &… Molecules H N N2 H2 N H H H20 H
A molecule is a collection of atoms stuck together electrically. H N N2 H2 H N H H20 Pictures are from H

Atoms &… Ions A ion is an atom or molecule which has lost or gained an electron. Pictures are from

Solids

Atoms in solids Atoms can be imaged on a surface
Pb on Cu(111) On (111)-oriented Cu surfaces, it all starts with a surface alloy, i.e., some Cu atoms are replaced by Pb. It is quite tricky to get atomic resolution on the Cu surface and not disturb the structure too much, since one has to approach the STM tip to a rather close distance, where it interacts with the Pb atoms (those with a dark "halo"). The tip-sample interaction also causes movement of atoms at the monatomic step in the left part of the image and makes it appear frizzy. With increasing Pb deposition and gentle heating (to facilitate the exchange between Pb and Cu atoms in the surface), the surface alloy contains more and more Pb atoms up to a maximum density, where approx. 22 % of the Cu atoms are replaced by Pb. In the following STM image of this disordered surface alloy, only the Pb atoms are visible, not the Cu's. The Pb atoms are still surrounded by 6 (invisible) Cu neighbours each, but usually there are 2 or 3 Pb (and 4 or 3 Cu) next-nearest neighbours to a Pb atom. for explanation of how these images were made If you dropped a cup of water in the ocean and waited for it to mix with the whole ocean (a long time) then if you dipped your cup anywhere in the ocean, you would be likely to capture some of the atoms you originally poured in. Really?: From the Web I see the average depth of the oceans is 3500 m and they cover around 70% of the Earth's surface. Their volume is therefore amounts to 1.3 x1018 cubic metres which is 1.3 x 1021 litres. If a cup contains 300 ml, then when poured into the ocean it will be diluted 1 part cup-water to 4.2 x 1021 parts ocean water. Now 18 ml of water contains 6 x molecules so 300 ml contains molecules. After dilution, each cup-size part of ocean water will contain 2380 molecules of water. Ish Photo Credit: Patrick Josephs Franks: NPL

In ‘normal’ matter, there are equal quantities of positive and negative charge so that there is no attraction or repulsion of objects. Object 1 Object 2

Mechanical Properties

Atoms and mechanics Object 1 Object 2
Whenever two materials touch, the forces between them are the forces between the outer (valence) electrons All mechanical forces are actually electrical in nature Object 1 Object 2 I like to think that Valence electrons (the outer electrons) are frilly like a valence is the frilly bit around the outside of a bed.

Conductors and Insulators

Atoms in solids Solids are made up out of lots atoms very close together. If the electrons can’t move easily from atom to atom: The material is called an insulator If the electrons can move easily from atom to atom: The material is called a conductor But whether its an insulator or a solid its still ‘full’ of electrons (and so for that matter is a liquid or a gas!)

Magnetic Forces

Magnetism Electric & Magnetic
Magnetic forces arise when particles are moving with resepct to us and each other. The connection to electricity was first understood by Albert Einstein in his Theory of Relativity We call forces ‘magnetic’ when both particles are moving with respect to us. They are still electrical in origin. This was first explained by Albert Einstein in his Theory of Relativity

How the balloon affected the paper…

Odd phenomena… A balloon and a piece of paper
How can a balloon pick up a piece of paper? You might think this is a party trick, but it is not. Because there is nothing very special about these objects. So how does this happen. Some of you might think ‘well that’s just static electricity’ (and you’re right except for the word ‘just’) because it begs one big question… How did we get electricity out of a balloon? Or did the electricity come out of my shirt? The point is that everything – and I mean EVERYTHING - Everything is FULL of electricity so that you can get electricity out of anything! And in the break you will have a chance to do some experiments and see that absolutely anything can be induced be attracted to a balloon. But to understand how that attraction works you need to understand something very profound about the world: what it is made of…. Electron is the Greek word for ‘amber’

How is the electrical force transmitted from one charged particle to another?

How do charged particles interact?
It’s a three-step process… Particle with electric charge Particle with electric charge Interact by means of an electric field We will look at this 3 step process again next week …but the steps happen very quickly

The nature of interactions (1)
Analogy with water level and water waves Notice the red blob doesn’t start to move until a little while after the red thing has already started moving

Tonight’s talk…(4) Its very big, but full of very small things
The scale and size of the Universe Its very big, but full of very small things The electric force It affects everything. How the force works Electric particles Electric field Light Waves in the Electric field This is the plan

Summary Physics concepts span vast ranges of mass, length and time.
The universe has two kinds of objects in it: Matter and Fields All matter (on Earth) is made of atoms which interact electrically. In matter as we normally experience it, there are equal amounts of the two types of electric charge and their effects cancel If we add or remove some particles with electric charge from matter then we can see the electrical effects. I have added the qualification ‘On Earth’ because in fact most matter in the Universe as a whole is in stars, and exist in the form of a plasma (like in a flame) and here the atoms are broken apart to some extent.

Homework?

Homework Hertz Kilohertz Megahertz
Activity: Remember when you have your breakfast that you are eating protons and neutrons coated with tasty electrons. Research: What is the ‘frequency’ of your favourite radio station? Don’t just get the number (98.9, 198 etc.) get the units as well! They should be in Hertz Kilohertz Megahertz

One minute feedback On the back of your handouts!
Rip off the last sheet Please write down what is in on your mind RIGHT NOW! A question? OK A comment? OK A surprising thought in your mind? I’d love to hear it!

On-line Resources www.protonsforbreakfast.org
This PowerPoint ™ presentation. Handouts as a pdf file blog.protonsforbreakfast.org Links to other sites & resources Me going on about things

Goodnight See you next week! Don’t forget your pencils and badges!

Goodnight

Protons for Breakfast Week 1: Electricity

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