Post on 18-Jan-2016
Protons for Breakfast
Week 1: Electricity
November 2012
In the event of an alarm sounding…
Toilets…
Parents and children…
The plan for the evening…
7:00 p.m. to
7:59 p.m.
8:00 p.m.to
8:29 p.m.
Walkabout 8:59 p.m.to
9:00 p.m.
Feedback
Talk
8:30 p.m.to
8:59 p.m.
More talk
Who is helping? Andrew HansonAndy KnottAveril HortonBufa ZhangCat FitzpatrickChantal MustoeClaire GreenwellDavid ClayDeborah LeaEdward BrightmanEmma WoolliamsGianluca MemoliJacquie Elkin James ClaverleyJames MiallJane BurstonJane Scott
Paul GreenPeter BensonPeter EdmeadPeter Nisbet-JonesPeter QuestedPeter WoolliamsPippa GoldenbergRainer WinklerRalf MouthaanRobert GoddardRuth MontgomeryRuth PearceSharmila HansonStephanie BellSue Gibbons
Jeff FlowersJenny HullyJenny WilkinsonJohn GallopJohn MakepeaceJohn MountfordJonathan PearceJordan TompkinsJoseph ThomKate WilkinsonLaurie WinklessLindsay ChapmanLloyd EnglandLouise BrownMaria LodeiroMarta Doval MinarroPaul Carroll
Thanks
• NPL:
The National Physical Laboratory
• Serco:
Manage NPL on behalf of the BIS
• Amey:
Who set out the rooms
Michael de Podesta
Age 52:
• Lecturer in Physics at University of London for 13 years
• Understanding the Properties of Matter
• At NPL for 12 years.
• Most accurate thermometer ever made!
• International Surface Temperature Initiative
• Married with two sons(aged 14 & 16)
• Keen on Water Rockets
Member of the Most Excellent Order of the British Empire!
Why am I here?
I am here because I believe …
Science is humanity’s greatest achievement
Why are you here?
• Accompanying my daughter but also interested in how science is applied in everyday life.
• Science teacher has suggested it• Supporting my daughters who both love Science and keep
asking questions I can't answer!.• Fun• I have been home tutored since May and my science
teacher has been amazing and taught me so much. I am really interested in science and particularly the universe.
• My husband had a physics PhD and my youngest son has just graduated from Imperial with a physics degree and I would like to be able to join in their conversations sometimes.
• I like atoms
…there is a problem about how we, as citizens, relate to science…
The image of science:1Mad 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".
His experiments invariably go awry, with poor old Beaker usually being blown to bits or electrocuted. BBC 6/9/2004
The image of science:2Science Gone Wrong
The final touch… What! BANG!
Alex Noble (Age 9)
The image of science:3An un-scientific experiment
Scientist
……… Scientist
In contrast…
• A room full of people who want to learn about science
• Helped by volunteers
• In a world where ignorance makes us powerless
Tonight’s talk
• The scale and size of the Universe
• Electricity
• How Electricity works
• Atoms
• Light
Tonight’s talk
The scale and size of the Universe
or
‘How not to be boggled!’
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.
The imperceptible and the vast
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 gramSuch 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
The imperceptible and the vast
Measuring instruments extend our sensesTelescopes & Microscopes,
Weighing machines,
Devices sensitive to electricity & light,
Clocks
NPL: Enables people to trust measurements
Quantities and qualities that extend beyond our ability to
perceive them seem: imperceptible or vast
? ?Science helps us extend our senses
But we can still feel boggled!
Diameter:
12,800 km
Deepest hole: 10 km
Atmosphere: 10 km
The Planet Earth
Photo Credit: NASA
The Moon
Diameter
Earth:
12,800 km
Moon:
3476 km
Photo Credit: NASA
The Sun
Diameter: 1,390,800 km
Photo Credit: NASA
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’
Photo Credit: Powers of 10
Very Very Small
Very Very
Large
Powers of Ten (1)
1 metre
1000 m
1000000 m
1000000000 m
1000000000000 m
0.001 m
0.000001 m
0.000000001 m
Can you see the problem with very small and very large numbers?
Powers of Ten (2)
Very Very Small
Very Very
Large
1
1000103
106
109
1012
1015
1000000
0.00110-3
10-60.000001 1018 1024 1030 1036
1021 1027 103310-15 10-9
10-18 10-12
100
Powers of Ten (3)
Very Very Small
Very Very
Large
1 metre
103
106
109
1012
101510-3
10-6 1018 1024 1030 1036
1021 1027 103310-15 10-9
10-18 10-12 1012
1000000000000 m
0.000000000001 m
Powers of Ten Length Scale in metres
Very Very
Large103
106
109
1012
101510-3
10-6 1018 1024 1030 1036
1021 1027 103310-15 10-9
10-18 10-12
?Very Very Small
100
Human Relationships
Atoms & molecules
Nucleiof atoms
Current estimate of the size of the
universe
Nearest StarLight YearTallest MountainNanotechnology
Distance to the Sun
Diameter of the Earth
Diameter of a hair
MicrobesViruses
Quarks
Powers of Ten Length Scale in metres
103
106
109
1012
101510-3
10-6 1018 1024 1030 1036
1021 1027 103310-15 10-9
10-18 10-12 100
Human Relationships
Distance to the Sun
Atoms & molecules
Nucleiof atoms
Current estimate of the size of the
universe
Nearest StarLight YearTallest MountainNanotechnology
Diameter of the Earth
Diameter of a hair
MicrobesViruses
Quarks
Powers of Ten Global Warming
Very Very
Large
100
103
106
109
1012
101510-3
10-6 1018 1024 1030 1036
1021 1027 103310-15 10-9
10-18 10-12
Very Very Small
Human Relationships
The phenomenon of global warming involves physical processes with
length scales spanning 20 powers of 10!
Distance to the Sun
Tallest Mountain
Diameter of the Earth
Atoms & molecules
Microbes
Powers of Ten Nuclear Power
Very Very
Large
100
103
106
109
1012
101510-3
10-6 1018 1024 1030 1036
1021 1027 103310-15 10-9
10-18 10-12
Very Very Small
Human Relationships
Tallest Mountain
The issues surrounding nuclear power involve
physical processes with length scales spanning 25
powers of 10!
Nucleiof atoms
Distance to the Sun
Diameter of the Earth
Atoms & molecules
Microbes
Powers of Ten (time)Time scale in seconds
Very Very short
Very Very Long
100
103
106
109
1012
101510-3
10-6 1018 1024
102110-15 10-9
10-18 10-12
Time for a molecule to jiggle once
Light wave wiggles once
Earthmoves once
around the Sun
Estimated time since the big bang
Age of the EarthEnd of last ice age
Lifetime of a Civilisation
A human lifetime
Fastest response of human
eyeSound
travels 1 metre
1 second
The Universe
Its very big, but full of very small things
? ?
Tonight’s talk
• The scale and size of the Universe
Its very big, but full of very small things
• Electricity
• How it works
• Atoms
• Light
Electricity
Electricity
Electromagnetic waves
Electricity
Heat
How it all fits together…
Atoms
Eeeee - lec- tric-ity Electricity
Electricity
Some experiments…
Lets take a look at some odd phenomena…
• A balloon and a piece of paper
Lets take a look at some odd phenomena…
• If I balance my glasses carefully…
Even a sausage…
• Sausages…
…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’
• 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 simple scientific instrument: The gold leaf electroscope
The Van de Graaff Generator
Photo Credits: Katherine Robinson and MIT
• Scientists can develop machines to automate and amplify the ‘rubbing’ process with the balloon
The Van de Graaff Generator
It is not important to understand how a Van de Graaff generator works
PictureCredits: http://www.ikp.uni-koeln.de/~3T/tandem-prinzip1.htmlhttp://science.howstuffworks.com/vdg1.htm
The Van de Graaff Generator
It is not important to understand how a
Van de Graaff generator works
The Wimshurst Machine
Sorry: I cannot explain how a Wimshurst Machine works!
Photo Credits: Wikipedia and http://www.coe.ufrj.br/~acmq/electrostatic.html
Electrostatic Generators
• People have been doing this for a long time…
Photo Credits: http://www.ikp.uni-koeln.de/~3T/tandem-prinzip1.html
Conclusion…
Electricity is present inside ALL matter
Its ‘influence’ can be communicated
across ‘empty’ space
Tonight’s talk
• The scale and size of the Universe
Its very big, but full of very small things
• Electricity
It’s everywhere!
• How it works
• Atoms
• Light
Not Stuff • the gaps in
between matter• fields
Stuff • matter
How do we describe the world?
How do we describe the world?
How do we describe the world?
Not Stuff (Fields)• Fields
GravitationalElectroweakStrong
• Extend throughout space
Stuff (Particles)• Atoms
• Electrons• Neutrons• Protons
• Very small
We need to know about both particles and fields
Two different kinds of physical entity
How do charged particles interact?
It’s a three-step process…
Particle
with electric charge
Particle
with electric charge
Interact by meansof an electric field
…but the steps happen very quickly
How do we describe the world?
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 repelIf particles have different signs of electric charge they attractThe forces (attractive or repulsive) get weaker as the particles get further
apart.
Tonight’s talk
• The scale and size of the Universe
Its very big, but full of very small things
• Electricity
It’s everywhere!
• How it works
There are ‘particles’ and ‘fields’
• Atoms
• Light
Electromagnetic waves
Electricity
Heat
How it all fits together…
Atoms
Atoms
Atoms
Protons, neutrons and electrons normally exist inside atoms
Atoms are small• Think of a millimetre
Atoms
1 mm
0.1 mm0.01 mm0.001 mm
• 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
Photo Credit: http://www.morguefile.com ID = 104101
The electrical nature of matter
AtomsInternal Structure
How are atoms made?
proton
Interact by the short range ‘strong’ force – not electrical
Electrical Repulsion
How are atoms made?
Atomic Structure
Electrons• ‘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
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, aand as near to the nucleus as they can
The electrical nature of matter
ChemistryAtoms, 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
H
Atoms &… Molecules
H2
N
N
• A molecule is a collection of atoms stuck together electrically.
H
H
O
H2O
H
N2
Atoms &… Ions
• A ion is an atom or molecule which has lost or gained an electron.
O HH −
The electrical nature of matter
Solids
Atoms in solids
• Atoms can be imaged on a surface
Photo Credit: Patrick Josephs Franks: NPL
The electrical nature of matter
• 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
The electrical nature of matter
Mechanical Properties
Atoms and mechanics
• 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
The electrical nature of matter
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
The electrical nature of matter
Magnetic Forces
Magnetism
Electric
&
Magnetic
• 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
The electrical nature of matter
How the balloon affected the paper…
Odd phenomena…
• A balloon and a piece of paper
Odd phenomena…
• A balloon and a piece of paper
Tonight’s talk
• The scale and size of the Universe
Its very big, but full of very small things
• Electricity
It’s everywhere!
• How it works
There are ‘particles’ and ‘fields’
• Atoms
They’re everywhere! And they are all electrical!
• Light
The electrical nature of matter
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 meansof an electric field
…but the steps happen very quickly
The nature of interactions (1)
Analogy with water level and water waves
Tonight’s talk
• The scale and size of the Universe
Its very big, but full of very small things• Electricity
It’s everywhere!• How it works
There are ‘particles’ and ‘fields’• Atoms
They’re everywhere! And they are all electrical!• Light
An electro-magnetic wave
Electromagnetic waves
Electricity
Heat
How it all fits together…
Atoms
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.
Homework
• 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
HertzKilohertzMegahertz
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? OKA comment? OKA 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
See you next week!
Don’t forget your pencils and badges!
Goodnight
Goodnight