The Living Earth
Book: Physics and Technology for Future Presidents
Class 1: January 14
Science is fun!
• Twinkies turn gray after 24 years
• Donut stays the same for 2 years
• The Smoking Fry
o Different menu options fries stay the same 5 years later
Politics of Science
• Airport Security
Air Quality Air quality sensors in Boston, Waltham what pollutants are in the air?
Touchfoils Mayor’s office in Boston, bookstore, grocery store, etc.
Ecologial Footprint of Agriculture:
Designing research on
• Types of lights
• Crops, etc…
• Cost effectiveness
• Ecological impacts
• CO2, etc… emissions
“Science” is curiosity, is a way of “knowing”, finding patterns
• Science—systematic inquiry into natural phenomenon;
• Goals of a Scientific Inquiry
Scientific Community Critique
(experiences data, phenomena, systems and events in the world)
Patterns in observations (generalizations, laws, graphs, tables,
formulas) Models (hypotheses, models, theories)
What was the impact of Hurricane Katrina?
• What made it tough? Storm surge! BIG hurricane
Category 1 storm: Hurricane Sandy why it was so destructive because of storm surge
Ocean levels 20 ft. above normal
Tree cover in Mississippi during Katrina:
Gray: something urban
*a lot fewer trees! After the fact
What happened to all of the trees? Some still there
• Salt water
o Native trees made it (used to salt water), imported trees died
o Wasn’t wind or damage but was salt water
o Salt water takes water away from roots and tree cant get enough water
o Native species trees stayed
o Maples and oaks that weren’t native to area
o Boston 40% maples are not native
What is the value of green space?
Fukuoka Building, Japan
• Each floor just trees
Chicago housing developments
• One side of complex Dreary (no green space), one side with trees
• Good urban planning can be beneficial and cities don’t always consider
• Women: if you were on the green side of the building, you weren’t as mentally
tired and in better health & there was less violence
• Green space matters a lot!
• Hospitals: you get better if you can see a tree out the window 2 days faster
• People on the green side can focus better and get longer attention spans
• Baltimore has a lot of pavement around schools
• 40% of Baltimore schools have no schools around them
How about income and biodiversity?
• Impact of climate change around fisheries and coral reefs
• Coral reefs: as carbon dioxide builds up in the atmosphere, we are increasing
acidity in the ocean, high acidity dissolves calcium
• Study in US: how has ecology shifted?
o Now focus on studying cities largest footprint on the planet as far as
ecological cost and income levels.
o Biodiversity (amount of life in an area) As income levels go up, biodiversity goes up.
• House with big yard around more space
In a city, not as much.
*Public policy decision
People who live in high biodiversity, have better health
Correlates more than income levels!
1995 heat wave in Chicago:
• 106 degrees for several days in a row, high humidity
• became a state of emergency
o 23 hospitals had to stop accepting patients
o 739 deaths directly attributable to the heat
• wasn’t about heat as it was about something else
• Men were twice as likely to die as women, African Americans and Latios as well
o Experts assumed that female victims and the poor would outnumber male
victims in the heat wave deaths
o Women more likely to be elderly and live alone
o Not afford air conditioning
• Determining condition!
• If you had a park nearby and if you knew your neighbors
• A social Autopsy of Disaster in Chicago: Heat Wave – Eric Klinenberg
o 1999 – similar heat – city sent people to check on groups… 110 people
died – far below typical during heat waves
o only 6 people died in green space
• If all the ice melted…
• 216 foot sea level, average global temperature 80 degrees Light color: current borders
CO2 levels and temperature
2 stories: temperature follows CO2, or CO2 follows temperature
• From patterns, scientists develop theories and models that explain the patterns
seen in the experiences (observations).
• Explanations answer the “how” and “why” questions of science; they account for
many patterns that are seen in a greater number of observations.
• Scientific explanations are supported by a large evidence base and explain a
diversity of phenomena.
• Temperature drives CO2 Article
Arctic Sea Ice • Polar ice cap over 20 years
• Getting smaller and smaller each year
• White area: older ice been around longer, thicker, so takes longer to melt
• Gets small
• Cold snap directly correlated
• What drives weather is temperature differences
o Hot at equator, cold at poles
o Air likes to go hot to cold
Refrigerator cold air sinks down, warm air goes in
o Ice is a good reflector, when it goes away, left with water water absorbs
Ex. Wear ski goggles
o Big temperature deviations in warmth at north pole because ice is going
o Recently hit arctic ice minimums changes temperature gradient for whole
planet because warmer at north pole
o Equator hasn’t changed much
o Melting Arctic Ocean ice > darker surface > more solar radiation
absorbed > excess heat released especially in Autumn
o This decreases the temperature gradient and pressure gradient across the
jet stream boundary of the Polar Cell between the Arctic and middle
o With all of ice up there wind patterns start up – whirling around, polar
It is trapped up there because its cold
End up creating a low pressure center circulating
As it starts to warm up, the north pole, the wind pattern shifts
The jet stream drives our temperature,
o This diminished north/south pressure gradient is linked to a weakening of
the winds associated with the polar vortex (Polar cell) and polar jet stream.
o This weakened polar jet stream has larger loops in it, and it is the loops
especially which cause large storms.
o The loops also are longerlived, and as the southern ends can extend
further south now, they make for more frequent slowmoving intense
winter storms, and at the same time, longer and more extreme heat waves,
depending on where you are in these meandering loops
o The larger “loops” in the polar jet stream also mean that storms move
slower, delivering more energy to any given location. Wind patterns shift as North pole warms up
Negative Arctic Oscillation conditions are associated with higher pressure in the Arctic
and a weakened polar vortex (yellow arrows). A weakened jet stream (black arrows) is
characterized by largeramplitude meanders in its trajectory and a reduction in the wave
speed of those meanders.
As temperature difference decreases, jet stream meanders.
North of black line, cold, south= warm
Recently, Polar Vortex became lopsided and diffused
The Polar Jet Stream and Weather
Dr. Jennifer Francis
Beijing Air Quality Hazardous* 1400 in Beijing
Olympic runners were concerned in China
Past outbreak beat 755
EPA Air Quality Index
Unhealthy for Sensitive Groups: 101150
Very Unhealthy: 201300
The readings in Beijing topped out at 755.
What does that do for your lungs?
8 Volunteers • 20 hours
• Air filter through a breathing simulator
• low 40 micrograms per cubic meter of particulate matter is safe
• 3 times as much!
• 122 micrograms per cubic meter. A ton of particulate matter!!
o Increase risk of cardiovascular disease significantly
o If you live in China, you will live 5 years less
Matters on neighborhood and quality of air
US air quality overall good
Who breathes in the most? Taxi drivers
*Most polluted all in developing countries
Cuyahoga River… Pittsburgh, 1969
• 3 rivers that come together, this event sparked the Clean Water Act
• river caught on fire, not a lot of regulation in massive steel town
• Coal production and consumption have tripled since 2000 • steel output is expected to have reached around 720 million tons (793.66 million
tons) in 2012
o over five times the 2000 rate.
Country size relative to population
Class 2: January 16
Growth of Walmart & Sam’s Club, flowingdata.com
• Started in AK and grew slow
• At peak 133 stores a year
• 35% of retail market in US they are everywhere!
• 4393 stores 2008
▯will use for air quality labs Dot Map of 2010 census
• see where people live
• City sprawl, impact urban sprawl
• Most “Sprawliest” in SouthEast
• least in SouthWest
Map of UC Berkeley mapped by zip codes of carbon emissions
• pattern: major cities have ring around it of high levels of CO2 from traffic
• cities produce much less pollution/ carbon dioxide emission as opposed to
• ex. Atlanta core, highest population density,
o breaks down on where theyre using fuels
• ex. Boston wealthiest and least wealthiest
o as income levels go up, the amount of CO2 emissions go up
o inversely proportionate to population wealthier cities have less
population have to travel more driving, generally no public transportation
Worldmapper take geographic area of company and changes with variable you’re
• country size relative to population, also imports
o ex. Germany imports lots of fruit, China imports little
• a lot of people country enlarges
• China, enlarges; India, enlarges; US stays relatively same
40% of U.S. public couldn’t find US on a map
• 70% couldn’t find France
• ways of visualizing data in ways that make sense
• 7,114,000 world population
• over time, every time you see a blink
• every time it changes color, emitted 1000 tons of carbon dioxide, a gas
• also when people are born and when they die
dies every 12 sec. born every 7.4 seconds
population in US should be decreasing but is going up due to
Person dies every 3.6 seconds, person born every 1.3 seconds
More than enough to hasten population growth
* China is similar
o European countries are similar to US
Scientific Literacy: Role of Popular Media All great visuals that science produces many of them get twisted in media
ex. Code in movies
• One of the major aspects of scientific literacy was the ability to understand and
critique reports and discussions of science that appear in the popular media
• An increasing proliferation of images and symbols via hitechdriven media
entertainment that is deliberately designed to meet the public imagination about
• the blurring of fact and fiction by visual media has corroded the public’s critical
thinking skills and has hindered the development of a scientific literate citizenry
Movies get people excited about science, ex. StarTrek, Gravity
But it can also alter views
Movie, Twister, science is awful
Fictional depictions of science in film and television encompass more than just
• focus on the production presentation of a plausible and realistic image of science
The Core analyzing can tell who sees movie can reverse 2 weeks of lessons
Watch film: 10.5 Apocalypse, Jurassic Park
Earthquakes 2 big plates hit and collide, well done in movie
• MidWest was under water at some point, no icecaps = more water on planet
• Found fossils
Research on the production of modern science fiction visual media
• film makers strive to ensure that their depictions of scientific phenomena have a
basis in reality
• If it is not based in reality the audience tunes out – too fantastical
• It is film’s ability to create plausible scientific phenomena that captures the
• to achieve plausibility many film makers design images, even unreal images, to
correspond to ‘cues’ with which viewers have seen.
• go in straight lines, get really big
• plate tectonics, move at length of fingernails growth per year, ~2 in. per year
• talking about Earth’s magnetic field
• everything in clip is really good as far as description goes until microwave part
sun does throw particles at us, solar flares, astronauts must be careful, magnetic
field accelerates • microwaves almost none sun is yellow because it gives off all energy in
o microwaves have low energy they excite water molecules/ vapor to dry
things out ex. Microwave will blow up and then get very hard
o why coffee gets hot and mug doesn’t
• People think sun is bad and gives microwave everything wrong with science
o If you can fit in a microwave, you would not get sunburned
o Ultraviolet rays burn your skin
o Same material as glass cant get sunburned through glass glass absorbs
o Low energy compared to ultraviolet beam lot of energy to heat up water
o Tin foil in microwave
Inconvenient Truth Movie
In Jurassic Park the viewer sees unreal animals (i.e., dinosaurs) that match the
movement, appearance, and sounds of animals with which audience members have
• “realism” of such images audience members tend to perceive these images as
realistic even though they are not actually real (Frank, 2003).
• Then these “unreal” images have plausibility and explanatory power which can
influence their ideas and understandings of scientific phenomena (Dubeck,
Moshier, & Boss, 2004).
• Heroes in many movies have scientific expertise
• Often explain ideas correctly that the audience probably understands
o Lays foundation for future “non”science
• “non”science explanations have predictive power
Movies influence one’s ideas by:
• Creating Plausibility
o Grounded in accurate science
• Creating Realisticlike images
o Interact with or look correct
• Creating Believability
o Explanations that have predictive power
The Day After Tomorrow
• Rapid climate change?
o Based in reality?
o Real or “Reel” science? • Is this true? Or even possible?
o Nuts, noway, bad science
o Sort of true
o Mostly true (oh, say about 80% true)
o 100% right, no doubt about it
What “Nemo” looked like from space
Hurricane Sandy 800+ miles in diameter, looks like a “comma”, characteristics of
hurricane and Nor’easter
Top 7 snow storms for Boston:
Biggest snow storms have happened mostly in last decade
2003: biggest storm around 2829 in. HUGE
1978: 2 blizzards in a row 27 in 2005: 22.5
2013: 24.9 in.
massive snow storms!! All recent in past 30 years
Climate Change predicts more heavy precipitation events
Includes snowfall, rainfall= all winter events
Goes through a cycle like everything else
Weather is a pattern
Trend has been a bit upwards
Steady through 70s80s but BIG jump recently
Every precipitation event produced a lot of precip
Jet Stream…moves the storm
The Perfect storm category 3 pressure storm
Problem is that jet stream is messed up (high level winds)
energy and motion are basically the same thing if you move really fast you have energy
Storms can pick up energy in jet stream energy means precipitation
How a Nor’easter forms:
2 competing currents:
jet stream pulls up until England
from the North there is another cooler water current
from ice melting, current flow down cold water denser than warm water
if something is more dense and hits something less dense= mass issue
warm water comes up the coast, cold water comes down
where they hit is a perfect spot for storms to strengthen
gain energy from a temperature difference
cold fronts= synonymous
climate change comes in
Warm water…means energy source
darker red= hotter
in last 910 yrs, blue current has been getting further south
ice melts, 3435 degrees, denser= comes down further south to intersect redder water to
bend jet stream which makes it weaker problems: for the last few years, more turtles have to be saved (cold shocked) in
Winter Nor’easter Formation
impacts where nor’easters will initially strengthen
1. storms miss us and heads out to sea
2. gets stronger and gets entire east coast
infinitely cold area= massive amounts of snow and ice
60% of US now has snow on the ground
heading out to sea a bit but more snow on East Coast
ideal snow storm:
low pressure center moving across country (Appalachians)
storms don’t like mountains moisture gets squeezed out of storm
Appalachians not as tall as Rockies hitting temp. difference feeds storms, they develop
and become a great big storm.
Characteristics of a bomb cycle
Bomb cyclones breed ferocious storms
Jet stream can be predicted
Right picture is storm
Typical Damage caused
Great damage with huge level winds
Beach erosion at high tide
*Billions of dollars for massive storms
**Damage will get significantly worse in the next 2030 years
Storms like Nemo will start happening every 510 years
Nor’easters and hurricanes are not the same
Hurricane is a warmcore
Nor’easters is a coldcore (winter time) cold air
Driven by temperature differences
Hurricane driven by evaporation water releases energy
Hard to predict
Nor’easter driven by temperature difference
Can predict up to 3 days in advance
As polar ice caps finish melting, likelihood of bad nor’easters is low? Tricky to determine
Comparing hurricane to nor’easter
Climate change we don’t know what it is really going to do
**Sandy is an exception to everything
Class 3: January 21
Airport Security • The smog has become so thick in Beijing that the city's natural lightstarved
masses have begun flocking to huge digital commercial television screens across
the city to observe virtual sunrises.
• The futuristic screens installed in the Chinese capital usually advertise tourist
Travelling through the airport: How do the Scanners work?
Popcorn and cellphones:
• 730 million people travel on passenger jets every year throughout the world
• 700 million pieces of their baggage are screened for explosives and other
In the United States
• Hartsfield–Jackson (Atlanta) held its ranking as the world's busiest airport in 2012
• ~88 million passengers (~250,000 passengers daily)
• 970,235 flights
• About 2500 flights/day
• That is about 2 flights per minute
Different Types of Detectors
• PI detectors sends powerful, short bursts (pulses) of current through the coil of
wire (25 – 1000/s).
– Each pulse generates a brief magnetic field.
• Use the fact that moving electric currents generate magnetic fields
– Magnetic fields induce currents and hence a new magnetic field in a
• If it hits metal the receiver “sees” the magnetic field pulse induces a current in the
Electricity and Magnetism
• The magnetic field generates a force on the electrons in metal in your pocket
causing them to move
• Generates a current
– Generates a countermagnetic field
– Lenz’s law
In 1819, Hans Christian Oersted
– A compass needle near a wire through which he could make electric
• Moving charge (electricity) generates a magnetic fields
The Earth is a huge magnet
• The nickel iron core of the earth gives the earth a magnetic field much like a bar
magnet. • Earth’s magnetic field is flipping
• Magnetic north will soon be magnetic south
• Not sure why this happens
• Happens about every 250,000 years, last flip was 800,000 years ago
Look inside a magnet:
• Magnetic substances like iron, cobalt, and nickel are composed of small areas
where the groups of atoms are aligned like the poles of a magnet.
• These regions are called domains.
• All of the domains of a magnetic substance tend to align themselves in the same
direction when placed in a magnetic field. These domains are typically composed
of billions of atoms.
What is an electromagnet?
• When an electric current is passed through a coil of wire wrapped around a metal
core, a very strong magnetic field is produced. This is called an electromagnet.
• Magnetic Levitation (Maglev) Trains
– Induced surface (“eddy”) currents produce field in opposite direction
3à Repels magnet à Levitates train
– Maglev trains today can travel up to 310 mph
à Twice the speed of Amtrak’s fastest conventional train!
Why aren’t there more Mag Levs
• Not compatible with existing track…..
• Tracks have to be wider than those of conventional trains
– provide enough surface area for the repulsive force to support the train
• Very expensive to build
– High power magnets are needed…
January 23, 2014
Chinese pollution reaches USA
LA experiences at least one extra day of smog per year because of nitrogen oxides and
carbon monoxide emitted by Chinese factories making goods for export
Winds blow westerly
Due to all pollution being blown across the ocean
It distributes up North (in cold) pushed out of atmosphere due to rain
Black carbon is an exception dust particles filtered out of atmosphere can be distributed
Sut has evidence that cardiovascular disease can increase up to 33%
Boston has no control over things in air
China’s good exports to the USA resulted:
7.4% increase in sulfur dioxide (what smog is called)
5.7 nitrogen oxide precursor to ozone formation
3.6 percent for black carbon
4.6 percent for carbon monoxide can kill you in high level, replaces oxygen in
*all due to exports for the US
Generally for the US they found a positive health benefit because the East US has a much
higher population than the Western states despite the China pollution
Manufacturing area of lower costs, reduction
*Article NYT Chinese Air pollution reaches the US
Metal detectors very good at detecting anything that has iron in it
detect all other items, using millimeters as opposed to exray frequencies
millimeter energy is a small enough wavelength that it wont hurt skin but can go
people worry about radiation buildup
o big Uproar airports are removing them
different type of detector in use Pilots are especially worries about it because they go through so often
xrays have limitations ie. If something is very dense like batteries are something very
dense you can hide something in something dense, swabs detect ions
3D printing preprint someone’s skull, weapons, food
The advanced imaging tenchology (AIT) screens passengers for metallic and nonmetallic
threats including weapons, explosives, and other objects conceals under layers of clothing
without physical contace.
2 types of scanners: millimeter wave and backscatter
Millimeter wave machines: use electromagnetic waves that bounce off the body to create
a black and white 3D image
This has a privacy filter that blurs facial features.
2 types of millimeter wave scanners:
active type – direct millimeter wave energy at the subject and then interpret the
reflected energy, throws beams of radiation at you
passive type read only the raw energy that is naturally emitted from the human
body or objects concealed on the body. No energy is directed at the subject and is
as safe as a digital camera for both the screener and the subject, reading radiation
as if comes off of you slower
has a coil inside that generates electromagnetic pulses to generate the millimeter
Penetrates your skin, and it gets a reflection back how much radiation is sent and how
much comes back. If it is an anomaly, you get flagged.
Millimeter machines, how?
Send radio waves over a person and produce a 3D image by measuring the energy
Human skin is all they want to show up and anything that is not human skin is
cause for alarm
o People worried about privacy, the people looking at images in other room,
now blurs faces
Because the panels move around you, this scan can take up to 40 seconds (usually
less) and there is a zoom option
o Software designed to blur your face
These are the ones that give you these images
Backscatter: these machines use low level Xray beans over the body to create a
reflection of the body
These images resembles a chalky drawing with facial features blotted out in their
Detecting particles, not sending anything back at you
Lots of information available on these
Where is the energy at on the spectrum?
Blue indicates region of millimeter wave energy.
Red indicates Xray BackScatter. Xrays penetrate well
Why the energy levels matter
As the energy gets higher in frequency and shorter in wavelength, the energy
eventually “changes” in the effect that it has on it’s targer.
This effect is called ionizing and it consists of subatomic particles or
electromagnetic waves energetic enough to detach electrons from atams or
Xrays scans, hits electron, electron either gets to a higher orbit or gets completely
Energetic photons can create tissue damage to skin
Millimeter energy, a lot of energy, millimeter radiation
Controversies: Safety and Privacy
Security advisors insist that the radiation exposure is equal to what passengers get
in a plane for two minutes at 30,000 feet than walking through detectors, sun
Scientists fear the volume of radiation may be safe for the entire body but not
directed at a small area
Kids, elderly, frequent travelers, etc.
Health Physics Society (HPS): A person undergoing a backscatter scan receives
approximately 0.005 millirems
Mrem, a unite of absorbed radiation
American Science and Engineering, Inc. puts it slightly higher in the area of .009 mrem.
Still really low
Is it safe?
1 mrem per year is a negligible dose of radiation
25 mrem per year from a single source is the upper limit of safe radiation
exposure, in a single shock
Using the HPS numbers, it would take
200 backscatter scans in a year to reach a negligible dose
1 mrem of radiation generally get less than 1 mrem a year
You receive 1 mrem from:
o Three hours on an airplane
o From two days in Denver or from three days in Atlanta
o It would take 5,000 scans in a year to reach the upper limit of safety
This is the concern that pilots have
May need to go through a scanner several times/day for much of
o A typical traveler would have to get 100 backscatter scans per week, every
week, for a year, in order to reach the lower end of safety limits.
Fullbody scanners deliver a radiation dose equivalent to what a standard man receives
every 1.8 minutes on the ground, or every 12 seconds during an airplane flight. An individual would have to receive more than 22,500 scans in a year to reach the
standard maximum safe yearly dose
New Ion detectors
Explosive Detection Portals
Explosive materials often release gases/particles
o Ion Mobility Spectrometry
o Mass Spectrometry
Cost $125,000 each, metal detectors very cheap
o Can detect almost anything w potential for an explosive
o ~10 years
Cargo Screening Systems
large xRay units with wide openings and heavy palletized capacity (3000 kgs)
fixed vehicle/container xray systems
vehicle/container portal systems
mobile truckmounted systems
explosive detection, fixed and mobile
Technology & Equipment
Handful of products: Rapiscan most used for baggage, large items in airports
Same technology for buses, subways, starting to be used ▯don’t want to slow train down,
detector is like a tunnel to detect particles and radiation of anything that could be
Highways archways fast lane, there’s a sensor, you pass through radiation
many false positives
high density things ion detectors are good
Mostly xray machines but have built in radiation
The Electromagnetic Spectrum ROYGBIV
January 28, 2014
Energy, Work, and Forces
Energy cuts across all fields
E = mc
How stars shine
What is energy?
Energy is the ability to do work (= force x the distance an object moves under the influence of the force)
or, energy is anything that can be turned into heat.
Heat is the energy due to the microscopic motion of individual molecules in an object,
measured by its temperature.
Heat (energy) is measured in
Calories, calories, joules, kilowatthours, watthrs
Anytime you have motion, you have energy, anytime you have energy you have
temperature, temperature means there’s heat
A. Power is the rate of doing work
B. POWER= WORK/ TIME
power is how fast you do work
C. JOULES/SECOND=watt (joule= energy/s)
D. FT LB/ SECOND=horsepower
(A)A horsepower is defined as a power rating of 550 ftlb/s.
1 horsepower is equivalent to 746 watts
Bat speed decreasing
(B) A watt is defined as a Newtonmeter per second, or joule per second.
A Newton: This is lifting a medium sized apple 1 meter (about 3.3 feet)
why cars have been going to more plastics lighter/don’t need as much power
Small units Calorie, ftlb, joule (J)
Moderate physical activity, small electrical appliances
Kwh, kcal, Btu
Food, home heating/cooling
Quad, Mtoe (megatonne oil equivalent), Mbbl (millions of barrels)
National and world usage – nuclear bombs…
Energy: Climate & Weather
Energy cuts across every discipline weather, tornados, etc.
Hurricanes getting stronger but don’t have as much of them
If we could harvest all that energy, it generates enough
power to power half the planet that many watts!
Global warming – redistribution of energy across the globe
Storms are the result of energy absorption and release
A category 1 hurricane with 90 mph winds produces
1.5 x 10 Watts.
This is equivalent to about half the worldwide electrical generating
Energy: Chemistry – Air quality
Worse in summertime when its hotter and drives chemical reaction
Energy cuts across all fields
Activation energy with a lot of energy, reactions happen;
something hot things are more likely to happen things moving
around and run into each other
Atlanta in particular has bad air quality
23 degrees in temperature difference has huge impact on
Energy needed for a reaction to occur
Heat and temperature is important
Average American 2700 Calories (recommended 2200)
Note the big C!
Really means 250,000 calories
Ex. Coke experiments
42 grams of sugar in a can of Coke 10.5 teaspoons
kids in school almost that much sugar in milk to get kids to drink it
which has more energy? Cherry coke or diet coke? o You can starve to death with 0 calories of Diet Coke
o Diet Coke floats, Cherry Coke sinks
Aluminum cans don’t rust
“C”alories must be multiplied by 1000 which calories are actually injested energy
calories are actual calories
How much food will get you so many miles
Nutrition labels tell you about the energy content of food
Conversions: Fat: 9 Cal/g
Carbs: 4 Cal/g
Protein: 4 Cal/g
This product has 72 Cal from fat, 48 Cal from carbohydrates, and 32 Cal from
sum is 152 Calories: compare to label
152 Cal = 636 kJ:
enough to climb about 1000 meters (64 kg person)
1 Cal = 4.134 Jules Energy & Food
Average American 2700 calories (recommended 2000 2200)
7 acres to support one American
uneven! We consume more calories
1.5 acres to support one African
The world appears to have enough carrying capacity to support around 10
maple trees gradually shifting up to Canada maple syrup in trouble
croplands shrurk in some areas, grew in others
if we don’t do something with food supplies, will planet be able to get back up to
1012 Mil. People?
Chocolate bacteria in intestines
Energy can be stored as potential energy
A wound up alarm clock
Toyota Prius battery
Gravitational Potential Energy ie. Roller coasters lost energy in lots of places
Gravitational Potential Energy is the energy an object has because of its position relative
to the earth.
Potential energy how high you are above the ground, lowest point in a system
grav. PE = weight x (height above ground)
ex. Glen Canyon Dam in Utah uses the potential energy of the Colorado River water to
produce more than a 1200 MegaWatts or power.
We can produce a ton of power with water! Dam it up, let it flow, a lot of mass falls, get a
lot of potential energy, and kinetic energy which turns turbines and you get power!
A sliding box is moving, therefore we say it has motion energy or Kinetic Energy.
Other examples of Kinetic Energy:
In roller coaster, ball moves and spins (rotational energy) if ball spins, no friction
Not losing energy when it spins
Conservation of Energy
Energy is not destroyed.
Energy is transferred between objects. (Energy in my body is used to slide a box across the table.)
Energy is converted from one form to another.
(Energy in the box is converted to heat as the table heats up from the sliding box.)
Why this matters?
Climate is warming up… Energy has to go somewhere…
Hurricanes, storms, etc….
Adding energy to the plant energy has to go somewhere
Energy & Power
Global human energy use could be supplied by covering approximately this area of a
tropical desert with solar cells converting 10% of sunlight to electricity.
how do you distribute energy? Cant run high voltage areas everywhere
Why is it that chocolate chip cookies have 8 times as much energy as the same weight of
TNT? Why do we use oil?
Problem with energy production: batteries
Have to store energy somewhere in a chemical form
Solar energy convert to electricity where does that go?
TNT: per gram ~0.6 calories out of TNT per gram
Choc chip cookies: 5 calories per gram, a lot more energy per mass than TNT
8x more energetic than TNT
gasoline 6 calories, 15 times more energetic why it powers cars
Why Blow up something with TNT and not a cookie?
In both cases, the energy stored is the chemical energy stored in the atoms, as if
it’s stored in compressed atomic springs.
We can blow up a building better with TNT than with chocolate chip cookies
TNT can release its atomic springs much, much faster.
It generates heat, and the TNT immediately becomes a hot, high pressure
gas that expands and drives everything out of its way.
A gram of TNT typically releases its energy in a microsecond.
A cookie is full of loose springs releases energy slowly over time
TNT does it very very quickly
Power= energy/ time so faster you release energy, you get more power
The cookies have more energy, but the TNT releases much more power –
Power = rate of energy release: Joules/second
Faster you do it, more power you get
I could feed all of you choc. chip cookies and give you sledgehammers, and
you could all eventually bring a building down –
But it would take time for the food to mix with the acid in your stomach and
enzymes in your intestines, and then the digested food would mix with oxygen
you breathe in and store in the red blood cells in your blood.
By contrast, TNT contains all the chemicals it needs to explode, so it goes off all
at once. Gasoline has 1.5 2 times more energy per gram than cookies, alcohol, or coal
• That’s what makes it so valuable, particular for cars!!
Gasoline: 10x more calories, even more than cookie!
Uranium (nuclear fuel): 30 million times greater than TNT
January 30, 2014
Why do lakes freeze top down?
40% ice covered Lake Michigan, up to 70% by next week
The temperature at bottom of lake Michigan will always be 40 degrees Fehrenheit unless
it is completely frozen, why?
Water is most dense at 4 degrees Celsius
Water freezes it expands when it gets colder (expands turns to ice)
Water heats up it expands when it gets warmer (turns to steam expands out)
At 4 degrees Celsius, 40 degrees Fahrenheit, water is most dense and sinks
Water is the only liquid that does this!
Lakes freeze from top down because when you get done to 0 degrees Celsius, water is
less dense and floats to the top, if lakes froze bottom up, fish would have tough time
Ice further insulates the water
Cork similar property, expands when you squeeze it
Climate Change in 15 seconds
Why does global warming exist because its so cold?
NASA video temperature anomalies over past 50 years
Blue: temperatures below planets historic average; yellow= above
80s/90s gets warmer but still has cold spots, might end up being less or more pronounced
Have you seen memories form…
The team put fluorescent tags on messenger RNA (mRNA) molecules that code
for betaactin, a protein believed to be crucial for the formation of memories
Track molecules in a mouse’s brain see them moving, when they part
themselves= memory formation
This process allows betaactin protein to be synthesized at specific times and
places and in specific amounts
Done in mice… though similar in basic brain structure to humans
Electric cars have gotten a lot of press…so why not use them?
Batteries are fast and reliable, good for starting car but don’t have the energy content of
gasoline to drive the r.
Batteries: .03 calories
Gasoline: 10 calories
Gasoline stores so much energy
Can release it very quickly
Can let car run for 2 min. after its dead to charge up Very quiet
Battery stores the energy and can release over time, rechargeable
Gasoline has 340 times more energy per weight than battery. But a battery can be
more efficient: 85% vs 20% for a gasoline engine.
So factor of 340 è 80.
A gallon of gas weighs 6 lbs, so 16 gal ~ 100 lbs in a typical gas tank. At 20 mpg,
range is 320 miles. Say you’re only going to use the car to go short distances, and
are content with a
range of 60 miles.
Then the necessary battery weight would be
100 lbs x 80 x 60/320 = 1500 lbs ~ 8 people
batterys are heavy still cant make batteries light and more expensive
oil is relatively cheap
How about costs? Electric Wins right?
Pbacid battery costs $50 for 50 lbs
$1/lb ~ 10¢/kWhr
If electricity costs 15¢/kWhr
25¢/kWhr including battery costs
If gasoline costs $3.50/gallon = 56¢/kWhr
Batteries are cheaper per kWhr as long as the price of oil stays high.
A good computer battery holds much more energy
$100/lb è $4/kWhr, 8 x cost of gasoline
batteries can hold a lot of energy
Electric cars can cut down on gasoline exhaust and need to deal with unfriendly foreign
but they make sense economically only if
we are willing to
carry around a lot of weight and
not go very far.
Hence the concept behind the Chevy Volt
There are also ecological costs
No emissions out of the tailpipe
Emissions shifted to powerplants
Talk more about this when we get to
Electric car no emissions, all running on battery
Problems: energy needs to come from somewhere depends on where you get that energy
and ecological footprint.
Energy in MidWest comes from coal power plants
Here in East, electric cars are better with energy coming from windmills, etc.
Ads for electric cars say zero emissions but its “out of the tailpipe” How about hybrid cars? Best of both worlds right?
Inefficiency in standard cars comes from changing speeds. Car engine running at
constant speed is 23 x more efficient.
Why cars get better gas mileage on highways than in city driving….
Hybrid uses a gasoline eng