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New Core Curriculum: Foundations of Scientific Process Energy: a Prerequisite for Life

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gamma rays X-rays Ultra-violet Visible Infrared Microwave Radio waves Many wavelengths of light outside of visible Astronomers must consider the full EM spectrum 10 m -15 1000 km EM radiation

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What does the Emitted Wavelength of EM Radiation Depend on? Temperature of the emitting object

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So What Makes Life on Earth Possible? The Sun Emits Visible EM Energy Which Provides Global Climate On Earth That Is Conducive To The Formation And Sustenance Of Life As We Know It

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Stars are massive gaseous body in outer space that generate energy through nuclear fusion and therefore emit visible light; Solar energy comes from the rearrangement of protons and neutrons this energy powers the stars petawatt (10 15 watts)

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Energy input = Earths output 1) E in (from the Sun) E out 2) Reflectivity (Albedo) 3)Earths surface & Atmosphere (Greenhouse gases)

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Brightness (E in ) depends on the distance of emitting object: Of b, L, d -- which are directly measurable for astronomical sources? E in = Inverse Square Law: Measuring b and knowing L yields d

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What other forms of energy exist besides EM radiation ? What is Energy? Energy is defined as the ability to do work and produce/transfer heat New Core Curriculum: Foundations of Scientific Process EM radiation is not the only form of energy that exists and that is important for modern life!

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ENERGY = WORK + HEAT Dont Confuse Power, Work & Energy Energy: In colloquial language, ENERGY is equated with vigor, liveliness and vitality In science, ENERGY is defined as the ability to do work and transfer heat

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WORK not concerned with a nature of the task, tiredness, etc. defined as force acting through certain distance units: Joules, calories (cal), nutritional Calorie (kcal) Dont Confuse Power, Work & Energy

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HEAT energy of atomic / molecular motion this energy always flows from warmer to cooler object units: Joules, calories (cal), nutritional Calorie (kcal) Dont Confuse Power, Work & Energy

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POWER P = W / t work being done in a certain time frame units: [J/s = Watts, horse power: 1 hp = 746 W] Dont Confuse Power, Work & Energy

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Energy Can Be Classified As Kinetic (KE) or Potential (PE) Energy PE can be converted to KE and KE can be converted to PE E total = KE + PE

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Most technological devices are energy-form converters

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out there, here s the skinny Energy is never created or destroyed, it just converts from one form to another, the total energy always remains constant Law of Conservation of Energy Every time work is being accomplished or heating is taking place, energy transfer is taking place Energy is never created or destroyed

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Mechanical energy Chemical energy Radiant energy Electrical energy Nuclear energy Various Forms of Energies

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Mechanical energy created by a physical movement, it is characteristic of machines in motion; Chemical energy energy involving chemical processes (typically oxidation); plants create and store chemical energy from radiant solar energy ; Electrical energy generated by the flow of electrical charges along a conducting material; Nuclear energy form of energy originating from collisions of atomic nuclei. Radiant energy EM blackbody radiation emitted by all visible objects in the universe;

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Activity: Chemical Energy & Energy Balance in the Human Body

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FoodServing SizekJkcal Skim Milk8 oz (250 g)34783 Whole Milk8 oz (250 g)610146 Mixed Vegetables cup (125 g)24759 Broccoli cup (125 g)6315 Yellow Corn1 ear447107 Fruit Cocktail cup (125 g)23055 Whole Wheat Bread1 slice27265 Baked Potato1 item920220 Black Beans cup (125 g)477114 Lean Ground Beef3 oz (84 g)966231 Ground Turkey3 oz (84 g)836200 Butter1 tbsp (15 g)451108 Olive Oil1 tbsp (15 g)497119 Canola Oil1 tbsp (15 g)502120 Sugar1 tsp (5g)6315 Beer12 oz (375 g)493118 Whiskey1.4 oz (44 g)432132 Energy Input Energy values of foods can be estimated based on the content of: Carbohydrate:17kJ (4.0 kcal) of energy /g Protein:17kJ (4.0 kcal) of energy /g Fat:38kJ (9.0 kcal) of energy /g Alcohol:29kJ (7.0 kcal) of energy /g

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Activity: Chemical Energy & Energy Balance in the Human Body Metabolic Energy: Energy needed to maintain life. Based on sex, weight, and age. For a young adult female, the metabolic rate is ~100kJ per day/kg body weight. For a young adult male of the same weight and age, the figure is about 15% higher

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Activity: Chemical Energy & Energy Balance in the Human Body Muscular Activity: Energy consumed when muscles contract (writing, walking, playing tennis, or even sitting in class). It is typically anywhere from 50% to 100% of the metabolic energy depending on lifestyle: Lets say the aforementioned female never lifts anything heavier than a textbook.

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Activity: Chemical Energy & Energy Balance in the Human Body Metabolic Energy + Muscular Activity = kJ/day (kCal / day) So thats the number of calories or kJ / day you need.

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Activity: Chemical Energy & Energy Balance in the Human Body Lets compare the number of calories or kJ / day you need with the energy used by a lightbulb.

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Activity: Chemical Energy & Energy Balance in the Human Body Metabolic Energy: required will vary depending on environmental conditions.

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Activity: Chemical Energy & Energy Balance in the Human Body There are 7 billion humans on earth. You now know how many kJ of energy the average human needs per day What is the total energy required for all humans on earth? What percent of the energy given by the sun is this?

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New Core Curriculum: Foundations of Scientific Process Key sources of energy used today Future sources of energy

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In the United States Today the major sources of Energy are Fossil Fuels, Nuclear & Hydroelectric

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octane, a hydrocarbon found in petroleum Fossil Fuels Like Natural Gas, Coal & Petroleum are Chemical Sources of Energy

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Only a small percentage of our energy comes from non-chemical sources like hydropower & nuclear

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Fossil Fuel Reserves (billion oil equiv) CountryOilcoalgasoil + coal + gas Total with shale US2112843413393839 Russia6083128011711626 China4844213503519 Australia1304185553 India54897502 Saudi Arabia262040302 Iran1360162298 Canada179329220 Qatar150152167 Iraq115019134

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Future Carbon Dioxide Emissions ?

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Conservation of Energy & Sources for the Future: Solar energy radiant energy from the Sun Geothermal energy energy stored beneath Earths Crust Hydrogen energy hydrogen reacting with oxygen releases clean energy (water is by-product) According to the US department of Energy, US currently consumes ~ 1.06 10 18 J of energy per year

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Solar Thermal : (100kW to 30mW power supply) Pro: clean. Con: unstable energy production (sunlight less than 50% of time), low energy efficiency, currently heat is taken up by oil and converted into steam to run turbines, the efficiency is 50%, which could be improved by using new material as heat storage media. Geographic limitation - needs large area to install (only 50% of the total area can be used for solar panels). Alternative Energy Sources SOLAR TECHNOLOGY

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What controls local climate? What makes it variable? differential regional heating due to Earths spherical surface: the same amount of radiation is spread over larger surface in north and south latitudes vs. at the equator.

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Atmospheric Circulation sets up convection currents Coriolis force: due to rotation of the earth acts at right angles to the direction of motion (deflection to the right in the Northern Hemisphere and to the left in the Southern Hemisphere)

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Pro: clean (no CO 2 ), cheap to run (comparable to burning coal taking into account of carbon tax in the future). Con: expensive to set-up, intermittent productivity, hard to store resulting energy, geographic limitation due to space. If we scale up the current production by 80 times to make up for 1 wedge of carbon reduction (Socolow and Pacala 2006), it will likely interfere with the ecosystem and maybe even the climate system by changing wind pattern. Alternative Energy Sources SOLAR TECHNOLOGY Wind power: (modern windmill ~2 mW power supply)

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Bio-fuel: Biofuel is defined as solid, liquid or gas fuel derived from relatively recently dead biological material and is distinguished from fossil fuels, which are derived from long dead biological material. There are two common strategies of producing agrofuels. One is to grow crops high in sugar, and then use yeast fermentation to produce ethyl alcohol (ethanol). Second is to grow plants that contain high amounts of vegetable oil, such as oil palm, soybean. When these oils are heated, their viscosity is reduced, and they can be burned directly in a diesel engine, or they can be chemically processed to produce fuels such as biodiesel. Alternative Energy Sources SOLAR TECHNOLOGY

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Bio-fuel: Pro: readily applicable, use unlimited source of solar energy. Con: With the current technology and specific situation in the US, biofuel remain expensive, harms the ecosystem and still produce CO 2. Brazil and India could benefit from extracting ethanol from sugarcane that has much higher sugar content than corn, which is the main biofuel crop in the US. Alternative Energy Sources SOLAR TECHNOLOGY

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Alternative Energy Sources GEOTHERMAL ENERGY making use of Earths internal heat geyser

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Hydrogen economy: (100kW to 30mW power supply) Pro: more efficient than fossil fuel for the same amount of energy output. Coal gasification has incentive due to the large reserve in the US and theoretically its cleaner than directly burning coal. Con: hard to generate, hard to carry around, and traditional production methods using fossil fuel still generates CO 2 by product. Coal gasification plants could generate hydrogen much cheaper (through bring coal to 1300-1400 C and react it with oxygen to generate CO, H 2 and CO 2, or called syngas), given that the CO 2 generated can be captured and stored properly. Or the most common technology is steam methane reforming (SMR) which uses reaction between hot steam (1000 C) and methane to make CO 2 and H 2. But problems remain as how to store hydrogen in automobiles. Alternative Energy Sources HYDROGEN TECHNOLOGY

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? Hindenburg disaster, 1937 Alternative Energy Sources HYDROGEN TECHNOLOGY

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Energy per gram