Week of September 22nd

A few notes on this week:
Movies
I think the science movies are a really fun idea. I am a fan of anything inbetween a documentary and an disney movie and I am really interested in seeing an inconvenient truth and the 30 days episode. I like how they wouldn't always be mandatory also, between 6 and 8 on thursdays is really prime school activities time and its a hard block of time to get available every week. Most clubs meet between 6 and 8 on tuesdays and thursdays and the honors night classes make it harder to get involved. Its nice to have some weeks when time is easier to balance.
Lab
The CO2 lab was interesting, the equipment didnt really work for my group though. We got weird readings that didnt really make sense, like the least amount of CO2 being in starbucks, that can't be right. I like the application questions though, about finding out how long people could survive in an enclosed space before it becomes too difficult to breathe, its something I have always wondered about strangely enough. The lab was much simpler and better organized than last week, it makes me wonder why we started with such a complex lab with so many difficult applciation questions, this one, I think, would have been a better choice for the first class.

*sorry for the shorter entry, my group presented on Friday so there isn't much to respond to there, although the questions by the class were very interesting, I gues thats the perks of an honors class. I really liked the brief review of chemistry in preparation for the next lab. Everything came right back to me once it went on the board and I feel really prepared to do the lab now.

Chapter 3: Energy: A closer look

6. The United States imports about 12 million barrels of oil per day



a) consult the tables in this chapter to convert this quantity to an equilivant power, measured in watts.

barrels of oil= 12,000,000
conversion number= 6.12 GJ per barrel of oil
12,000,000(6.12)= 7.344x 10^7 GJ= 7.344x 10^16 J
W=J/s
1 day=86,400 s
(7.344 x 10^16J)/(86,400s)=8.5 x 10^11 W



b)Suppose we wanted to replace all that imported oil with energy produced by fission from domestic uranium. How many 1,000-MW nuclear power plants would we have to build?

1,000MW= 10^9 W

(8.5 x 10^11W)/(10^9W)= 850 nuclear power plants



7. Assuming that 1 gallon of crude oil yields roughly 1 gallon of gasoline, estimate the decrease in daily oil imports that we could achieve if the average fuel efficiengy of US cars and light truck, now around 21 mpg were raised to 50 mpg typical of a modern hybrid car. Assume that average vehicle is driven 10,000 miles a year and that there are about 200 million cars adn light trucks opperating in the United States.



(12,000,000 barrels of oil)(42 gallons per barrel)= 504,000,000 gallons of oil now
10,000mpy/365days=27.397 mpd
(200,000,000 cars)(27.397mpd)=54.794x10^9 miles driven in US a day
54.794x 10^8m/50mpg=1.09588 x 10^8 gallons a day
54.794x10^8m/21mpg=2.7397x10^8 gallons a day
2.7397x10^8-1.09588x10^8= 1.64382x10^8gallons a day
1.64382x10^8/42 gallons per barrel=3.9 million barrels saved a day or about 1/3 the daily US import of oil


This problem goes to prove that if every American bought a hybrid car, as has already happened in Europe, we could decrease our daily oil imports by 1/3! I am surprised that the government, which is so intent on becoming independent of foreign oil has not pushed the price reduction of hybrid cars. I don't feel that the average American really believes that hybrid cars could be as economical as this problem suggests, it seems that we already have the solution to many of our energy problems but we don’t utilize it. I wonder if the government is keeping the hybrid car solution from becoming affordable for the average American because of its ties to the oil industry, it makes me wonder, when we have the solution staring us in the face, why we cant fund hybrid car production.

Plenary Session: GW Sustainability

I thought the plenary session on the steps that are being taken at GW to work towards sustainability was very interesting although at some points basic. I was not aware of the intense support President Napp has for the progress of environmental research and it certainly makes me proud as a GW student to be a part of an school that supports such a innovation. I also liked hearing about some of the things GW has already done to become more environmentally friendly. For example I did not know that the new dorms being built would be certified by LEED or that we were working to be carbon neutral, which is a process I really support although it is somewhat intangible. I live in Potomac House and I never thought about how much money the light sensors in my hall save before last night. I also like that the sustainability task force is not only working on renovating buildings but also the curriculum so that students can get funding to do research on environmental issues through the center of sustainability. I believe that a very good point was made when the male speaker said that the future economy will be dependent on experts in environmental issues and sustainabiliy. If we could find a way to make saving the environment profitable we could do so much good in the world and enact so much change!

Finally, I really enjoyed the "costs of driving a car" brainstorm. I am studying economics and we have discussed the opportunity cost of driving a car (the money you spend on driving you cant spend on other things,) but I have never thought of all of the other costs of driving such as time and health risks.

I am definitely thinking about attending the symposium on October 6th about urban sustainability...maybe we can go as a class.

Week of September 8th

Week of September 8th

1. Define force, energy and power; units of measure

• Force- whatever can cause an object with mass to accelerate. Measured in Newtons.
• Energy- a scalar physical quantity that is a property of objects and systems which is conserved by nature. The ability to do work. Measured in Joules.
• Power- the rate at which energy is transformed from one form to another or transferred from one object to another. Measured in watts or joules.
  

2. Why is Co2 a greenhouse gas and nitrogen not?

CO2 absorbs and traps heat in the earth’s atmosphere and nitrogen does not.

3. My question (number 3)

Solar Energy is incident at the top of the Earth’s atmosphere at the rate of about 1368 watts per square meter. This energy effectively falls on the cross sectional area of the planet. Calculate the total rate at which solar energy arrives at Earth.

Find cross sectional area of the planet. A=(3.14)r^2
R= 6.37 x 10^6 m
A= 1.274760 x 10^14 m
Multiply cross sectional area times rate
(1368 W/m2)(1.274760 x 10^14)= 1.743 x 10^17

How does this compare with energy flux at the earth’s surface?
31% of sunlight gets reflected back into the atmosphere.
69% of sunlight actually reaches the earth’s surface.
45% is converted right into solar energy
23% is evaporated
1% goes into the energy of winds and currents
0.o8% is used for photosynthesis.
Therefore if you multiply the number above by .69 you get the actual amount of solar energy that hits the earth’s surface. (1.202 x 10^17) This number is considerably smaller than the actual amount of solar energy that hits the top of the atmosphere.

What factors affect this quantity?
Most of the solar energy is reflected back into the atmosphere via clouds and reflective particles in the atmosphere, but ice, snow, deserts and other surface features can have the same effect.

I really enjoyed what we did this week in class. Because everyone is an honors student the issues are given life by the presenters and their opinions. I think the lesson could only have been made better if we had been given a little background information before hand; I haven’t take physics since the 11th grade and I don’t really remember how all the formulas work as simple as they may be. Maybe a review sheet would help.

Research

I found most of my information from www.epa.gov, or the website for the environmental protection agency of the federal government. I found the site both comprehensive and credible and I think it will be a good resource in the future.

Sustainability
"meeting the needs of the present without compromising the ability of future generations to meet their own needs" This is the definition adopted by the UN.

"This concept of sustainability encompasses ideas, aspirations and values that continue to inspire public and private organizations to become better stewards of the environment and that promote positive economic growth and social objectives. The principles of sustainability can stimulate technological innovation, advance competitiveness, and improve our quality of life."


So basically sustainability is reducing our affect on the planet and trying to meet our daily needs in ways that do not leave a lasting negative impact on the environment.

The term "green"

From my research I found that the term "going green" and sustainability are basically inter-changeable.

Things we can do to "go green:"
promote scientific research
use more advanced technology
reduce-reuse-recycle
be efficient with water
increase energy efficiency in your household
preform an enery audit
purchase energy star products
purchase green electricity, carbpn offsets and/or generate your own energy
include more vegetable protein in your diet (makes best use of limited land resources)
enjoy local food (reduce tranportation of food)
teach the youth about energy issues
make it profitable to provide clean energy
use proper insulation
make cars more energy efficient
elect passionate leaders ready to make change

Climate Change

climate change is “any significant change in measures of climate lasting for an extended period of time.”

Global warming is the increase in temperature in the earths atmosphere

the climate has always been changing- prior ice ages

3 main changes in last 2,000 years= medieval climate anomaly (between 900-1300 AD Europe, Greenland and Asia have slight temperature increase,) little ice age (1500-1850,) and the industrial era (1900-now= relative warmth.)

the climate has also been changing at different rates: the climate usually has periods of stability and then rapid change (rapid change is when we change from an ice age to a period like now) "Interglacial climates tend to be more stable than cooler glacial climates

many different things cause climate change namely natural factors, natural processes and human activities.

causes of climate change prior to 1780 include: changes in the Earths orbit (affects amount of sunlight that hits earths surface,) change in the suns intensity,changes in ocean currents and volcanic eruptions (cause aerosol and co2 emissions.)

causes today include the use of fossil fuels. Using fossil fuels result in the green house effect in that they trap heat in the atmosphere.

Also “a change in land use and cover can affect temperature by changing how much solar radiation the land reflects and absorbs.” Land use has change recently due to deforestation, reforestation and urbanization.

The big issue: the global average temperature in the last few years has most likely been higher than the global average temperature in the past 400 years. In fact, “the Earth’s everage surface temperature has increased by about 1.2 to 1.4 degrees F in the last 100 years. This increase in temperature can also result in a change in precipitation, storms and sea level. This climate change results in “rising sea levels, shrinking glaciers, changes in the range and distribution of plants and animals” and many other issues

What is the U.S. doing about it? “A) slowing the growth of emissions B) Strengthening science, technology and institutions C) enhancing international cooperation.

Alternate Forms of Energy
Wind power- could provide 1/3 our or electricity needs
Solar thermal power- a small region of this power could fulfill all of the U.S.’s electricity needs
Solar photovoltaics- could provide ¼ of our electricity needs
Geothermal power- electricity from underground hot rocks

The Energy Theory
Momentum is always conserved
Sum of kinetic, potential and heat energy always conserved
Measured in Joules (1 watt per second)
Kinetic energy- energy of motion
Potential energy- stored energy
Heat- energy that is flowing as a result of temperature difference