Planetary Orbits

From the Astronomy Department at the University of Nebraska-Lincoln:

This is Why You Pay Attention in Science Classes

According to a national survey, commissioned by the California Academy of Sciences:

• Only 53% of adults know how long it takes for the Earth to revolve around the Sun
• Only 59% of adults know whether or not the earliest humans and dinosaurs lived at the same time
• Only 47% of adults can roughly approximate the percent of the Earth's surface that is covered with water
• Only 21% of adults answered all three questions correctly

Another Year, Another Call for Water Rationing in California...

Even though it's been rainy on and off for the past month or so, I keep seeing articles in the news, like this one from the New York Times, about the drought that California is going through. Apparently, rain has been hitting the Bay Area but not really much else... for three years running. The Times article talks a lot about the impact of the drought on farming communities in the Central Valley (less rain = fewer crops = fewer jobs) and the intensification of hardships that out-of-work farmers face because of the Financial Crisis.

Along with the drought comes the annual call from the governor's office to ration water. Just two weeks ago:

The governor called for a statewide water conservation campaign and asked all urban water users to immediately reduce their individual water use by 20 percent.

After I read about the call for water rationing, I started wondering to myself,

How much of a difference does 20% of my personal water usage make?

• From the U.S. Geological Survey: In 2000, the U.S. used 408 billion gallons of water in total per day
• 43 billion gallons per day were used for the "Public Supply" (that's like plumbing and water fountains)
• From the Environmental Protection Agency: About half of the Public Supply goes to residences, people's homes (the other half goes to office buildings, schools, etc)
• That means that about 21.5B gallons per day were used residentially in 2000 (ie 1/2 of 43B gallons)
• 21.5 billion gallons (Residential) ÷ 408 billion gallons (Total) = 0.0526 = ~5%
• Residential water use in the U.S. accounts for about 5% of total water usage

Just 5% of total water usage is in people's homes, and yet the governor is asking us to tighten our belts. Don't get me wrong, we should be trying to minimize our personal water consumption all the time, not just during droughts. However, since residential consumption is such a small part of the total, if we all reduced our personal (ie residential) consumption by 20%, that would still only mean a 1% reduction over all for total water usage.

• 20% (reduction in residential usage) of 5% (residential usage as percent of total usage)
• 20% of 5% = .20 x .05 = .01 = 1%

This all is just to demonstrate that residential water consumption is just a drop in the bucket, so to speak. Reducing water usage is a good habit to have, however the real water usage is clearly elsewhere.


CA is by far the largest water-consuming state, dwarfing even TX, the second largest
Where is all the water going?
There two major uses of water: agriculture and electricity. It makes sense that a lot of water would go to farming; crops need clearly need it. Indeed, Governor Schwarzenegger is asking us to reduce our personal water consumption, so that more water can be directed towards irrigation. The present drought means that the sky isn't providing the water crops need in the form of rain. The other major use of water is the less obvious one: electricity. The majority of electricity in the U.S. is produced in Fossil Fuel burning power plants. These plants burn coal or oil to produce a great amount of heat, which is used to boil water. The steam from the water spins a turbine, which as it rotates creates electricity.

• As was stated earlier, 408B gallons are consumed per day
• 137B gallons go to Irrigation
• 137B ÷ 408B = .3357 = ~34%
• 196B gallons go to Power Plants
196B ÷ 408B = .4803 = ~48%
• So, Irrigation accounts for 34% of the Total U.S. water consumption, whereas Electricity accounts for 48%

If we really are serious about cutting down the amount of water that is consumed, not just in California but in the whole U.S., we need to consider more than just residential use. Cutting residential use by 20% could save up to 4 billion gallons of water per day: that's a HUGE amount of water we are just flushing away!

However, to really save water, we need to move away from Fossil Fuel burning Power Plants. Not only do they account for almost half of U.S. water consumption, but they produce Green House Gases that contribute to Global Warming. There are alternative modes of electricity production that use significantly less water and produce no Green House Gases. While we're at it, we should reconsider our farming practices which create a great deal of Green House Gases as well. Now is the time to really examine how we, as a state and country, use our resources and impact the environment.

[Note: For the most complete breakdown of U.S. water consumption by state and end-use, check out this chart from the U.S. Geological Survey. It provides a much more complex picture for changing our state and national priorities.]

Internet Resources on the Housing/Finanacial Crisis: III

This is a really nifty video that explains how the Financial Crisis happened (and is still happening) in the US. It's got all the info you need to understand what's happening in the news -- just don't get intimidated by the big words (all of them get explained eventually).


The video above is about 11 minutes long and explains what happened in broad terms. It give the essential background of the Crisis.

On the other hand, if you would like a detailed account of the specific decisions made and actions taken by both the Wall Street banks and the US Government as the crisis unfolded over the Summer and Fall of last year (to try to stop the banks from failing), then check out this (hour long) video. It's an episode of Frontline, called (menacingly) "Inside the Meltdown."

Also, I've been posting links to the episodes of the radio show This American Life that similarly explain the Financial Crisis in ways that people can actually understand. Well, they just aired a new one about what the US Government is trying to do right now to save our sinking economy (and why it's so hard to figure out what to do). It's called, Bad Bank.