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It is no surprise that the world is at a crossroads, where mass energy and material consumption meets global sustainability issues of epic proportions. On August 27, 2009, Arthur Ruoff gave a seminar talk at Cornell University titled “The Declaration of Energy Independence,” which focused on the energy policy of the the United States, and provided insight to how America can become more energy independent and how it can lower energy costs going forward.
Ruoff argues that complete energy independence in America can already be done without any further investment in research. The problems we Americans face today are not technical; they are, instead, bureaucratic and psychological (or, appropriately, political and economical). Energy independence starts with “politics, ecology, economics, population, government, war, money,” and ends with the least important, that is, the actual science and engineering involved in affecting change for the future of energy generation and transmission.
There are bottlenecks down the line in politics, in the way people think, and in cost, and until these bottlenecks are overcome, it is impossible for the already available technology to become widely-built and put into operation.
The importance of this issue is apparent everywhere. Without energy, modern society cannot survive. There would be no trains and cars; there would be no computers and telephones; there would be no refrigerators and microwaves. Today, about 25% of the United States’s energy consumption goes to cars alone, 7% to other means of transportation, 10% to homes and offices, 25% to industry, and the rest to energy production and transmission itself, all totally about 30 billion megawatt-hours annually.
The first law of thermodynamics states that energy cannot be created or destroyed, only converted. So, what feeds this level of energy consumption? The largest source of energy used in the United States is petroleum oil—at around 40% (natural gas and coal are around 25% each). U.S. oil production peaked in the 1970 and has been significantly importing ever since at an exponential and alarming rate. Only in 1980 did U.S. energy consumption begin to appear to level out. But upon further analysis, this temporary dip is attributed to the outsourcing of manufacturing (then importing finished products to market). If we include imports from countries like China, the energy consumption curve of the United States would only continue to rise. In fact, energy consumption is growing much faster than domestic energy production in India and China. It is calculated that within 25 years, India and China will be using the same amount of energy as America is today.
It is a common understanding today that the U.S. energy policy needs to be reformed, for the sake of domestic energy security, if not for the sake of human sustainability on earth. Ruoff proposes the outline of potential solutions (aside from simply consuming less): [1] decrease population, [2] impose a $4 tax on gasoline, and [3] impose a big, exponential tax on heavy non-business vehicles. Specifically, build nuclear power plants domestically and completely eliminate the need of importing oil or gas. How do we pay for this program? It’s simple too. Ruoff proposes that we withdraw all our troops stationed in 761 military bases in 151 foreign countries, thereby saving about $250 billion annually, and all summarized in a simply 3-page proposal.
This seemly uncomplicated approach, however ideal, is impractical. The egregious American mindset is deeply embedded in the people, where bigger is better, faster is better, and more is better. Change comes, unfortunately, slow. Aggregate American disposition certainly does not change on its own. More needs to be done. Finally, we need to bear in mind that this is far from an insular, domestic problem. It is a global one that requires a global effort. As more and more people around the world adopt the American consumerist mentality, we are experiencing an exponentially growing need of energy.
Whichever way we approach this global energy crisis, though, this much is certain: the energy issue will either bring the world’s people together toward a unified effort, or result in its inevitable demise.
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Here on Earth, we hear about the environmental problems that littering can cause. What about littering in space? The problem may not seem very important because, frankly, we don’t spend much time in space (if any) compared to on Earth. Also, space is quite a vast space, for lack of a better word, and it seems very insignificant to have some debris let loose from a spacecraft. However, the “space junk” problem is getting worse as time goes on (debris from several space vehicles does add up), and as long as nobody does anything about it, the problem has the potential to become a major hinderance to space travel and research.
A model of space debris populations around Earth.
What kinds of problems could debris in space cause? They travel at speeds on the order of tens of thousands of miles per hour, which means that debris of any shape, size, and form will be destructive if it collides with a satellite or space shuttle. Collisions with space debris isn’t unheard of. Also, they could delay space launches if it is known that a large cloud of debris is hovering directly over the launch pad.
Space debris comes from a variety of sources. Nuts and bolts could become loose and float away from spacecraft during normal operation. When rocket stages (or segments) separate in space, they release debris. Also, in-space collisions between satellites, while rare, will create large-sized debris – the same goes for intentional spacecraft destruction, such as the Chinese anti-satellite test that was conducted a few years ago. Some of these events unleashes several thousand pieces of debris, most of which are tiny (less than an inch in size) and are much more difficult to track than larger-sized debris.
Over the past few decades, scientists and engineers have brainstormed possible solutions to decreasing space litter. However, all of the ideas have been technologically and/or economically infeasible. This could change as time goes on, especially as technology advances and/or the cost of launching a vehicle into space decreases. One possible solution is launching a garbage-collecting spacecraft to do just that, but what to do with the collected garbage is a problem. Another solution is somehow colliding objects with the orbiting debris in an effort to reduce their energy enough so that they fall into the Earth’s atmosphere (due to gravity) and burn up, but no one has thought of a feasible means to do that.
(Image from Wikipedia)
One of the most revolutionary kitchen tools we have today was accidentally discovered and then invented in the 1940s and ’50s. The microwave oven, whose origins has nothing to do with cooking, dates back to World War II. According to IdeaFinder.com:
During World War II, two scientists invented the magnetron, a tube that produces microwaves. Installing magnetrons in Britain’s radar system, the microwaves were able to spot Nazi warplanes on their way to bomb the British Isles…. The idea of using microwave energy to cook food was accidentally discovered by Percy LeBaron Spencer of the Raytheon Company when he found that radar waves had melted a candy bar in his pocket. Experiments showed that microwave heating could raise the internal temperature of many foods far more rapidly than a conventional oven.
So, what exactly is a microwave, and are microwave ovens safe? We’ll need to consider the electromagnetic spectrum, something you’ve probably seen in your high school physics and chemistry classes.
The Electromagnetic Spectrum
Put simply, a “micro”-wave is a “small” wave that is on the order of 1 centimeter, not on the order of 1 micrometer, as the name would suggest. That is, these waves have wavelengths of about 1 centimeter. (A centimeter, or cm, is 1E-2 m.) When we compare this with visible light, which is on the order between 1E-6 and 1E-7, we see that microwaves are longer than visible light. If we remember that speed of light = (frequency of the wave)*(wavelength of the wave), where the speed of light is about 2.9979E8 m/s, then we can see that frequency is inversely proportional to the wavelength. What this means is microwaves travel at a lower frequency than visible light. (Frequency is measured in cycles per second, or Hertz.)
Again, from IdeaFinder.com:
[Microwaves] are found in the non-ionizing portion of the energy spectrum, between radio waves and visible light. “Non-ionizing” means that microwaves do not detach charged particles and produce atoms with an unbalanced plus or minus charge. Microwaves can therefore safely produce heat and not cause food to become radioactive.
Now, let’s take a look at a few practical things about microwave ovens, like why radiation doesn’t escape into the kitchen, or is it safe to stop the microwave and reach in to grab the piping hot HotPocket about eat it right away? If you notice that there is a metal mesh screen in the door of the microwave. The side of the holes, on the order of half a centimeter or so, allows the physically smaller visible light waves to pass through but prevents the “larger” microwaves from leaving the microwave oven (remember that light waves are orders of magnitude smaller than microwaves). Also, you don’t need to worry about residual microwave radiation from the microwave oven because these waves always travel at the speed of light and will have been absorbed into your food long before it gets a chance to escape and hit you in the face.
More information on the history of the microwave oven can be found at Gallawa.com. Image from ScienceProg.