Monday, April 6, 2009
Jet airplanes are a normal part of today's society. The military uses them, we fly from place to place in them, there are giant industries that build them, and words and phrases based on the use of jets has found its way into mainstream language - jet lag, for example. Lift the veil and look deeper, though, and you will find the world of jets is a strange, strange place.
Jets work by reaction propulsion. This is the use of expanding gases to create thrust. The first known reaction engine was invented in 150BC by Hero of Alexandria. He called it an Aeolipile. By heating water up in a ball with two opposing bent tubes attached; steam exiting through the tubes creating a reaction force that spun the ball. It was a novelty. No one could think of a use for it.
In the the 18th century Western world, Sir Isaac Newton was the first to theorize that a rearward-channeled explosion could propel a machine forward at a great rate of speed. The first practical uses involved steam. Steam was used to power carriages, mill wheels. and other locomotion devices.
Things got a bit more interesting when various inventors tried to create flying machines propelled by reaction engines. Henri Giffard built an airship which was powered by the first aircraft engine, a three horsepower steam engine. It was very heavy, too heavy to fly. In 1894, American Hiram Maxim tried to power his triple biplane with two coal fired steam engines. It only flew for a few seconds.
American Samuel Langley made model airplanes that were powered by steam engines. In 1896, he was successful in flying an unmanned airplane with a steam-powered engine, called the Aerodrome. It flew about 1 mile before it ran out of steam. He then tried to build a full sized plane, the Aerodrome A, with a gas powered engine. It crashed immediately after being launched from a house boat.
The first patent for using a gas turbine to power an aircraft was filed in 1921 by Frenchman Maxime Guillaume. In the U.S. a few other patent applications followed but Edgar Buckingham of the US National Bureau of Standard published a report saying,"there does not appear to be, at present, any prospect whatever that jet propulsion of the sort here considered will ever be of practical value, even for military purposes."
Dr. Hans von Ohain and Sir Frank Whittle are both recognized as being the co-inventors of the turbojet engine. They didn't know of each other and worked independently on the idea. Whittle could not get institutional funding to work on his idea and had to find private money. Von Ohain was a student and did his work through his university. They both got patents around 1930. Hans von Ohain's jet was the first to fly in 1939. Frank Whittle's jet first flew in in 1941. More info on the history and types of jet engines.
Many major jumps in technological innovation have followed the same pattern: Someone invents a new thing but no one can think of a use for it. Officialdom declares the invention useless or impractical. Inventors privately fund their research and, hopefully, after a period of time, the idea catches on and practical applications are invented.
Once the turbojet engine was invented, enthusiasts pushed the limits. One fun thing to do is to see how fast you can go using a turbojet for power. Officially, the fastest manned, air-breathing jet vehicle is the SR71 Blackbird - about 2,200 mph - a little over three times the speed of sound. In 2004, NASA tested a scramjet (this engine can only operate at speeds faster than sound). It hit nearly 7000 mph or Mach 9.6.
In the world of land speed records, Richard Noble's Thrust SSC set the current world record in 1997 in the Black Rock Desert of Nevada (the same location that the Burning Man Festival is held. The Thrust SSC went 763 mph - faster than sound! It was powered by two afterburning Rolls-Royce turbofan engines developing a thrust of 50,000 lbs. The fuel consumption was about 0.04 mpg. Here's a video.
Some hobbyists spend their free time building jet engines in their garage. One way to do it involves using an automotive turbocharger as the main component. They create engines that make a lot of noise but don't really produce much thrust. Those with more money buy used military and commercial jet engines and mess with them. These hobbyists are itching to attach jet engines to something to see if they can make it go really fast. People have put jet engines in Volkswagens, trucks, go-karts, wheelchairs, bicycles, lawnmowers, beer coolers, and even an outhouse!
At serious government and industrial test locations, scientists and engineers get paid to test jet engines. What fun! Some of the things they do, to make sure the engine can handle whatever it may encounter, is to shoot various things at high speed into the running engine. For example, in testing the GE90-115B Jet engine (the largest jet engine in production) they shot 4.5 tons of water per minute and 3/4 ton of artificial hail into the fan. See a video of this engine being tested.
Birds getting sucked into jet engines is a serious issue. This is what caused a commercial jet to crash land in the Hudson River a month or two ago. Because of this potential danger, engines are subjected to the "chicken ingestion test." Since 1972 they have been using a compressed-air powered chicken cannon (also known as a rooster booster) to shoot chicken carcasses at 180 mph into the engine while it is running at full speed. Not too long ago many testing facilities bowed to pressure from animal rights organizations and switched to fake birds made of clay and plastic. Some urban legends have developed around the chicken cannon. Find out about chicken cannon legends.
In both the history and current use of jet engines we see the activities of people who have gone off the map of mainstream. They go out beyond the edge, find new things, and bring them back as gifts to society. Jets are just one example.
Tuesday, February 10, 2009
Banks are businesses. They exist to serve a need or desire in the marketplace and to profit from meeting those needs and desires. Banks make money primarily by collecting interest on the money they lend. Therefore, banks have to lend in order to make money. If they don't lend, they go out of business. They can also go out of business if they lend to people who don't pay the money back.
Banks have been damaged lately by the collapse of the housing market. Value has disappeared practically overnight. People have been defaulting on their loans and the capital that banks usually have available to lend has dried up. They are gun-shy. They got caught with their pants down and are extremely reticent to take risks. This is why they aren't lending like they used to. Once they get a handle on things, credit should loosen a bit. But it's not all the fault of the banks.
Just because a lender is willing to lend you money doesn't mean that you have to take the loan. If you have any doubts about your ability to pay it back, then you shouldn't take it. You don't have to borrow money at all. Really! It is quite possible to exist without borrowing money. This whole easy-credit thing is a relatively new development that got of control over the last 30 years. It used to be the norm that credit was hard to get.
During this anomalous rise of easy credit, savings rates in the U.S. have dropped to near zero while personal debt has risen to record levels. Instead of using savings in case of an emergency, people use credit cards. This is a crazy way to manage personal finance. It's expensive, too. If you saved up money for a rainy day, you could earn interest on it until you needed it. Instead, by using credit cards, you end up paying interest (at a much higher rate). In addition, using credit cards means that you need to continue to earn more money and have fewer emergencies in the future. There are no guarantees of either of those things happening.
We are way out on the limb of credit and the further out we go, the more likely the limb will break and we will fall hard. The slightest little glitch in the economy can crash the whole thing. That's what's happening now. The limb we are hanging on is cracking. The government and practically everyone are trying their best to get credit freed up so we can keep borrowing and consuming. This is not the solution. It's dangerous. We are trying to patch the crack in the limb so we can go further out on it. The fall will be even harder if we pursue this course.
What i am trying to say here is that the major problem with the economy is not the bankers, the government, the housing market, or other economic challenges we face. It's credit. The best thing that we can do is to live within our means, stop borrowing and start saving. Just ask your grandmother.
Wednesday, February 4, 2009
The IRS Tax Code is so long and convoluted that I can’t even find agreement online on how many pages it is. The official count is somewhere over 13,600 pages! With that kind of extreme complexity, it’s no wonder people screw up when doing their taxes. It would also not be a surprise to find that millions of people cheat on taxes either by not understanding the laws, or by purposefully misunderstanding parts of the law to their own financial advantage. I suspect that even the IRS agents don’t understand all of their own code, especially since parts of it change every month.
I’m about to do my annual tax return. My tax situation is a little complicated but nowhere near as complicated as Tom Daschle’s is. I would have never thought that having a friend provide limo service for free, would result in a $130,000 tax. This is why millions of dollars are spent each year to hire tax accountants to figure out our taxes for us. Interpreting the tax laws is a huge industry. I think it’s ridiculous. We need a much simpler tax code. It should be easy for any person to do their own taxes.
Unless the U.S. Senate, who approves cabinet nominees, can prove that candidates purposefully cheated, I don’t see why it should be a big issue if the candidate messed up by accident.