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A Japanese researcher got curious about the electromagnetic radiation caused by cell phone users inside commuter train cars, and has calculated that it could exceed safe exposure guidelines. Interesting theory, but I'd like to see it backed up with some actual field strength measurements. It may actualy vary quite a bit from moment to moment, since a cell phone adjusts its power output based on signal strength. http://www.newscientist.com/news/news.jsp?id=ns99992238
38 responses total.
Based on *received* signal strength? Then it would boost its power up to high in a metal train car, which partially shields the phone from the tower. It would also not be as simple as the article tends to make it, as there would be radio "hot" and "cold" spots in the car.
Not necessarily. I get higher signal strength inside my metal car than I do in the middle of the concrete office building I work in.
Concrete buildings are reinforced with steel rods/mesh. Pretty good Faraday shield. But my statement in #1 applies to #2 as it depends where you are in both a car or a building.
re#3: Its called 'rebar'.
If you want to play contractor....
Its called 'rebar' in the Home Depot insert in the newspaper - hardly targeted towards contractors.
Larson used the word "rebar" in a Far Side cartoon. (Two cavemen standing next to a smoldering chicken-wire frame of a cave, one saying: "Boy, you wiped out, Kumba...Nothing left but rebar.")
It started as a contractor term, adopted by everyone as it sounds sexy. A lot of words come into our vocabulary that way. People like to swing the lingo as it makes them (they think) sound knowledgeable. Ask them to describe the types and uses of the many varieties of "rebar" and they will be struck dumb. Take a look at what it's called on a professional site (http://www.asf-rebar.com/charts_specs.htm): "ASTM Standard Reinforcing Bars".
If the purpose of communication is to be understood, using the commonly understood terminology is helpful. If somebody says rebar maybe it sounds sexy to you, but to most of us it sounds like metal bars used to reinforce concrete. If somebody starts talking about ASTM Standard Reinforcing Bars, chances are the average listener won't have a clue what they're talking about.
#8> Just because a word starts out as professional lingo doesn't mean it needs to stay that way forever and always. ,
Speaking of which, I got to wondering something yesterday. Those swivel joints on the drive axles of front-wheel-drive cars....why are they called "constant velocity joints"? What's constant about their velocity?
They the drive and driven shafts turn at the same velocity (rpm), independent of the angle between them (within allowable limits).
They used to call them "Universal Joints".
One still should get it right, then. I referred to "reinforced with steel rods/mesh". Welded wire mesh is not "rebar", and those in the industry know that "rerod" is equibalent to "rebar". So what I said was correct but avoids "jargon". (I've been wondering why I care... 8^} I think it was because #4 was an ignorant attempt at correction. Oh well.... who cares anyway? It still forms an electromagnetic shield in concrete buildings.)
Re #13: a universal joint is NOT a constant velocity joint. See, for example, http://www.4wdonline.com/A.hints/Universal.html.
Ah - so they're slightly more complicated are they? Interesting...
It was a little harder finding a diagram of a CV joint. There is a rather poor one at http://www.hewett.norfolk.sch.uk/curric/techweb/epscweb/mech1.htm#coupling The limit would be using a piece of hose as a flexible coupling, but that is not a very rigid coupling, which is needed for power and force transmission.
Ah, okay, that site clears it up. I hadn't realized that a universal joint's speed varied through its rotation when it was at an angle. Universal joints sure are more durable than CVs, though. I found a torn CV boot on my car recently and my mechanic told me I might as well get the whole driveaxle replaced, because once the boot is torn the CV is usually damaged almost immediately from the grease being contaminated. Universal joints on rear wheel drive cars seem to last the life of the vehicle with no grease boots at all.
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"Old World", "New World", "Third World". "First World" is a back-formation from "Third World", so there is NO "Second World".
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I don't have handy the references, but it's my understanding that #21 is mostly wrong. In particular, Switzerland would not be considered third world.
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#24> Heh.
Hmmm. The term "third world" was first used by the French writer Alfred Sauvy in 1952. He compared the third world of non-industrialized, mostly poor countries to the third estate of the peasantry in pre-revolution France, and implied that more industrialized nations were comparable to the first and second estates.
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Um, no. The book _Le Tiers-Monde_, inspired by earlier writings by
Sauvy (who was a demographer), was published in 1956. A periodical with
same title begin publication in 1959. In fact, Sauvy first used the
term "third world" ("tiers-monde," because it was in French) in an
article titled "Trois mondes, Une plančte" in the August, 1952 issue of
"L' Observateur." The magazine was a socialist rag, and the article had
more to do with which side in the Cold War would dominate the
underdeveloped countries of the third world. It made no mention of
third world countries simply being non-aligned ones, since the analogy
was being drawn between underdeveloped nations and 18th-century French
peasants.
Right. It was a post-colonial thing, the idea being that all these new nations in Africa, South America, and Asia that had, until the middle of the 20th century, been dominated by European nations, but now had their independence and were going to form new, enlightened governments based on modern political theories.
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Actually, when I last looked this up, the earliest reference I could find was a meeting in 1945 or so. It's been a decade or more since I cared enough to research it, though. And I realised even then that some folks just don't care to be told that they are wrong. No matter how wrong they are.
you might be wrong about that, Joe. ;)
Re: rebar, universal joints, third world: Is everyone trying to prove that they are smarter than everyone else, or just that they are better at looking stuff up?
Do people ask questions about how others discuss stuff to show that they are above such exchanges of trivial informaation?
yes
#34: Sure, the same way they ask questions to show that they are above such exchanges of trivial theology.
Actually, when I do look a fact up, I usually do try to phrase my response to say so. But that's because I have a lousy memory and I've long since given up trying to impress people with my breadth of factual knowledge.
#36 is a bit more mean-spirited than is really appropriate. I apologize.
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