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D H

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Everything posted by D H

  1. There's this too. Newsweek recorded the results for evangelical Protestants, non-evangelical Protestants, Catholics, and agnostics/atheists. Fully 73% of evangelical Protestants chose the "created in present form" option, while only 39% of non-evangelical Protestants and 41% of Catholics followed suit. Oddly, 13% of the agnostics/atheists who responded chose the "created in present form" option and 27% chose the "God guided process" option. I added the emphasis to that last sentence. 40% of atheists/agnostics think god created humans in their present form or guided the evolutionary process??? Something is deeply wrong with this polling on creationism versus evolution.
  2. Hawking's Theory of Everything is an unauthorized book. From Hawking's website: http://www.hawking.org.uk/info/iindex.html It has come to our attention that the book "The Theory of Everything: The Origin and Fate of the Universe" has been published. Professor Hawking would like to make it clear that he has not endorsed this book. The text was written by him many years ago, however the material has already been published in books such as 'A Brief History of Time'. A complaint was made to the Federal Trade Commission in the US in the hope that they would prevent the publication. We would urge you not to purchase this book in the belief that Professor Hawking was involved in its creation. Nowhere does Hawking claim to have developed a theory of everything. His popular books describe what the ongoing search for a GUT is all about.
  3. No, it does not. Name one study that shows drinking water does not cause cancer. No one would fund such a study, for one thing. The study would be inconclusive, for another.
  4. Ahem. Ex-smoker. Most ex-smokers are among the worst anti-smokers. Not me. The habit stinks, costs lives, costs money, and ruins clothes. So I quit. That was my decision. It is not my business and it is hypocritical for me to tell people to stop smoking for their own good. One theme I have seen throughout this thread by the more vehement anti-smokers is one of selfishness. The selfish ones are the anti-smokers who tell people to stop smoking for their own good (the non-smokers' good, that is, not the smokers'). Look very hard in the mirror. Stop lying to yourselves, and more importantly, stop lying to everyone else. The stats on long-term second-hand smoke are extremely dubious. The stats on short-term second-hand smoke exposure are outright lies.
  5. I said it was ludicrous that the threshold should be zero risk. Why pick on smoking, when practically every human action has some risk of causing harm to others? As far as the harm from short-term exposure to second hand smoke, nearly every study that proves any substantial harm from extended exposure to second hand smoke has been debunked. This is absurd. The burden of proof is on those who want to prove the association, not the other way around.
  6. This is ludricrous. My driving is a potentially deadly activity to me and to others. The only way there is a zero chance of me not passing this deadly risk on to other people is to forbid me to drive. One reason why this came to pass is the reasoning that underlies the initial paragraph of your post. This "zero risk" attitude has come to pervade American thought. Our society is much, much worse off for this "zero risk" attitude. Shakespeare outlined the solution in Henry VI (Part 2), Act IV, Scene II.
  7. What rights? I do not see anything in the constitution regarding smoking. What about the right of a someone who wants to build a restaurant/nightclub/whatever where smoking is allowed? What gives you nosy, repressive, obnoxious, lieing antismokers the right to walk over that person's rights?
  8. This is more of the same. The "science" on second-hand smoke has been ridiculous for a long time. For "scientists" to say that second-hand smoke is more harmful than direct smoke is just ludicrous (and yes, I heard some so-called scientists say just that.) For scientists to say that 20-30 minutes of exposure to second hand smoke will result in any meaningful increase in the likelihood of a heart attack is just ludicrous. All that this kind of garbage does is give true science a bad name.
  9. Another article: http://biology.plosjournals.org/archive/1545-7885/4/4/pdf/10.1371_journal.pbio.0040091-S.pdf The predecessors of cats and humans split when dinosaurs still roamed the Earth.
  10. He can hold the center of rotation fixed by make R2 a function of the second objects mass, R2 = M1R1/M2. With M1=1, and R1=1, R2 = 1/M2.
  11. The problem with your analysis starts here. Your analysis assumes circular orbits. The quoted text is not valid. The circular orbit velocity is a function of the masses and the distance between the masses. When you change M2 (and R2), you also change V1.
  12. You are confused, but then again, that left and right stuff is a bit confusing. The skewness itself is just a number, so the terms positive and negative skewness are straightforward. One way to remember the left/right stuff is that it corresponds with the orientation of the numberline. Since negative numbers are to the left of zero, negative skewness is the same as left-skewed. The same goes for positive skewness and right-skewed. The first thing to remember is that skewness is measured with respect to the mean. The mean divides the PDF into two equal partitions: [math]\int_{-\infty}^{\infty}(x-\mu) f(x)\,dx=0[/math] This is the first of a family of moments [math]u_i[/math] about the mean. The skewness is just the ratio [math]u_3/u_2^{3/2}[/math]. The third moment and the skewness share the same sign since the second moment is always positive. Think of what that means when one tail is "longer" than the other. The weight [math](x-\mu)^3[/math] will have more impact on the long tail. The skewness will be positive if the long tail is on the right (positive) side of the mean, and negative if the long tail is on the left side of the mean. The left/right nomenclature thus refers to which side has the longer tail. Some distributions with long tails include salaries (people don't get negative salaries, but the sky is the limit for CEOs) and distances (non-zero by definition, but points can be very far removed from the origin). Distributions of salaries and distance are skewed to the right. Part of the reason you are confused is that the median of a distribution usually lies on the opposite side of the long tail. For example, consider househole income, which is skewed to the right. Over half the households made less than $44,000/year in 2004. Because the sky is the limit with respect to salaries, the mean household income was considerably higher: over $60,000/year.
  13. The two largest professional organizations involved with computing technologies, the ACM and the IEEE, jointly developed recommended curricula for computer science, software engineering, computer engineering, and information technology. You can find these curricula at this site: http://www.acm.org/education/curricula.html. Looking at these curricula might help you decide whichway you want to go. There is not very much overlap between the curricula. These fields have become quite distinct domains of study.
  14. Computer science is concerned with the fundamentals of computing. Software engineering is concerned with applying the techniques developed under the guise of computer science to real-world problems, particular to BIG problems. This is a bit overbroad. The two topics overlap considerably. Many colleges don't have software engineering departments, instead placing software engineering as a subtopic of computer science. The basics for computer science and software engineering are very similar. If you go to a school that offers both degrees, you could easily switch from one to another up until you junior year.
  15. There is an international law prohibiting nations from claiming the Moon (or some other celestial body). It is the "Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies", aka "The Moon Treaty". The US is a signatory nation. Some excerpts: Article I The exploration and use of outer space, including the Moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all mankind. Outer space, including the Moon and other celestial bodies, shall be free for exploration and use by all States without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies. Article II Outer space, including the Moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means. The treaty, in full, is at http://www.unoosa.org/pdf/publications/STSPACE11E.pdf
  16. D H

    scheme

    "Let" pairs the arguments and their values, making it obvious what the value of each argument is. "Let" is equivalent to a lambda expression in which the argument values are separated from the arguments. This is a prototypical example of "syntactic sugar". "Let" does not add any functionality to Scheme but does makes the existing functionality more understandable.
  17. The downside is that France (and other European) have a significantly higher unemployment rate than in the US, where a job is not a "right". Paradoxically, treating a job as a right means more people don't have that right than in those places where having a job is treated as a privilege. Were I an employer, I would very careful in my hiring practices if I knew it would take Herculean efforts to get rid of a loser.
  18. The kitchen and bathrooms in our house needs improvement. 25 year old wallpaper, etc. If I took out a home improvement loan I would be impacting the negative savings rate. I have three kids in college (ouch!). This is not cheap. We are now spending the money we intentionally built up over the years to put our kids through college. Negative saving rate! I still manage to put money into a 401K, with matching funds. How much of this counts as positive savings? (From what I can tell, it doesn't. Then again, I am just a dumb engineer, not an economist.) I am not alone in this regard, as I am at the peak of the baby boom. Many others like me have aging houses in need of repair and kids in college in need of tuition. The baby boom (peak 1955, first child at 25+) has a lot of kids in college, own aging houses, and still puts some away for retirement. I have to wonder, how much of this purported negative savings rate is real?
  19. D H

    New LaTeX Additions

    What's going on? All math [math]E=mc^2[/math] is generating LaTeX Error: Syntax error , LaTeX Error: One or more directories do not exist, and similar problems.
  20. Who defines a "post-industrial economy" this way? Certainly not Europeans. There has been a divide between upper and lower classes throughout history. I don't think the huge divide that currently exists in the US is unavoidable or is indicative of a "post-industrial economy".
  21. Similar arguments can be made regarding the value of 0*infinity and any other number. I could argue that 0*infinity is -1, 0, 1, 1.5, or any other number. This is why we must say that 0*infinity is undefined.
  22. Perhaps Texas does some things right. We have not suffered the housing collapse seen elsewhere. On the flip side, real estate prices have not risen insanely. The two go hand-in-hand. The two primary reasons are the homestead exemption and no income tax. The homestead exemption means homeowners only the holder of the mortgage may force the sale of a home to cover nonpayment of a debt. People can protect their home by making payments on it while declaring bankruptcy on everything else. This has been misused (think Exxon), but it has saved a lot of people, too. Texas has no income tax and no state property tax. While an income tax is illegal in Texas, a property tax is not. The state doesn't give much out to schools and communities. The result: Counties, cities, municipality utility districts, community colleges, public school districts, you name it, all administer property taxes. These high property tax rates militate against escalating real estate values. When lenders do have to foreclose, they tend to sell at a reduced value to get the property off their hands. Because prices aren't escalating, lenders here do give out 0% down mortgages. Those 0% down mortgages have been a big source of the rise and subsequent fall in housing prices. I am not advocating that states use a property tax in lieu of an income tax. Simply replicate the effects seen here. The easiest way to accomplish this is to stop subsidizing those free mortgages. One way to do this: make the mortgage insurance escalate as the financed percentage of the home value increases.
  23. Bascule, do you know who promulgated this deregulation you are talking about, and when it was done? Do some research, you will be surprised. (Hint: "I Love Rock N' Roll" was one of the top songs of the time.) The policy changes happened a long time ago. The housing collapse is a slow build-up of ever-escalating prices, greed, and irresponsibility. While predatory lenders certainly bear some responsibility, I also blame the "average citizen". It is their greed and their fiscal irresponsibility that made them easy prey for the predatory lenders. The housing market collapse is just a modern version of tulipomania.
  24. The force varies a lot depending on the size of the rocket. The specific impulse of a rocket is a lot less size-dependent: [math]I_{sp} \equiv \frac F{\dot m g_0} = \frac 1{g_0} \left(v_e + (p_e-p_{\infty})\frac {A_e}{\dot m}\right)[/math] Some numbers (BIG thrusters): Shuttle main engine (three engines on the vehicle): Vacuum force = 2170 kN per engine Vacuum Isp=453 secs Chamber pressure: 18.9 MPal Soyuz 1st stage (four engines on the vehicle): Vacuum force = 991 kN per engine Vacuum Isp=310 secs Chamber pressure: 5.85 MPal
  25. A link to the article would have been nice ... The article is not the best written (it's free; you get what you pay for) but it is correct. A better interpretation is 1) temperature increases the number of collisions between particles and 2) temperature increases the fraction of collisions in which the activation potential is exceeded. Both effect to increase the reaction rate as temperature increases.
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