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OldChemE

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Everything posted by OldChemE

  1. What is a CME? The first time you use a TLA in a post you should define it, just for the benefit of those who may not be familiar with the TLA. (TLA: Three Letter Acronym)
  2. When I want to know a square root, I just pull my old slide rule from my desk (it uses the Log method).
  3. I've always been fascinated by the approach of the ancient Greeks-- Their top tinkers were truly philosophers, but not scientists. That is, they developed their ideas by thought and reasoning (such as Geometry) but did very little experimentation-- no scientific method. Aristotle, if I recall correctly, had some very interesting thoughts on motion, but never verified by experiment (and he was wrong).
  4. I too remember better that which I write down. After watching my students work and noting who learned and remembered the most, I came to the conclusion that remembering, for most people, requires that the brain process the information in some form. Reading alone does not seem to cause most people to process the information. Read-interpret-write seems to cause sufficient processing to make information stick better.
  5. OldChemE

    about charity

    This is a very important topic-- but I think one key aspect is that charity, per se, is not necessarily good (for reasons mentioned above). What is important is that Charity supported should be charity that in fact does good in both the short and long term. For example, if a person cannot support themselves, should you (1) give them money or (2) help them find a job so that they can support themselves (the old give a man a fish or teach a man to fish analogy). Similarly, should you give money to the charity that provably helps its clients or to the one that makes a heart-rending appeal but largely lines the pockets of its founders?
  6. I hardly think wikipedia can be referenced as a source for the proper definition of a religious sect that existed thousands of years before the various contributors wrote their wikipedia article, and which even existed for an extended period before the current versions of the religious texts were decided by a committee of scholars. Those that try to dictate what constitutes 'being a Christian' are merely in a labeling exercise, not a source of fact. The various subsets of Christian Churches willingly allow participants to self-identify. This, and the fact that we have so many variations of Christian doctrine (Protestant, Baptist, Fundamentalist, etc, etc, etc), clearly indicates that the Christian Church recognizes shades of belief.
  7. For 30+ years portions of our society have been teaching their children that if they try hard enough they can be anything they want-- which totally ignores the reality of talent and ability. This makes some people unable to cope with failure or even being "average." For some people, it seems, being 30 and not yet rich and famous is very, very, depressing.
  8. When I retired from engineering I took a job as the Science Teacher fora small Christian High School. One of the concessions I got from the school was that we would teach science using the best available secular textbooks-- No religious science books. At the next 'Parents Night' one of the parents asked me point blank how I could reconcile Science and religion. This was my answer: "You believe God created the World. In my classes the students will learn how the world works. In Religion class your students should learn how to make ethical use of what Science provides." The parents accepted this and we had no later issues.
  9. Given the huge amount of historical information available about so many topics in our modern age, I think the REAL curiosity would be if these sorts of alignments of data DIDN'T happen.
  10. 3D games are not like reality-- but close. Computer programming does not produce any effect that is truly random-- while reality does. Computers can be programmed to simulate random behavior sufficient to fool the users, but code still follows rules.
  11. My wife lives, the other dies. Aside from the fact that I love my wife,I took a marriage vow to protect her. The marriage vow overrules all other considerations. Always
  12. Look up "Activity Series of the Elements"
  13. You are falling into a mental trap by thinking of circumference/diameter as two rational numbers. Consider this: If the diameter is 1, the circumference is 1 times pi, which is irrational. If the diameter is 2, the circumference is 2 times pi-- which is still irrational. In fact, in any circle, if you could measure it to an infinite number of decimal places, you would discover that one of those two measurements is an irrational number. Dividing two numbers, one of which is irrational, gives you an irrational result.
  14. I'm wondering what the OP means by spirituality-- since very religious book I know of, particularly the Bible, clearly condones eating meat.
  15. Look at the units associated with Avogadro's number, and you should be able to write a much simpler equation that directly converts grams to atoms. When you have a problem involving different units of measure, you can use the units to determine the appropriate equation. Avogadro's number is atoms/mole, atomic weight is grams/mole, sample size is grams. How could you multiply or divide these three sets of units in order to have a result which is in units of atoms? Do this and you will have your answer.
  16. OldChemE

    0÷0

    Wrong, unfortunately. 0 divided by 0 is undefined. Why? you might ask? The rule in math is that anything divided by itself is 1. This would argue that 0/0=1. However, zero has peculiar properties that prevent this. For example, 16/16 = 1, but 16 = 4 x 4, so 16/16 is the same as 4x4/4x4. but 4/4 = 1, so 4x4/4x4 = 1 x 1 = 1, and 16/16 = 1. The point of this example is that if we divide a non-zero number by itself, we always get an answer of 1, even if we factor the number. Now, consider 0/0. 50 x 0 = 0, and 1 x 0 = 0, so 0/0 could be 50x0/1x0. if 0/0=1, then this version of 0/0 = 50. The point here is that the answer changes depending on what numbers were multiplied to make zero. This, then, defeats mathematics, which is why the result you are seeking is "undefined" in mathematics. Attempting to divide any number by zero, even zero itself, creates inconsistencies in mathematics, and is not permitted.
  17. OK-- I think I see what the OP's question is-- If I'm wrong, forgive me. I think the question is why did we need Vacuum tubes (and later transistors). Prior to the digital revolution, all signals were analog. This included radio and TV. radio/TV signals as received from the air are very weak, and have to be amplified. That was the function of the Vacuum tubes and later transistors-- amplification. Specifically, a small analog signal on the input could be made to produce a duplicate signal with larger voltage swing at the output. Thus, the purposes of these devices was not to transmit voltage to the screen or speaker, but to raise the magnitude of the signal to make it strong enough to drive the speaker or output device. Many modern devices don't require the high voltages so this function is becoming less common.
  18. I would be interested in knowing what the statement "absolutely wrong" means? If it means that it is wrong to test problem solving skills, then I would have to disagree-- there is no place in science or engineering for people who do not have problem solving skills. If you mean that the statement is not true, then you are wrong or misinformed. I took exams all through university that required demonstration of problem solving skills and I wrote many, many exams myself as a High School science teacher that required problem solving skills. To paraphrase what I said in my earlier post, the key distinction between a project and an exam is that only in the exam can the teacher know with a fair degree of certainty that the results truly reflect what the student can do, as opposed to what the "student (and friends and internet)" can do. This is important to know. It does not, of course, determine the entire grade, but it is important. Projects cannot provide this degree of insight.
  19. I would argue that Computer Science is NOT science, it is Engineering. Pure sciences deal with discovery and explanation of the ways in which things arise, while engineering deals with application of scientific information to real world situations. Clearly (at least in my mind) the things that so-called Computer Scientists do is an application of mathematics and/or electronics and/or physics, which makes it a branch of engineering.
  20. The concept that students cram before an exam, instead of learning steadily is not true for many disciplines. In sciences and engineering, exams often focus on the ability of the student to solve problems, rather than on memorized facts. As such, the exam is actually asking students to demonstrate problem solving skills just like those done in class and for homework, with the only distinguishing quality being that during the exam they have to show that they actually have the skills themselves, while in the case of homework they may have completed the work with help of someone else. I believe this is a valid purpose above and beyond projects. Which is why, after I retired from Engineering and took up teaching for 7 years, I built my exams in Science classes just this way, and graded those exams on the basis of demonstrated problem solving skill, not just on correctness of the answer (in fact, in my exams, students were required to show their problem solving methods in order to receive a score-- a numerical result alone, with no supporting calculations, was an automatic zero no matter how correct).
  21. Time line when religion will be obsolete?? About the same time that people stop believing in magic, weight loss miracles, and winning money in the lottery
  22. EquationsProbles1 Yes, your equation is properly balanced. Your problem with this lies insolubility. Both of your sulfate products are very, very, soluble in water. What this means is that the products never actually form-- the individual ions stay in solution and you can only get the sulfates out by evaporating the water. As for the Ammonium nitrate, it is also soluble in water to the tune of about 20 moles per liter (118 grams per 100 ml according to my old handbook of chemistry and physics). When all the products of a potential reaction are soluble, the final compounds are never formed-- its just a big soup of ions floating around together (and fyi-- If I recall correctly, its not enthalpy that determines if a reaction if favorable, its Gibbs Free Energy, which also takes into account Entropy. All the enthalpy change won't do it if entropy is too unfavorable). I realize I'm violating the homework rules by giving an answer, but this discussion seems to have dragged on.
  23. In several of the Nuclear Power plants I worked on (designing) we had double valves on all pipelines exiting the reactor containment building. No valve is perfect (they all will leak-- even if only a tiny amount). Safety regulations required that we test the valves periodically to ensure leakage was within the acceptable range. We did this by pressurizing the space between the two valves with compressed air and measuring the rate of air loss. This was a very good test, because normally the lines contain water, so using air amplified the leakage (compared to water) and gave us a test of adequate sensitivity.
  24. The Laws of motion-- definite yes (and for engineers especially the three forms v = v(0) + at, x = x(0) +vt + 1/2 at^2, and v^2 = v(0)^2 + 2a(x -x(0))) Also the various formulas for Kinetic energy, Potential energy, and Work
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