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Everything posted by OldChemE

  1. Better to have the surgery that doesn't do the damage, and not have to wait.
  2. I would start with an average High School Algebra book. Pearson and a number of other textbook publishers make very good ones. They tend to be aimed at a population of students that have a wide range of learning styles, so they have written material, pictures, examples and other such things. Once you know what learning style fits you best you can then move on to more tailored textbooks. There are more modern teaching systems, such as "Eureka Math" but they do not have well-developed reading material and tend to be more narrow in the learning styles they address. I've taught Algebra using the older books and with Eureka Math, but the older books seem to have broader success.
  3. Not as much as in the past. The new robotic surgeries have made remarkable strides in avoiding damage ( as verified by personal experience)
  4. As iNow says, we are all ruled by chemistry. So, the discussion does indeed depend on how you define the terms. Traditionally free will has been regarded as the ability of an individual to make its own decisions using its own brain. This is still the case. Our decisions may be driven by internal factors rather than rational thought-- but ultimately, our decisions come from within us. And, since our neural connections are driven by our experiences in addition to genetics, we are all to some degree unique. Thus, I would argue we have free will. However, not all would agree with me.
  5. The question comes down to this: Should we ban X because X may lead to damage to the person who chooses to do X? As long as the individual who chooses X is the one who faces the risk, then a free society has no moral right to ban X.
  6. Mine book says non uniform in single loop, of course, but also toward the ends of a solenoid of finite length. I think the OP has been well answered by others in any case, so this probably isn't of any importance.
  7. I can't figure out how you conclude this. My old physics textbook clearly states that the magnetic field within a wire coil is "NOT uniform."
  8. This is the kind of problem that is more easily solved if you step back before turning the math crank. Look at y = x^2 and y = 16&x. y = X^2 is a parabola that passes through the origin. y = 16^x is an exponential function, and on the positive x side it rises faster than the parabola-- so it is obvious that there will be no solution for x > 0. On the negative side of the graph, 16^x approaches zero asymptotically, and is already 1/16 when x = -1 (while at x = -1 the parabola is at y = 1). Thus, it becomes obvious that the solution must lie in the region -1 < x < 0. I did a quick sketch of the two functions and it was equally obvious the crossing point had to be somewhere close to -0.5, as stated by Studiot. Understanding the shapes of functions makes trial and error, and heavy math, both unnecessary.
  9. OldChemE


    Could you be confusing chemical energy with the energy content of mass? The Free energy of different compounds and material does vary-- but that only involves a portion of the total energy.
  10. if the first point is (0 -3), as stated, then the equation is y = x - 3, not y = 0.5x + 3. If it was intended to type (0,3), but typed as (0-3) in error, then y = 0.5x + 3 is correct.
  11. And who is to decide what constitutes "how much they contribute"? Are we talking money? agricultural products? art? inspirational writings? Great food recipes? Who is to decide what constitutes a good contribution versus what is ultimately bad for society? Philosophically this might sound good but I do believe that from a practical standpoint it is a non-starter. What you are basically doing is trying to figure out a formula to increase the influence of the population that you prefer to support. That is in the same class as gerrymandering and other political pursuits. The beauty of the constitution is that it lays out principles for representation that are supposed to be above this sort of thing, and much of the time it even succeeds.
  12. iNow: I concur with both the caveats. I too would like the system to be in balance properly.
  13. You've missed the whole point of the Constitution. The Senate is designed to give equal voice to each state-- which is (in some sense) a balancing of cultural differences, while the House of Representatives gives equal voice by population, which gives a balance by population. The whole purpose is to make it so that legislation is supported both by region/culture and population. What you are suggesting takes away that balance.
  14. It seems odd to me that we have multiple theories to explain an effect that may or may not exist. Personally, I haven't found that time seems to pass more quickly as I age. Is there any actual scientific evidence that the perception of the passage of time changes as we age? or is this a case of science trying to explain anecdotal perceptions?
  15. I don't disagree-- but I think we have different tolerance levels as to what kind of engineering challenge counts as an issue.
  16. I recall from many years ago similar projects being discussed. My recollection is that there were no structural issues-- but there were efficiency issues. Solar power already evaporates water for the entire surface of the ocean and delivers it to land in the form of precipitation. This, of course, is of limited efficiency because some of the precipitations falls on the oceans, or in places it cannot be efficiently used. However, since floating desalination systems detract from the natural evaporation, they would have to be correspondingly more efficient to make a net benefit. The challenge is in making the floating system, and the energy required to retrieve the water thus produced, sufficiently efficient to make it financially superior to capturing the natural precipitation.
  17. I think my grandfather-- who was a well-educated and thoughtful man, had it worked out.. When my Father graduated from college, my grandfather sent him a handwritten note with the following message: "Wishing you throughout the years, a fullness of happiness, a diligent pursuit of purpose and a life of fruitful accomplishments (June, 1941)
  18. I think there is a careful distinction to be made. "getting back" at some one can lead to a bad situation, and anger that cold hurt you. One the other hand, if the person showing intolerance and hatred can be made to experience the logical consequences of their behavior, benefit can result. This is much the same situation as crime and punishment. The legal punishments established for certain crimes are (in theory at least) balanced by the severity of the crime-- and are fair. Revenge, on the other hand, is not considered right. When I was teaching it was not uncommon for individual students to behave badly toward others on occasion. As a Teacher, I did not let the students "get back" at the individual, but I did apply school-sanctioned punishments, so that the intolerant student experienced consequences that were clearly connected to their behavior.
  19. Fiber does not necessarily mean poor nutritional foods. For example-- eating lots of vegetables (particularly things like Broccoli) will give you plenty of fiber. Certain fruits and beans provide a similar benefit in terms of fiber. All you need to do is eat a little less meat and fewer highly processed foods.
  20. Logically, your equation should work fine. It is mathematically equivalent to multiplying the number of elements in the sequence by the mean number of the sequence, which always gives the sum. To see why, lets look at this set: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. To get the sum we could add 10+1, then 9+2, then 8+3, 7+4, 6+5.... all of which add to 11. The mean of the sequence is 5.5, which is just (10+2)/2. If we multiply this mean by the quantity of numbers in the set (10) we get 55, which is the sum of 10+1, 9+2, 8+3, 7+4 and 6+5. The equation that corresponds to my example is ((n+k)/2)(n-k+1), and your equation can be manipulated to match this equation.
  21. Those who pass laws must be 100% subject to the same laws. For example, Retirement systems and medical care for legislators and government officials have to be within the Social Security and Medicare systems. If they had to depend on it they would be more likely to try to get it right.
  22. If you look at the history of earthquakes in Southern California you will see something very interesting. The San Andres fault has a sort of "dogleg" or hockey stick bend in Southern California. The pressure from the northward movement of the Pacific Plate, along the San Andres fault, pushes against the dogleg. On a diagonal line roughly to the Northwest from this dogleg, there is a history of additional earthquakes, not on the San Andreas fault. From an engineering perspective, it is as if the pressure at the dogleg is stretching the crust to the northwest, or maybe even (some day) forming a new fault line to the northwest branching off the San Andreas fault. The Ridgecrest Earthquakes were on this diagonal from the San Andreas fault.
  23. I see the logic behind your point-- its a good one. I just think that in science we are not nearly as close to the point of knowing as much as there is to know. When it comes to ultimate knowledge I think we are barely to the beginning of the "S". Of course, I realize I cannot prove this.
  24. Yes, but history shows that here is a new "S" curve for each new technology. As long as Science is used to discover we will likely continue to produce more "S" curves. One very exciting thing about Science and Engineering is that we do not yet know what we do not know.
  25. We've been seeing similarly cooler summer days in my part of Northern Nevada. But-- to my view it seems to correlate to global warming. What has happened is that the past couple of winters, especially this last one, have been much warmer. 9 years ago, when we moved here in retirement, we hit nightime lows of -25 F on several occasions, and had snow. This past winter we rarely dropped lower than +10 F, and had very little snow. Instead, we had lots of rain, and the rain continued into the spring. Now we have groundwater at the surface, and frequently the evaporation builds unseasonal cloud cover-- so we are seeing slightly cooler days than normal for the summer. To my relatively untrained eye it looks to me like the overall warming (and associated evaporation) is bringing more moisture to the high desert and the effect of that moisture is to moderate the extremes-- giving warmer winter/cooler summer.
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