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KJW

Senior Members

Everything posted by KJW

  1. You would. No. You would record time slowing down for them, just as they would record time slowing down for you.
  2. KJW replied to Night FM's topic in Ethics
    Perhaps, but the point I was making was that even people who know much better than most people how bad cats are to the environment have cats as pets.
  3. For the proud hardcore bigot, that's no doubt true. But for those less inclined to reveal their bigotry, the relative obscurity of meaning provided by the initialism does provide some cover to those who express their dislike of DEI, bearing in mind that the meaning of "DEI" can be distorted to a strawman much more effectively than the meaning of "diversity, equity, and inclusion".
  4. Yeah, it even sounded ridiculous when I heard Trump say it. On an episode of "Planet America" (which I've mentioned before), a person who was interviewed pointed out that although the US government does spend money on condoms for HIV prevention, the number of condoms that could be bought for $100 million being sent to Hamas makes it so obvious that what Trump said was a lie. The problem with Trump isn't just that he lies, all politicians lie, but that he is so blatant at it. It is an example of the belief that he can do whatever he wants with impunity... and that is dangerous.
  5. I recently read a suggestion from someone that instead of "DEI", people should be forced to use the full term "diversity, equity, and inclusion" so that when they say they are against diversity, equity, and inclusion, they are making it quite clear that they are an arsehole.
  6. Do you mean for example the $100 million worth of condoms being sent to Hamas? Not if there is less tax money to begin with because of tax cuts to the wealthy.
  7. KJW replied to Night FM's topic in Ethics
    It's funny you should ask that. There is a series currently being broadcasted on Australian TV called "Eat the Invaders" based on the premise that Australians should consider eating species that for whatever reason have invaded the Australian continent and have become a major problem. Each episode deals with a particular invasive species. Last week's episode was about feral cats, a major killer of Australian native species in accordance with the prey naïveté hypothesis. And indeed, even pet cats kill lots of creatures if they are allowed to roam the neighbourhood. Anyway, during the episode was an interview with a researcher of the cat problem. But during the interview, she admitted to having a pet cat, and even that some of her colleagues also have pet cats. She said they were house cats, but nevertheless there did seem to be some surprise over the revelation.
  8. What do you expect "change the rules" to mean in practical terms? Nobody is going to click on your link. If you want there to be any discussion, it is up to you to post something to discuss on this forum. Otherwise, it is no skin off our noses if there is no discussion because you didn't post anything to discuss.
  9. In what way is any of this contrary to the notion of abiogenesis put forward by science?
  10. No, the "agenda" of most here is science. Bear in mind that this is an international website with people here from countries other than the USA. For example, I am an Australian. I'm guessing that most scientists tend to lean towards the left, perhaps because they see the policies of right-wing political parties as tending towards evil. Here's an example from my own country: The previous government (the right-wing major party) trialled a policy whereby 80% of a person's social security payment would be placed into a cashless card account that was operated by a particular private company. There were tight restrictions on what this money could be used for as no cash could be obtained from the account. The message was that the people on social security payments were unable to manage their own money (often referred to as "taxpayer's money") and needed to have their spending restricted by the government (via a private company). Although the government intended to have this policy extended to most if not all people on social security payments, the trials took place in locations with largely indigenous populations.
  11. Yeah, I did consider this, which is why I placed "primordial soup" in quotes.
  12. Given that the building blocks of life are molecules, it seems reasonable to assume that life arose from molecules in a "primordial soup". What viable alternative possibilities are there, and also, how does science explore such possibilities? It's all well and good to offer up exotic possibilities, but unless you also offer up a way to explore such possibilities, you haven't really said anything useful.
  13. The two [math]x[/math]-values of the intersections are: [math]1 - x^2 = y^2 \\ \sigma^2 (5 - x)^2 = 25 \sigma^2 - 10 \sigma^2 x + \sigma^2 x^2 = y^2 \\ (25 \sigma^2 - 1) - 10 \sigma^2 x + (\sigma^2 + 1) x^2 = 0 \\ x = \dfrac{10 \sigma^2 \pm \sqrt{100 \sigma^4 - 4 (\sigma^2 + 1) (25 \sigma^2 - 1)}}{2 (\sigma^2 + 1)} \\ = \dfrac{10 \sigma^2 \pm \sqrt{4 - 96 \sigma^2}}{2 (\sigma^2 + 1)} \\ = \dfrac{5 \sigma^2 \pm \sqrt{1 - 24 \sigma^2}}{\sigma^2 + 1}[/math] where [math]\sigma = \tan\theta[/math], and [math]\theta[/math] is the angle between the surface of the cone and the central axis of the cone.
  14. I often say to people "nobody knows chemistry". This hyperbole comes from my observation that quiz show contestants who seem to know about physics, mathematics, biology, astronomy, geography, history, literature, etc seem to not know about chemistry, passing or getting wrong rather easy questions. It seems to be the one subject that very few contestants know about.
  15. Of course it is possible, but how likely it is I cannot say. However, prior to my first post, I did look at the link to check if this question was indeed part of a maths test rather than simply a textbook exercise, and could find no indication of which it is. I checked because I wanted to know the cost to the student of getting the question wrong, and therefore the importance of having been given the definition prior to the question.
  16. I don't know why it would matter, unless they were taught something wrong. It matters because the student was expected to know the correct answer and therefore should have been taught how to correctly answer the question. As I see it, answering the question is simply a matter of knowing a definition, and therefore marking the student wrong if the definition was never taught is wrong. How many people know that a circle is just the perimeter and doesn't include the area inside? Or that a sphere is just the surface and does not include the volume inside? It seems like a subtle point to require the student to know unless it had been explicitly taught. And if the student was taught this, then the student should have correctly answered the question. But here we are debating the answer to the question (which is simply based on a definition) without the context of what the student was taught.
  17. https://en.wikipedia.org/wiki/Solid_of_revolution
  18. One thing that was not mentioned was what the student was taught prior to being given this question.
  19. Presumably, this means that sodium hydroxide should be added to the tartaric acid first, then potassium hydroxide. I've never seen the dissolution of sodium hydroxide in water be violent, although it does get quite hot. Perhaps adding water to powdered sodium hydroxide is violent, but who uses powdered sodium hydroxide (it's normally in pellet form). Perhaps the KOH (and NaOH) should be assayed by titration.
  20. You could also use hot water. Hot water is better than warm water. 🤪
  21. A difficulty with pool leaks is distinguishing between leaks and evaporation. In my case with a salt-water pool, I replaced the lost water with fresh water until the electrolytic chlorinator stopped full output, indicating a leak and not evaporation (salt doesn't evaporate).
  22. Did you check the waste-water line from the filter (causing loss of water when the pump is on)? This was the first thing the professional checked.
  23. I had a pool leak about a year ago. I called in a professional to locate and fix the leak(s). One of the things he did was to get in the pool under the water and place drops of dye near the places where the leak was most likely to be, carefully observing any movement of the dye that would indicate a leak.
  24. For arbitrary function [math]\psi[/math], and [math]x^\alpha[/math] and [math]\dfrac{\partial}{\partial x^\beta}[/math] as operators: [math]\dfrac{\partial}{\partial x^\beta} \Big(x^\alpha \psi\Big) - x^\alpha \dfrac{\partial}{\partial x^\beta} \psi = \delta^\alpha_\beta\ \psi[/math] Thus: [math]x^\alpha[/math] and [math]\dfrac{\partial}{\partial x^\beta}[/math] are conjugate variables (operators) for [math]\alpha = \beta[/math]. Note that: [math]p_\gamma = -i \hbar \dfrac{\partial}{\partial x^\gamma}[/math] So that: [math][x^\alpha,p_\beta] = x^\alpha p_\beta - p_\beta x^\alpha = i \hbar\ \delta^\alpha_\beta[/math]

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