exchemist
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......."vaginitis".......... 🤪
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Did contaminated fuel cause the Baltimore bridge disaster ?
exchemist replied to toucana's topic in Engineering
I have just watched an interesting video made by a Marine Chief Engineer, on this incident: He is not privy to any inside information but he can make certain deductions from looking at the footage of the incident. They key points I got from this were that: (i) the emergency generator did not restore power within the 45seconds mandated by SOLAS rules. It came on but after about a minute, too slow, why? and (ii) there was black smoke from the funnel after the restoration of power after the blackout. He does not believe they would have had time to restart the main engine, which would have shut down when electric power to run its fuel pumps etc was lost. So it cannot have been from the main engine. It must therefore have been from trying to restart the main generators. But these are indeed supposed to run on MDF when manoeuvring close to port, which should not produce black smoke, even during start-up. So the finger of suspicion points to the fuel fed to the main generators. Possibly there was something badly wrong with the MDF or possibly they were incorrectly trying to run the gensets on RFO too soon and something went wrong with the switchover from MDF to RFO. The ship should have been able to operate its rudder even on only the emergency backup genset, but without the propeller, the turning effect from the rudder would have been very limited. He did make the comment at the end, just in passing, that if the port regulations had required tug assistance until out from the bridge channel then the outcome would have been different. That thought had occurred to me too. Expecting these large ships to get out on their own, with the tidal current in the river estuary......well.....I don't know. -
You owe Einstein an apology then. As has been already pointed out, you have no relative motion between any of the components in this setup, so time dilation does not occur anywhere. Look up time dilation and re-establish what it is, before you go any further. You are speaking here about time delay, which is not time dilation. Secondly, the phase shift on reflection of a wave is 180 deg, not 90deg and it is not a red shift, as it does not alter the frequency. Thirdly, this sort of nonsense is starting to have a familiar smell to me. I'm wondering whether neurological reference frames are more your thing............ 😁
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Dawkins or @Gian? 😁 Dawkins has I think mellowed somewhat with age and may even realise that throwing coconuts at the Aunt Sally caricature of religion he has spent years attacking is a is bit counterproductive. The Four Horsemen of New Atheism have at times come across as evangelical preachers!
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I wonder if that could be an effect caused by a mix of reddish and greenish light, appearing to the eye as a yellow tint. I don't think anything in blood will actually fluoresce, not least because the UV will be attenuated under water more than visible light. But the way light is attenuated by seawater seems to be quite complicated. The red end of the visible spectrum seems to be absorbed more than the green and blue, but UV is also absorbed. And then there is the competing phenomenon of scattering which will scatter the blue more than the red.
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That's an interesting take on "cancel culture", that I've never come across before. I'm not aware of instances of speakers being denied a platform because they wanted to speak against religion. Normally it is because the speaker want to air views considered abnormally reactionary by the students. Has Dawkins, or anyone else to your knowledge, been refused an invitation to speak against religion? Ciao love and kisses 😆
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But surely, if he was complaining about the supposed need to be unduly respectful towards religion over 20 years ago, then today's "cancel culture" (if it exists) shows him to have been rather prescient, doesn't it? Or are you suggesting it is his iconoclasm that has brought "cancel culture" about?
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He doesn’t strike me as making a fool of himself in the remarks you quote. He seems to be arguing, rather intemperately, for people to feel free to attack religion, instead of, as he seems to think, showing it undue respect. Well, it’s a point of view, and not self-evidently silly, it seems to me. Why do you think it makes him look a fool?
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I found this paper on-line about hydration of starch which goes into some detail: https://www.sciencedirect.com/science/article/pii/S0144861722004477 From this it looks as if the hydration process is the opening up of the starch structure, replacing some of the internal hydrogen bonds between the sugar units of the chains (starch is a polysaccharide) with hydrogen bonds to water. Water that is chemically bound in this way will not make the, starch or dough, "wet", as it is chemically bound in. (In inorganic chemistry you may be familiar with the fact that copper sulphate can take an "anhydrous" (white) or a hydrated (blue) form. Both are dry crystals but there is more water bound chemically into the structure in the blue form. If you heat the blue form strongly it steams, losing water and turns white.) Presumably something similar can happen with proteins. So yes I expect your dough has bound water, which will alter the structure of the starch and proteins by inserting water molecules between chains, and also unbound water which makes the dry material wet to the touch, sticks the grains together in a lump and makes it feel doughy. I don't know how much water the starch will absorb, but I don't think it will be just a monomolecular layer on the outside of each grain. From the paper, I take it that it disrupts the internal cross-linking structure of the starch as well.
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what are all possible ways of testing 999.9 or 24k gold?
exchemist replied to kenny1999's topic in Amateur Science
You could try Archimedes' method, viz. establish the volume of the object via displacement and then weigh it, thus determining its specific gravity. This would only work for objects with a fairly large proportion of metals other than gold in them, but then that is the case for a number of the alloys used in jewellery: https://www.thoughtco.com/composition-of-gold-alloys-608016 -
That proved one prediction was right. It does not prove the theory.
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According to current models, perhaps.
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Surely that is not what science teaches, though? Science gives us predictive models of the physical world, none of which can be proven and consequently none of which can be said to be definitively right.
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But surely these all lighten the skin , by breaking down melanins or inhibiting their synthesis. That’s the opposite of what the OP is asking about.
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Breast sagging natural vs with a bra
exchemist replied to annie24's topic in Biochemistry and Molecular Biology
That’s what I did. She got on the scales and I put my hand under one breast, lifted it to the point at which the tension appeared to be gone from the upper slope, and noted the decrease in scale reading. Then ditto with the other. Not very accurate perhaps but gave us an idea. She had quite a generous, though not excessive, bust. Most of my other girlfriends had smaller breasts and a less earthy sense of humour, so the subject never came up with them. 😀 -
Indeed very hard to control for all the variables involved here. Purely anecdotally, my observation is that fatter people often eat more, and often they eat worse, i.e. more ready meals and junk food. Having said that, it is definitely not always the case, so there are other issues to do with varying propensity to convert calories to fat. Some of these effects appear to be hereditary.
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Breast sagging natural vs with a bra
exchemist replied to annie24's topic in Biochemistry and Molecular Biology
I have only had the opportunity to research a small sample ( 12) in the course of a longish life, but in spite of the considerable variety of shapes and sizes I have never observed any musculature in breasts, even though I belonged to a rowing club for over 30 years and married a rower. (I did once try to weigh them though. This arose from a discussion of the old-fashioned appreciative remark “Blimey, you don’t get many of them to the pound!” - a reference to how one used to buy fruit at the greengrocer. She was a nurse, so was happy, in fact highly amused, to enter into the spirit of the exercise. In her case about a lb each so it was true, for her.)