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Showing content with the highest reputation on 08/17/22 in all areas

  1. https://theconversation.com/explainer-why-are-we-afraid-of-spiders-26405 I’ve been wondering a small bit about the irrational fear evoked by spiders and snakes. Some people say there may be an evolutionary component to it as a few of these creatures can potentially be deadly. But our visceral response to them seems to be far more excessive than the actual threat they would have posed throughout human evolution. Humans obviously have a limited capacity to empathise with animals. We can anthropomorphise our pets and we might admire animals in the zoo. But as the philosopher Thomas Nagal pointed out, “What is it Like to be a Bat?”. In other words what is the sentience of these creatures like? They can’t just be inanimate robots as they display complex behaviour. Perhaps they live in a barely self-aware oneiric sort of existence that will be forever unknown to us. Some exotic creatures may possess a mind so “alien” to ours that it becomes repulsive when we try to project a degree of consciousness onto it. So might the creepiness of spiders and snakes be more of our instinctive reaction to their unfathomable psychology rather than the actual biology of them?
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  2. I think @studiot may have made a valid point. As an example consider that your initial mixing of 2 moles of hydrogen with one mole of oxygen increased the entropy of the mixture by about 1.89 R. In the absence of reaction no energy change occurred and hence there is none to recover in the reverse reaction. However, mixing is an irreversible process (in the thermodynamic sense) and unmixing the products of the reverse reaction back into their pure elemental states will require quite a bit of unbudgeted additional work input.
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  3. It really depends on what you application is. If you're looking for a general CAD solution and can afford it, I'd say SolidWorks. I have juggled back and forth from SolidWorks and Fusion360 for around 4 years. If money was no object I would use SolidWorks hands down. The macro functionality alone makes it worth it. When I used it heavily in the DoD I had a "toolbox" of macros to create automatic 2D & 3D drawings (i.e. gears, splines, airfoils). You don't need an internet connection to run SolidWorks and the assembly functionality is much more robust. They offer an educational version for $50/Year or something, but you of course cant capitalize on any of your designs using it. I eventually broke down and just started using Fusion360. It's pretty polished but can be clumsy at times. I like that I can access projects from anywhere. They're starting to implement more "pay-to-play" features and you can only have 10 active parts at a time (ridiculous). Now that I'm a student it's plenty to build apparatuses or rack components. But be warned with Fusion360, if multi-page and robust drawings are necessary for your work. They only allow you to create one page at a time and its maddening. They now have 3DEXPERIENCE SOLIDWORKS for makers that looks like its $100 a year and pretty feature dense.
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  4. Due to the Moon's tidal effect, the Earth's period of rotation increases by about 1 sec every 50,000 yrs. (in 50,000 yrs, it will take the Earth one second longer to complete a rotation.) As to affecting human's lives, It already does, to a certain extent. We have reached a point where accurate time measurement has become vital to a great number of fields. Because of that, the need for a standardized unit of time became very important. This is the second. For a long time, the second was based on the Earth's rotation. That is, until it became apparent that this wasn't a constant. The second was switched to be based on something known to be constant, and fixed on that value. The Earth's rotation still changed over time. Sure, it was only by microseconds a day per year. But the effect was accumulative. For example, imagine a clock that runs slow by one second per day. after 1 day, it will be late by 1 second, after two days 2 sec,... after 60 days, its behind by a full minute, etc. The same thing happens with the Earth, from the time we set the length of the sec to a fixed value and now, our Clocks(based on that sec) and the rotation of the Earth vary slightly Just a tiny bit each day, but it adds up over time. So, in order to keep them our clocks from drifting too much from the position of the Sun in the sky, every so often a "leap second" is added to our time keeping systems, to line them back up again. (kind of like resetting that clock that runs slow from time to time).
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  5. Yes. When hydrogen is burnt with oxygen the reaction is 2 H2 + O2 -> 2H2O. You break 2 H-H bonds and an O=O double bond, which requires energy. But the energy you get back from forming 4 H-O bonds, i.e. H-O-H + H-O-H is greater, by 286kJ/mol of water. If you run the reaction backwards, as you do in electrolysis of water to make hydrogen and oxygen, this is the energy you have to input to do it.
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  6. I am a bit skeptical of the promise of large scale weather modification. I think the reason that central Australia is desert is a persistent lack of on-shore winds capable of carrying moist air into the interior, not lack of evaporation over oceans when we get them. There is a preponderance of high pressure systems due to Hadley cells, that drop dry upper level air down over desert areas, with prevailing low level winds blowing coast-wards and/or blocking on-shore winds as a result. I think that is the case for the Sahara and other desert regions too. Mountain ranges and their rain shadows can be a big factor for some deserts too. Greening desert fringes can have an impact but I suspect it works because human activities - introducing grazing livestock, including gone feral (goats, donkeys, camels and rabbits in Australia) - is why they lost their vegetation; in combination with managing those pest species it is possible to bring back vegetation. Whilst vegetation can increase local precipitation it isn't a huge effect; these regions are still highly dependent on occasional rainfall events. There can be - at least over the medium term - some regional greening from changed weather patterns; North West Australia is getting more rainfall out of those rainfall events when they occur - not necessarily more of them or regularly. How that plays out with much raised temperatures is still a question. Other regions of Australia - agriculturally productive ones - are getting less rainfall. I am seriously concerned about the longer term prospects with global warming; 1 C of global average warming is making about 1.4 C of warming on the ground in Australia, so 3 C (which we are on track for with us reaching zero net emissions from a lot more serious commitment than we are seeing) could mean temperatures rise over 4 C. I think we will reduce our emissions a lot but not enough reach zero within the timeframe needed, so 4 C or 5 globally averaged, with temperatures on the ground raised 5 - 6 C seem not just possible but likely; our greening efforts are going to be in big trouble, along with the health of economies capable of undertaking them. That is still assuming reality is nearer the mid-range for climate sensitivity; if it turns out higher it can be worse again. Arid zone plants and animals are only tough in comparison to those in milder conditions; in many cases their survival prospects have been borderline all along - surviving but only just is the rule.
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  7. I'm an atheist and I see all the good around us. I don't disbelieve in God so I can sin without consequence, that has nothing to do with it. I disbelieve in God because there is no evidence that God exists; that's the issue. In the absence of a God, my philosophy is treat others the way you want to be treated.
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  8. Getting complete nutrition from a vegan diet is difficult - we humans evolved as omnivore hunter-gatherers. If simplicity you seek, a soy milk or pea milk with added B12 is a good start. Then whole grain, nuts, green vegetable (broccoli is handy as it provides both K and C), yams, mushrooms, and olive oil. And a little variety in your pulses (which are lentils, beans, chickpeas, soy) helps reduce gaps in nutrition. If you are willing to bend a little it may not be a bad idea to once a week have a few free range eggs or a few sardines. Compare how you feel (energy, alertness, strength) on the pure vegan diet with the almost-vegan diet.
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  9. Yes, cyanobacteria are clearly bacteria and not plants. Plants and animals had a common ancestor roughly 1.5 billion years ago. Arthropods appeared about 500-600 million years ago, the order of Mantodea is about 145 million years old.
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  10. “It's not that complicated. We hate them because they're threatening and ugly.” - drumbo But then why don’t people find sharp objects creepy? Jagged rocks could trip you over and blades can be used as weapons. They’d be far more threatening in an evolutionary sense. Yet spiders can somehow have a slightly frightening effect. We don’t find smaller insects like flies creepy as they can be easily dismissed as automata. But the larger the spider, the scarier it can be for a few people. I don’t think anyone would be afraid of a lifelike robot spider. So I imagine the fear of spiders comes from misplaced sense of empathy with animals and pets. It goes awry when we apply it to more peculiar species. https://www.google.ie/amp/s/www.psychologytoday.com/ie/blog/tech-support/201501/3-things-being-cat-person-or-dog-person-reveals-about-you%3famp “The phrase pathetic fallacy is a literary term for the attribution of human emotion and conduct to things found in nature that are not human. It is a kind of personification that occurs in poetic descriptions, when, for example, clouds seem sullen, when leaves dance, or when rocks seem indifferent.” “Some scientists believe that the belief in creator gods is an evolutionary by-product of agent detection. A spandral is a non-adaptive trait formed as a side effect of an adaptive trait. The psychological trait in question is "if you hear a twig snap in the forest, some sentient force is probably behind it". This trait helps to prevent the primate from being murdered or eaten as food. However this hypothetical trait could remain in modern humans: thus some evolutionary psychologists theorize that "even if the snapping was caused by the wind, modern humans are still inclined to attribute the sound to a sentient agent; they call this person a god". - Wikipedia “All of their answers had one underlying theme, one unifying factor that made the person or situation creepy: the presence of an ambiguous threat. Not something frightening or strange, mind you. A killer on the loose is frightening -- there's no ambiguity in the potential danger there. And your nerdy, socially awkward cousin may be strange, but he's harmless, and therefore not creepy. Creepiness is a function of uncertainty. In a paper he wrote with undergraduate psychology student Sara Koehnke, McAndrews explains, "It is our belief that creepiness is anxiety aroused by the ambiguity of whether there is something to fear or not, and/or by the ambiguity of the precise nature of the threat (e.g., sexual, physical violence, contamination, etc)." - KQED
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  11. What utter rubbish. It's much easier to tamely accept the indoctrination you got as a child, than to question it. Especially when that doctrine has been specially designed to appeal to weak-minded people, who respond like puppies to the fake love of an imaginary friend.
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  12. This is where atheism and critical thinking part company; you smugly decide an entire, history of philosophy as weak minded; and so dismiss Taoism, Buddhism, Jesus etc. by equating it with scientologism and the westboro baptist church, talk about throwing the baby out with the bath water... BTW The +1 you got for that post offended me, so I peacefully removed it...
    -1 points
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