# jfoldbar

Senior Members

92

1. ## Bernoulli's principle

yep, i know. but i gotta start somewhere yes, i have learnt his from YT this is a very good point. im not a student. im just a regular dumb joe that sometimes likes learning all kinds of science stuff thats way beyond me. this crossed my mind too, and i wondered the difference (if any) between liquid and gas this is one thing i wonder too. how does what happens in a pipe, also relate to what happens over a wing yep. at the moment i want to keep it to bernoulli as much as possible. i realise because my end goal is flight, the discussion will spill over a bit. but try to keep to one subject at a time if possible, as im all ready getting lost thanks
2. ## Bernoulli's principle

but, at 8000m high, wouldn't the ratio of air molecules vs wing molecules be really different? when theres very little air, how can there be enough air molecules for the ones that bounce of the wing to be crashing into?
3. ## Bernoulli's principle

so, i was thinking bout this video, and i have a few thoughts. the vid shows the a fluid changing from a larger pipe to a smaller pipe. which means an enclosed space. but if this principle applies to the top side of a wing, would the concept be lessened because there is only one side. so when the air atoms are flying over the wing top, some of the atoms will hit the wing direction, but most will fly upwards. also, wouldnt this concept be lessened too by altitude?
4. ## Bernoulli's principle

thankyou. this was exactly what i was looking for. an explanation as to the "why". hhhmmm... thinking...
5. ## Bernoulli's principle

i decided i want to try to "understand" how a plane can fly. if thats even possible for a layman like me. so ive been watching a bunch of videos, but still so many questions. and you cant ask a video anything. so, i thought i would try here. because this is essentially a tricky subject, i thought i would break it up into mini subjects. so the first subject is Bernoulli's principle. now i know this is not the whole picture of why a plane can fly, but it is some of the picture. so, first up i thought it better to try to understand this. so, as i understand, Bernoulli's principle states that an increase in a fluids speed lowers its pressure. the thing i cant find on any YT vid is the 'why'? what is happening on an microscopic scale? even though my end goal is to try to understand flight, for the sake of simplicity, we should try to keep it to Bernoulli's principle as much as possible, i will make a new thread later for the next part. try to keep answers in simple language. (im a laymen). but detailed. thankyou
6. ## men vs woman

respectfully, im going to leave it here. you are not grasping what im asking and i cant explaining it any better.
7. ## men vs woman

ok ill try again. forget the hippocampi for a moment and just consider that men and woman are different. in many ways. physically, mentally and emotionally. try replacing strong fred with weak sarah. strong fred may not be a gym bunny but hes stronger simply because hes male. if sarah wants to put it over fred, she could go to the gym and become iron woman. may stil not be enough. but what if she also goes and shoots up on all these drugs that essentially make her male. she is no longer sarah, let alone weak sarah. the the question if sarah is stronger than fred is invalid because sarahs not here any more. so the average woman has more trouble reading a map than a man. this could be some impulse/ learned trait that stems back thousands of years to hunter gatherer days. but that is what makes her a woman. those intrinsic difference are what we (generally)love about the opposite sex. take those away and they wouldnt be the opposite sex. if we could scientifically calculate every difference between man and woman and go back in time to make the adjustments so that there are no differences, then there wouldnt be man and woman. thus making the question invalid. on the small scale little girls that get cars instead of dolls can be tom boys when they grow up. so by the mum giving them cars they slightly take away 'the little girl'. stretch this over history and any change that we could have done to change the differences in people would result in there being no difference thus removing the need for us to ask the question. so we have all variety from the most masculine men to the most feminine female, and every variety in between. we have men that act more like woman do, and we have woman that act more like men. these are the few. of course there is no way to determine throughout history were various leaders/rulers whether male or female, a manly man or a womanly man, or vice versa. but statistically it stands to reason that the majority would have been within the normal range. what i mean is if you got every male leader from every time and lined them up, the majority of them would be manly men. but of course this doesnt take away from the fact that there would have been the opposite, even to the extreme (bad word i know) that there was probably some leader that was gay and spoke and acted very feminine and probably wanted to go shopping with the girls and look at handbags/shoes. but im talking averages, not particular examples. because there is always en example that bucks the trend. i dont know how to explain it any better than that. so i hope you get it otherwise i would simply say something like 'better to lock the thread'
8. ## men vs woman

im thinking then that when i say society i am actually using the wrong word. sure, there is a place in africa when woman are the top dog, but africa as a whole is the opposite. theres a place in china where woman are top, but china as a whole has men at the top. im talking about the averages overall, not the small pockets that dont fit the norm so when i had this conversation with my daughter, i realized i had to clarify something that i didnt have to with my wife. perhaps i may need to here, but hard in a forum so i will try with an analogy. if i ask who can lift more out of strong fred and weak john, everyone would say strong fred. however if weak john went to the gym everyday and trained real hard then mayby he could then lift more than strong fred, however he is no longer weak john he is now strong john. so the point is still valid that strong fred could lift more than weak john, because weak john had to change from being weak john in order to lift as much. let me know if this analogy makes sense to you. perhaps if you read it again you will see that i claimed woman are/think different, not less capable. my workmates are men. and if they were woman would not have made a difference. i still would have discussed it with them the same . im an adult, and they are adults there is nothing wrong with open philosophical discussion regardless of your gender.
9. ## men vs woman

not sure where you are from. but in my neck of the woods men and woman are very different. can u point out a society where men are not the dominant. i can not think of any. please show me where i claimed men are so much more capable than woman? what difference does the gender of my workmates have to do whether i can type this? hhhmmm. interesting that you have observed the opposite. i guess that just goes to show how different our perceptions are prometheus. i like your detailed response. so if woman have smaller hippocampi that may affect their ability to navigate. this may be a factor in all the main explorers throughout history being me. just an idea? this makes me wonder, are there other physical difference within our brains that may affect the way we think. there are obviously other differences though. hormonal etc that can play a role in our thinking. i agree with your point about sending men into battle. from a physique and breeding point of view. but how about a marcho thing? men would probably think because they are the protectors of their woman it is their duty to go and fight for their woman. society says its the right think to do. a bit like letting woman(and children) off a sinking boat first. (dont get me wrong here im not suggesting we dont do this) so with the workmates discussion last week one example came up. so lets say if a man is trying to reverse a trailer, and a woman is also trying to reverse a trailer. my experience is that the man can reverse the trailer better because a woman will turn be turning the wheel wrong way all the time and gets all confused.. and if a woman is cleaning the house then she can see dirt that the man simply cant see. these are differences in the way we think/calculate etc. but it seems you are suggesting these are learned traits and not a biological thing. but this would imply that both sexes can learn the same thing at the same rate. which i dont think is the case (i have no actual evidence for this though) so, to get a different viewpoint, i also asked my wife and my daughter this same question. they both agreed with me. they both think that the natural differences in woman/man would make a difference in how things are achieved in society. ie, they both think that if a woman has 5 lessons at reversing a trailer, a man may only need 4 lesson to achieve the same result (for example, on average).
10. ## men vs woman

im not sure what topic this goes in so i put it here. so a few work mate were discussing something. id like some input. the world we live in, throughout all of history, has been dominated by men. even from hunter gatherer days until now, in every society, men were calling the shots and woman were put in the "seen but not heard" category. so what if we lived in a world where that was reversed. if the men were "seen but not heard" and woman where in charge and calling all the shots, what would be different. so our discussion was that , i think in the woman world, there is much less chance of things like going to the moon, inventing airplanes, inventing cars, big infrastructure, coming about because a womans brain works much different to mans and for woman to think this stuff up , and implement it, is much harder. a mans brain is more objective, a womans is more subjective. and subjective doesnt get you to the moon, objective does. workmate thinks that whether we are subjective or objective is irrelevant to the big things that humanity has achieved. the objective mind can get you to the moon just as quick, but it would somehow be achieved a different way. a way that in this man dominated world we cant even imagine. who is right?
11. ## Solution to wildfire issues

aussie here. i think the biggest problem is people. the ones that know nothing of the bush putting their 2 bobs worth in. there should be some law that say that politician who live in the cities are exempt from adding their say in parliament regarding country issues. and then the ones that dont bother doing any research. just blurting out what they have seen or heard as if its a fact, when a little bit of research can easily put holes in it. while ever this goes on, we dont stand a chance. and history shows this. after the black Saturday fires the royal commission stated that biggest reason for the fires was lack of winter burning and the best prevention for future fires is winter burning. (yes, it does state that climate is a factor, but a very small factor compare to winter burning) .this has been completely ignored by all governments and even ignored by all the people who think the fires are scomos fault. then theres the people that say that this is the biggest fire in history. when a bit of research can find fires just as big, just as fierce. some of them a hundred years ago. but the difference between those fires and todays fires is how it affects people. more people live in or near the bush, they either cant or wont protect their propety and then when summer comes they wonder why they lost their house. how is their own ignorance toward how much fuel is outside their house scomos fault? i found a local map of my own area. its an official national park map of my local area showing the winter fuel reductions over the past few years. every part of this map is compete bullshit. they state that particular areas were burnt and they give the time burnt. and they are probably using these figures to justify their fuel reduction quota. but as a local i can tell you those places were not burnt at all. ever. until the last few weeks. the places in question used to be state forest. they were selective logged which employed hundreds of timber workers. (which potentially results in fewer timber imports). the logging process was overseen by a local. and the buck stopped with him. there were never any raging wild fires through this area. because if a fire did start, previous back burning and/or access trough fire trails meant the fire could be put out. animals had a chance to escape. until bob car wrecked it he went through and made everything national park. hundreds of people lost their jobs. the place was all locked up. it was never ever burned in winter against locals advice and against what nation parks service stated to their head office. and come this summer the whole lot burnt, meaning the animals had no chance of escape. the people who simply say that the fire are the result of climate change ignore the very basic concept of more fuel equals more fire. they wouldnt smoke at a petrol station so why do they think forest fuel is any different? FIRE HAS NOT CHANGED, PEOPLE HAVE
12. ## brain neurons

lately ive been watching quite a few you tube vids about the brain. i find it fascinating. but theres a few things i wonder and cant seem to find answer on google. are brain neurons the same as the neurons in the rest of the body? or are they slightly different? how? any vid you can point me to. what does a neuron "actually" look like. i cant find any "photos" of them only diagrams and animations ect. every pic i find of them has them as 'like a tree'. so theres the trunk and all the branches. but what about all the space between the branches? what is there? surely inside the brain cant be mostly space as depicted by every picture i can find of a neuron.

14. ## feeling vs facts

on the outside we could see fight or flight as a feeling. but deep in our thoughts we are processing :::::: what are the chances of me surviving if a run/fight, ive only been in 1 fight before and i lost, i have been in 3 races before and i won 2 of them, it has just rained and the ground is muddy/slippery, i twisted my ankle 3 weeks ago.......... all calculations that our brain does instantly without us even noticing. so we label the decision our brain makes a "feeling". but it is in fact very fast calculations hhhmmm. are you suggesting then that feeling dont actually exist but are something that the human mind has put a label on in order to function as more than a purely biological entity.
15. ## feeling vs facts

this could be argued as a calculation
16. ## feeling vs facts

im not sure what section this topic should be in, so feel free to move if necessary. i was discussing a topic with a work mate and wanted some input. also the topic/question may be hard to explain, but here goes. the way our brain works seems to be a mix of of calculations and feelings. we get up in the morning to go to work(calculation) we see on the tv that its snowing outside and get warm clothes(calculation) we go to the toilet (it could be argued this is a biological calculation) we are hungry(calculation) but then we have to choose what to eat (feeling). another scenario we can calculate that by driving faster we are more likely to crash. but then we get a 'feeling' that the traffic ahead is getting heavy, even though we dont notice that we actually observed that, so the calculating mind slows down a little. so my question is, do "feelings" actually exist or are they ALL just calculations in a sub-conscience that we are not even aware that our mind is doing? what we think may be a feeling that the traffic ahead is getting heavy could be the calculations our sub-conscience is doing..... (((3 cars in front brake lights came on for a second. the red car thats beside me that is usually driving faster than me is today going a little slower than me. there seems to be a few extra trucks up ahead than usual.back at the servo i think i saw a mobile crane pull out onto the road as i was going in to get petrol.))))) we could get a "feeling" that we want to go out for a steak,or that we like jenny more than sarah, or a "feeling" that bob is gunna call us asking if we saw his wallet anywhere. but these can be explained but calculations that our sub-conscience is doing. do feelings actually exist?
17. ## Questions to Ask

im not too sure i can see what this thread is about. the construct of 'belief' or the meaning of life/god. but my 2 bobs worth on both it probably doesnt make sense, but me personally i dont like the word 'believe'. it annoys me. i dont understand its function. i dont want to 'believe' something. anything. i would prefer to remain neutral until evidence comes along. when we as humans 'believe' something, and the evidence comes along that our belief was incorrect, we are actually more likely to believe it. this has been shown by numerous studies. so im of the frame of mind to try to remove the human error part. the belief. and just wait until evidence presents itself either way. who knows if there is a god or not. we cant prove it either way. we can be quite sure though that if there is a god, he has not contacted us as the religious teachings we have in the world today are easliy disprovable. so if god is real, then the meaning of life is to be the butt of cruel god jokes. as there is no evidence that he is anything but cruel. if there is no god, then there is no meaning apart from what we make ourselves.
18. ## who is to blame

ive been having a philosophical debate with someone about the concept of who is to blame in an example. imagine a scenario where 2 neighbors have an issue. the neighbors generally get on very well until now. joe is happily washing his car when greg from next door comes strait over and starts screaming at him about a noisy party he supposedly had last weekend. greg kicks the tire of joes car a few times in anger. in retaliation joe starts arcing up and goes over and kicks gregs tire. he misses the tyre and kicks the panel, causing damage. and of course the problem escalates from there. joe could have handled the situation different, but in anger he acted the way he did which resulted in the car damage, which resulted in the problem growing. an analogy i like is " greg made a fire, but instead of joe putting water on the fire, he put petrol" in a situation, who is generally considered at fault. the person who made the fire, or the person who put the petrol.? why/why not?
19. ## shape of concrete drill bits

im a tradie who has spent his life with all kinds of tools. we often take for granted the thought that goes into designing most of these tools. so i was drilling heaps of holes into stone last week. something ive done many times but not really thinking bout it. i tried a different drill bit and was surprised how different it was. so then i got thinking about the science behind drill bit design and how i can learn more about it. after all, knowledge means being able to better choose the right tool for the job. ive tried to find a youtube vid about this but cant. specifically id like to learn,for example, why/how the spirals are different shapes and angles, and the tungsten is different on different stone/concrete bits. can anyone steer me towards a video or something. only really about the tungsten drill bits.
20. ## larger pistons

arc. thanks for the detailed answer. the shorter engine is totally plausible. while the 5.2L 4 cyl is much bigger in size, it is a bit shorter in length. its more cube shaped rather than long like the 6 cyl. not sure bout the turbo spooling up. my isuzu is variable vane turbo which starts spooling up at about 800rpm. my landcruiser has an aftermarket old school turbo that doesnt really spool up till about 1200 rpm. it is however a very low psi turbo which hardly increase the power at all. UD had a truck about 10 years ago, which is almost the same specs as my isuzu, except its a 6cyl instead of a 4 cyl, and it is noticibly more responsive below 1200rpm. i wonder if its something like, less pistons means less rings, which means less end gap. less injectors. less valves. different ratio of heat loss. simpler fuel delivery.
21. ## larger pistons

well, i can tell you that my landcruiser has much more power at low revs than my isuzu. the isuzu lags until it gets to about 1500rpm. the cruiser has power at 600rpm.
22. ## larger pistons

im curios about engine piston sizes and why it is done. i have 2 vehicles. 1 is a toyata landcruiser 4.2 diesel strait 6. its about 25 yrs old. i have recently bought a new isuzu truck with a 5.2 liter 4 cyl. something i wonder is why are the truck makers seeming to go for larger pistons than 20 years ago. so why do isuzu have a 4 cyl motor when a 5.2 liter could easily be a 6 cyl.
23. ## the soul

uuummm, inappropriate how? if you ask me i think the whole "believing" thing is inappropriate in the 21st century. but hey theres still plenty of em here
24. ## the soul

so i was thinking about the "soul" concept and i have a few questions for any people that may believe we have a soul. as i do not. soul believers claim that when we die, the soul leaves the body and goes to heaven, or hell. so, im wondering, when and how did the soul enter the body? was it at birth, or conception, or when. if its at birth, what about a premature birth, or induced somehow. if its at conception, what if the mum has a miscarriage or some other complication. and where is the soul before it enters the body? and how how does gods cataloguing system decide which soul goes to which body? and does every human have one? what about spastics and down syndrome etc. im sure there are humans out there who have less brain capacity than a monkey, do they have a soul? if not, why not. if so, then why wouldnt a more intelligent monkey have one? boy, there are just so many problems with the whole "soul" concept.
25. ## belief

so, if i understand you correctly, maths and science may clash in this scenario. imagine i have 1 million red marbles. i put 1 marble each into 1million small sealed containers. i didnt leave the room so the containers were not tampered with. when im finished i randomly pick up a container and open it. maths says the marble inside is still red. but science says its possible it is now blue. is this correct?
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