# Wrong teachings when I was young **URL:** \ **Category:** The BBQ Pit\ **Created:** [November 21, 2012, 2:19am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673 "2012-11-21T02:19:30Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Scumpup](https://avatars.discourse-cdn.com/v4/letter/s/ce73a5/32.png) [@Scumpup](https://boards.straightdope.com/u/Scumpup)\ **Post date:** [November 21, 2012, 7:24pm UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/41 "2012-11-21T19:24:03Z")
Right here I got ya nuts!/[obligatory guy from New Jersey] ---
**Author:** ![MegaBee](https://avatars.discourse-cdn.com/v4/letter/m/f0a364/32.png) [@MegaBee](https://boards.straightdope.com/u/MegaBee)\ **Post date:** [November 21, 2012, 7:31pm UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/42 "2012-11-21T19:31:14Z")
> [@tdn](#): > > I’m sorry, but if almost everything that we call nuts are not actually nuts, then we must redefine nuts. We just have to keep in mind the the culinary definition of nut is different from the scientific definition. It’s just like a tomato being a fruit by the scientific definition, but most people wouldn’t include it in a fruit salad. ---
**Author:** ![Filbert](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/filbert/32/3433_2.png) [@Filbert](https://boards.straightdope.com/u/Filbert)\ **Post date:** [November 21, 2012, 8:48pm UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/43 "2012-11-21T20:48:04Z")
> [@thelurkinghorror](#): > > Another: daddy long-legs (either the spider or opiliones) is the most. venomous. thing. EVAR. but it has tiny fangs, so you’re safe! Are you saying this is true (which it clearly ain’t) or a myth you were taught at school? I was told at school that the platypus was the only mammal that laid eggs. Fortunately, the teacher actually believed me when I told him about the echidna- that was the only time I got 11 out of 10 on a test 😃 ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [November 21, 2012, 9:12pm UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/44 "2012-11-21T21:12:19Z")
> [@Filbert](#): > > Are you saying this is true (which it clearly ain’t) or a myth you were taught at school? > > I was told at school that the platypus was the only mammal that laid eggs. Fortunately, the teacher actually believed me when I told him about the echidna- that was the only time I got 11 out of 10 on a test 😃 Of course its fake. They were the least scary spiders around. Heard it from somewhere in school. Apparently there is a huge regional divide - where’s I’m from, DDL are harmless spiders. Elsewhere, they are opiliones, harmless non-spider arachnids. I never even saw one of those until I was about 20. On the lawn, no webs in sight. Cool critters. They aren’t even venomous, and their mouth is made for chomping, not injecting. Believing that myth about the spiders is stupid, believing it about opiliones is just ludicrous. It’s always nice to see a teacher who, even if wrong, can know not to be a jerk about it. I taught my 3rd grade teacher about the Seychelles. If you want to go back in time and really nitpick your teacher, 3 genera: platypuses, long-beaked echidnas, and short-beaked echidnas. Three species of the last one, a few subspecies throughout. ---
**Author:** ![steronz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steronz/32/11765_2.png) [@steronz](https://boards.straightdope.com/u/steronz)\ **Post date:** [November 21, 2012, 9:17pm UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/45 "2012-11-21T21:17:08Z")
Airplanes fly because of Bernoulli’s principle. ---
**Author:** ![Soylent\_Juicy](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@Soylent\_Juicy](https://boards.straightdope.com/u/Soylent_Juicy)\ **Post date:** [November 21, 2012, 9:47pm UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/46 "2012-11-21T21:47:10Z")
I swear I remember my Grade 2 teacher telling us that earwigs were so named because they crawl into people’s ears and eat away their brains, causing brain damage and eventual death. In Grade 1 I remember being told that there were these little tiny explosive silver cannisters that bad people had scattered around our school, and if you saw one of these tiny silver things, don’t touch it because merely touching it will cause it to explode and blind you. I remember looking all over the schoolyard for little silver things just to see if they were real or not. 😛 ---
**Author:** ![Kobal2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kobal2/32/20_2.png) [@Kobal2](https://boards.straightdope.com/u/Kobal2)\ **Post date:** [November 21, 2012, 10:00pm UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/47 "2012-11-21T22:00:54Z")
> [@the\_diego](#): > > 1. The longbow doesn’t have a longer range than a winded crossbow. **It’s just shot in a ballistic trajectory while a crossbow is almost always shot line-of-sight**. Actually, this is kind of debated still. For one thing, there is exactly zero reason not to try and fire a crossbow in an arc if a target it beyond straight up range - yes, it’s a difficult shot and the body of the bow kinda gets in the way of aiming, but the same is true of a bow. And yes, one of the main draw (ha!) of the crossbow was that one could hand them over to untrained peasants and expect decent results because they were easy to use ; but professional crossbowmen weren’t exactly rare either back then. Besides, medieval archers didn’t typically fire at targets per se - they fired at a given _range_. If a bowman can learn by rote which angle to fire his bow to hit 300 yards every time, so can a crossbowman. For another, medieval tapestries frequently depict crossbowmen holding their crossbows at an angle, particularly in siege contexts - rather than lean over the crenelations to fire downwards at the people below, they’re more often than not depicted firing upwards. OK, OK, so it’s not exactly photo evidence, I’ll grant you that - but despite the low granularity involved in the medium, medieval tapestries in general tend to be surprisingly accurate and reliable on such details. Which I guess is to be expected when the people who commissioned them fuckin’ were _there_. And have swords. Also short tempers :). I also seem to recall some archeological story about the remains of the besiegees of some castle or other having been found and dug up, and presenting evidence of having been shot with crossbows at a high angle. Which would support the theory that, in that one case at least, the besiegers did just fire straight up and hoped someone would be on the receiving end once gravity remembered to do its thing. Hey, sieges could last years. Gotta keep oneself entertained, amirite ? Can’t seem to be able to dig up the story now though - I might have dreamed that one 😕 Anyway, the point is: not an altogether clear cut historical factoid. Won’t get conclusively cleared up until Apple finally unveils their iTimeMachine app. As for your actual gripe, which is to say the internet backdrafteriffic debate re:English longbow vs. crossbows ; don’t get me fuckin’ started - these people are as bad as the katana brigade 😃 [QUOTE=The\_Sitnam] If that were true there is no reason someone with a crossbow couldn’t tilt it up for greater range. [/QUOTE] Can you think of any ? Food for thought: modern snipers also “tilt up” at extreme ranges to compensate for bullet drop. So it works with a bow, and it works with a rifle, but it doesn’t/shouldn’t work with a crossbow because… ? [QUOTE=the\_diego] at crecy, deprived of their pavises for protection, the genoese could shoot neither far enough nor fast enough to counter the english long bows. [/QUOTE] Additional factors involved: the English bowmen were up on a hill (boosting their range), in hastily dug-up defensive works (i.e. semi-decent cover), and it had been raining on both armies for days before the battle started. Which didn’t matter too much for the English bowmen (who kept their bows unstrung outside of battle) but was bad news for the Genoese because re-stringing an arbalest in the field is a bitch and a half, so they typically marched with their bows strung. Wet strings don’t work too well. But yeah, granted, the biggest :palmface: still has to be the French commanders ordering them forwards without waiting on the pavises, and expecting the usual performance. Officers, man ! Incompetent arseholes from day one :p. ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [November 21, 2012, 10:04pm UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/48 "2012-11-21T22:04:24Z")
> [@Trinopus](#): > > Has anyone ever actually done the experiment of putting a weight on glass and seeing if it “flows?” My old teachers said that this would happen, including the glass flowing “around” and encircling the head of a nail, if weight were put upon it. Not glass, but a professor in Australia set up an [experiment](http://en.wikipedia.org/wiki/Pitch_drop_experiment) with pitch in 1927. He heated some pitch and poured it into a funnel, let it settle and cool, then removed the seal from the bottom of the funnel allowing the pitch to flow out of it. The eighth drop fell in November of 2000; the ninth drop is expected soon. The funnel appears to be made out of glass, so make of that what you will. ---
**Author:** ![Malthus](https://avatars.discourse-cdn.com/v4/letter/m/85f322/32.png) [@Malthus](https://boards.straightdope.com/u/Malthus)\ **Post date:** [November 21, 2012, 10:43pm UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/49 "2012-11-21T22:43:39Z")
> [@Sailboat](#): > > Eh, range isn’t everything. As **Sitnam** indicated, crossbows typically have a shorter draw length, which means that for the same draw weight (force), they produce less _impulse_ but more _force_. Since impulse tends to stabilize a projectile, that means they are slightly less accurate at longer ranges. > > A greater detriment to their accuracy comes from the fact that arrows are typically longer than crossbow bolts. The longer distance between the projectile’s balance point and the vanes/fletching gives more leverage to the aerodynamic forces stabilizing the projectile. Net result, crossbow bolts tend to precess at longer ranges and lose accuracy. > > However, the two main reasons they were inferior in the press of battle are, as several posters mentioned, their much lower rate of fire, but also the fact that tyhe horizontal orientation of the bowlimbs means you can pack fewer crossbowmen into the same frontage of the line of battle. Once you can pack _significantly_ more archers into a line of battle AND they _each_ fire _several times_ faster, everything less pales in comparative effect. Heh it would make an interesting analysis as to why crossbows never really “caught on” in popularity compared with early firearms. They both shared the advantage that they were far easier to use than longbows, and they both had the same drawback of low rate of fire. In terms of expense, gunpowder was always very expensive to make and a bitch to store and distribute. Not only that, misfires, accidental explosions, etc. made using the things risky. It is easy to see why armies rejected longbows - as being too expensive to train soldiers to use effectively. Even if it’s a better weapon, if you can’t actually get enough longbowmen, that fact does you no good. So why did early modern armies choose early firearms over crossbows? ---
**Author:** ![digs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/digs/32/14889_2.png) [@digs](https://boards.straightdope.com/u/digs)\ **Post date:** [November 21, 2012, 10:45pm UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/50 "2012-11-21T22:45:40Z")
My HS chemistry teacher called glass a liquid, and cited old windows thicker at the bottom. The other (older, more crotchety) chemistry teacher snuck in behind him as he was explaining this… and dropped a pane of glass. As it shattered, he yelled “So THAT’S a liquid?” ---
**Author:** ![Sattua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sattua/32/11906_2.png) [@Sattua](https://boards.straightdope.com/u/Sattua)\ **Post date:** [November 22, 2012, 12:03am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/51 "2012-11-22T00:03:37Z")
No, high school health teacher, multiple personality disorder is not the same as schizophrenia. ---
**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\ **Post date:** [November 22, 2012, 12:24am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/52 "2012-11-22T00:24:32Z")
> [@steronz](#): > > Airplanes fly because of Bernoulli’s principle. Um… That is debated by many, but it is, in fact, still true. Airplanes could fly with flat boards or planks for wings, but they’d require much greater engine-power. The airfoil shape of the wing increases lift, making the current thrust-to-weight ratio of engines sufficient. You can actually test this yourself by having a friend drive you in a car, while you stick variously-shaped wing-like objects out the passenger window. (Not on the public highways, please!) A flat plank will, in fact, produce some lift…but an airfoil will produce much more lift. ---
**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\ **Post date:** [November 22, 2012, 12:28am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/53 "2012-11-22T00:28:26Z")
> [@digs](#): > > My HS chemistry teacher called glass a liquid, and cited old windows thicker at the bottom. > > The other (older, more crotchety) chemistry teacher snuck in behind him as he was explaining this… and dropped a pane of glass. As it shattered, he yelled “So THAT’S a liquid?” Funny, but fallacious. You can “break” a stream of thick liquid. Where, exactly, on the spectrum of thickness does a liquid become some other form of matter? Is there a “fourth” form of matter, such as a gel, that is, formally, neither solid nor liquid? ---
**Author:** ![steronz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steronz/32/11765_2.png) [@steronz](https://boards.straightdope.com/u/steronz)\ **Post date:** [November 22, 2012, 12:43am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/54 "2012-11-22T00:43:26Z")
> [@Trinopus](#): > > Um… That is debated by many, but it is, in fact, still true. Airplanes could fly with flat boards or planks for wings, but they’d require much greater engine-power. The airfoil shape of the wing increases lift, making the current thrust-to-weight ratio of engines sufficient. My understanding is that the shape of the airfoils decreases _drag_, making the current thrust to weight ratio of engines sufficient. All I know is that “the air on top has to move faster so it’s lower pressure and that’s where the lift comes from” is really know true. It may play a small role, but it’s mostly angle of attack combined with efforts to reduce drag. ---
**Author:** ![the\_diego](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@the\_diego](https://boards.straightdope.com/u/the_diego)\ **Post date:** [November 22, 2012, 1:16am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/55 "2012-11-22T01:16:37Z")
> [@Malthus](#): > > So why did early modern armies choose early firearms over crossbows? Some books said the musket gradually gained favor. The Swiss halberdeers had crossbowmen in their ranks. Musashi said unequivocally that the musket was best for defending a castle. Aside from ease of mastery, the musket can out-range both bow and crossbow. ---
**Author:** ![drewtwo99](https://avatars.discourse-cdn.com/v4/letter/d/d07c76/32.png) [@drewtwo99](https://boards.straightdope.com/u/drewtwo99)\ **Post date:** [November 22, 2012, 1:37am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/56 "2012-11-22T01:37:30Z")
> [@steronz](#): > > My understanding is that the shape of the airfoils decreases _drag_, making the current thrust to weight ratio of engines sufficient. All I know is that “the air on top has to move faster so it’s lower pressure and that’s where the lift comes from” is really know true. It may play a small role, but it’s mostly angle of attack combined with efforts to reduce drag. You are correct in the assertion that the equal-time-transit “theory” is flat out wrong. But, there is an area of lower pressure above the wing and higher pressure below the wing, which may or may not exist without the airfoil shape. In the end, Newton’s laws have to hold, so if you want to just think of it as the force of lift up on the plane is equal to force down on the air, so essentially an airplane is an efficient way of pushing air downward, that’s not wrong. But obviously the engineering is more complicated than that. ---
**Author:** ![the\_diego](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@the\_diego](https://boards.straightdope.com/u/the_diego)\ **Post date:** [November 22, 2012, 1:49am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/57 "2012-11-22T01:49:25Z")
None of my teachers and relatives could tell me how fixed-wing aircraft maneuver, aside from James Cagny or George Peppard operating control sticks. I had to read up on ailerons and tabs and rudders. They were also at a loss as to how a plane could ‘brake’ in mid-air. ---
**Author:** ![Kobal2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kobal2/32/20_2.png) [@Kobal2](https://boards.straightdope.com/u/Kobal2)\ **Post date:** [November 22, 2012, 1:57am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/58 "2012-11-22T01:57:03Z")
> [@Malthus](#): > > Heh it would make an interesting analysis as to why crossbows never really “caught on” in popularity compared with early firearms. Never caught on ? Besides the English (who stuck with longbows for some reason), all of Christendom loved themselves some crossbows for over 5 centuries - although nowhere near as much as in Italy, Spain and proto-Germany. Even so, it took about two centuries for firearms to really take over, from the early comical hand-cannons to the first reliable arquebus and muskets. As for why they did take over: they punched through armour quite a bit better (which became even more important as metallurgy & armouring techniques steadily improved), shot farther (if a bit… erratically, but that could be remedied by shooting moar of them :)), were less unwieldy (particularly in mixed formations with pikemen), the smoke and noise were a plus against cavalry as well, and once the first firing drills\* were invented to remedy the ROF issue, well, it was all over but the shootin’. - you’ve seen those I’m sure - first rank fires, turns about, becomes the last rank, second rank fires etc… ---
**Author:** ![the\_diego](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@the\_diego](https://boards.straightdope.com/u/the_diego)\ **Post date:** [November 22, 2012, 2:55am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/59 "2012-11-22T02:55:53Z")
Crossbows are about as difficult and expensive to make as muskets. The lock and trigger mechanism are more solidly built. Steel bows have to be well-forged and tempered. Both crossbow and longbow lost much of their legend after the second Anglo-French battle when the French hired Genoese mercenaries, this time fully armored knights. Whereas a longbow bodkin can pierce chainmail at 100 meters or farther, they can’t punch through tempered plate armor even at 40 meters. The English won that battle through foot-fighting but their archers were massacred by roughshod knights. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [November 22, 2012, 3:46am UTC](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673/60 "2012-11-22T03:46:46Z")
Oh! 'Tis the season and all. I was taught that poinsettias were deadly poisonous. And keep it away from your cats. Never dogs for some reason, maybe because cats jump, but cats aren’t known for gobbling food first and asking questions later like dogs were. It might be related to toxic plants, but that doesn’t mean poinsettia’s the same. [Previous page](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673.md?page=2) [Next page](https://boards.straightdope.com/t/wrong-teachings-when-i-was-young/641673.md?page=4)