*In short:* The flexing of the arrow is *not* the archer's paradox. The archer's paradox is the perception that the arrow must go through the point of origin in order to hit the target. In other words, the arrow must follow the bow plane (i.e. the string's path) to fly straight to the target. However, when nocked, the arrow points *away* from the target. The arrow must therefore go around the bow in order to enter its intended path. Because of the offset from the bow plane (i.e. the arrow does not follow straight along where the string should go), a sideways force is induced. The back of the arrow experiences a compression force, and as the arrow shaft is not rigid, this causes the arrow to oscillate. The timing of this is oscillation is what allows the arrow to go around the bow without being deflected. The archer's paradox is not compensated by the archer aiming off, but by the selection of the right spine (i.e. the flexibility of the shaft) so that for a given bow of a given draw weight, the forces that act on the arrow result in the right amount of flex. Too little, or too much spine, and the arrow will fail to clear the bow, resulting in the arrow being deflected to one side or the other. There are two causes for the misunderstanding: 1) Most bows today are designed to be shot close to or past centre, hence the "window" in the bow, allowing for more direct alignment, as compared to traditional bows which were not made with this design. 2) The incorrect identification of the flexing arrow in slow-motion videos because it looks epic, though if you pay attention to the narration they usually do explain why this happens. *It's basic trigonometry* Except that basic trigonometry doesn't explain why the arrow flies towards the direction of the bow plane rather than along the line of the arrow. The arrow does not travel towards the direction it was pointing at while at brace.
You are so going to have all the experts telling you that you are wrong. Archery 101 has two videos explaining this and they came out in comments with their engineering degrees saying the paradox was the fact the arrow appears to go through the riser, or that the spine was the paradox.
@@incorporeal3793 Thats what I always thought. That even though the arrow is pointing off target at full draw, the arrow flexes around the riser and travels in line with the string and the middle of the riser to hit the bullseye, hence appering to travel through the riser. Therefore even though the arrow is pointing to the left (or right depending), it still flies straight, hence the paradox. Now l don't know what's right or wrong anymore. It feels like my whole life is a lie.
Nu sensei i practice with my bow by my self and when i shot i use it inclinated to the right so i can aim better with the arrows tip is this wrong o affects the accuaracy in some way? Thank you for your time and the paradox video :)
@@incorporeal3793 i asked about these engineres ,no reply and not once was en.wikipedia.org/wiki/Euler%E2%80%93Bernoulli_beam_theory mentioned neither was hooke en.wikipedia.org/wiki/Hooke%27s_law or newton . not a mention that the archers paradox was an invented terminology , a simplification
@@mortenjacobsen5673 Here is a scientific breakdown of it, sorry no Illustrations. This is from 1910 btw. The Toxopholist's Paradox By E. J. RENDTORFF A PARADOX is a statement of fact apparently opposed to common sense. Why is it that an arrow will fly along its aimed course instead of several degrees toward the left, when it is held on the side of the bow with the string pushing it further to the left as the nock approaches the bow ? The fact that it does fly true, instead of shifting radically off its course, as we would naturally expect, constitutes the toxopholist's paradox. Ford, Butt and Walrond have explained this phenomenon to us, and for several decades their ideas have been accepted and passed unchallenged. It takes some little nerve for a novice to stale publicly his unbelief in the classical explanation. In order to explain my heresy I shall attempt to discuss the various phenomena that enter, give my conclusions, and then let our archery friends act as the jury. Figure 1 represents an arrow full drawn and ready for release. The center of gravity of the arrow is at G. On release the force F exerted through the agency of the string moves the arrow forward. The arrow starts from rest and accelerates in velocity until it leaves the string, after which it travels with a uniform velocity, except as it is slowed up by the friction of the air. Now, everybody at rest has a tendency to remain at rest. This tendency is called inertia. The existence and action of inertia can be illustrated as follows: Attach two strings with a breaking strength of about eleven pounds to the top and bottom of a ten-pound weight. Suspend the weight from one string, with the other one hanging loosely below. A slowly acting force of but one pound exerted on the lower string will suffice to break the upper one; but if the lower string be jerked rapidly the weight will remain hanging while the lower string breaks. Effect 1. When the arrow is released and the bow string moves forward, the angle D N G constantly increases. This gives the center of gravity an accelerated motion toward the left. The inertia of the arrow thus produces the force C, which tends to prevent the angular displacement. This force C becomes constantly greater until the arrow leaves the string, because, first, the arrow accelerates in velocity; and second, the angle of displacement constantly increases. The force C produces the two balancing forces B against the bow, and A against the string. While the center of gravity lies within the bow, the force C will produce a slight bending of the arrow, with the concave side toward the left. It is the force B which prevents the arrow from falling away from the bow, and not a problematical twisting of the string, as some of our English authorities have stated. In Figure 2 are illustrated the conditions applying when the center of gravity of the arrow has passed the bow. The forces C and B remain in direction as before, but they have increased in magnitude. The force A is zero when G is opposite the bow, and then changes in direction and increases in magnitude until the nock leaves the string. The force C now bends the arrow toward its aimed course, with the concave side of the flexure toward the right. This corresponds exactly with the statements of Walrond, Ford and Butt, with the following exceptions: They do not mention the forces A and C, but assume the existence of B only (which Ford calls a blow) and ascribe to it the various bendings of »the arrow. Now. as the force B always pushes the arrow directly against the bow, no turning moment can exist and the force is therefore not operative in any of the motions of the arrow as described. Effect 2. They also mention the effect of the feathers throwing the nock to the left, as the feathers pass the bow, thus helping the alignment of the shaft. Giving our English friends full credit for the two reasons so far deduced, let us proceed with our inquiry. The force A increases as the string approaches the bow. When the nock leaves the string, with the customary clearance of about 7 inches, the force C would be about 10 inches beyond the bow for my 29-inch arrows. The equation for equilibrium would be A x NE = C x GE At this moment the angle D N G is increasing at its most rapid rate, while the velocity of the arrow has reached its greatest value. In other words, the force C is now at its maximum value, while the force A is 10/7 times larger than C. What happens? Effect 3. The force A moves the bow string toward the left, thus relieving the bending of the arrow and decreasing the shifting of the arrow out of its aimed course. These three effects are operative, but are they sufficient to explain the paradox? If they were sufficient it would follow that a bow held rigidly in a frame, with the arrow released either by hand or by some trigger contrivance, would project the arrow at least as well as when shot by an archer. Let us see what Dr. Elmer has to say about the subject. I shall quote from a recent letter: "What do you think of a mechanical support and trigger for a bow as a method for testing arrows? I made one and it gave results that were very surprising. For instance, the arrows flew rather wild and showed a very marked tendency to buckle. What astonished me still more was that they veered off to the left. This made it seem likely that ordinarily the bow is slightly pushed to the right by the arrow." Although we have already added one new reason to those formerly accepted as sufficient, we are apparently not yet entirely on the correct track, so let us continue the study of our force diagram. Effect 4. From the instant the center of gravity of the arrow leaves the inside of the bow until the nock leaves the string, the force A offers a considerable turning moment, tending to turn the plane of the string and bow toward the left. The magnitude of this turning moment is the product of the force A multiplied by the distance N E. The distance N E varies from 17 to 7 inches, but as it decreases, the force A increases, so that the turning moment remains fairly constant and of considerable magnitude. In Dr. Elmer's machine the bow cannot turn, but in the archer's hand it can and does.If not properly controlled it will move the bowstring against the arm guard. Effect 5. When the arrow is drawn the left arm is under considerable strain and the hand moves slightly to the right. On release, the removal of the constraining force moves the arm somewhat to the left. The muscles do not respond at once, due first to the inertia of the arm and, second, to the fact that muscular movement does not begin until a certain time after stimulation. As the arrow remains in con tact with the string for about 1/40 of a second, after release, the motion of the arm toward the left is probably negligible until after the center of gravity of the arrow has passed the inside of the bow and then increases in magnitude until the arrow leaves the bow. This would have the tendency of moving the nock toward the left, thus pushing the arrow back parallel to its aimed course. This last effect cannot be proved through the use of mathematics as it depends upon several variable factors than cannot readily be determined, such as the exact period when the muscular recoil is operative. I derived the conclusions mainly though a prior reasoning. The following facts seem to prove the conclusion correct. When the nock leaves the string the force A no longer acts against the arrow. This would greatly diminish the force B and consequently produce but little wear on the shaft along the last seven inches of the nock end. My old arrows show considerable wear in this zone, which leads one to believe that the fifth effect is operative to a marked extent. In addition to this, arrows when shot buckle far less than they would if effect 1 were the main factor. The first three effects are operative in a mechanical contrivance, such as that used by Dr. Elmer. The fact that this machine shoots badly to the left and buckles the arrows, as it theoretically must, shows that the last two effects are not only operative but are probably the chief factors in the solution of the problem. The relative magnitude of the various effects depends somewhat upon the personal equation of the archer, when he, through intuition, gets the five effects balanced he is able to shoot without lateral displacement, or undue buckling of the arrows. I believe we are now prepared to solve the problem, discussed in a previous article, pertaining to the effect of a variable point of balance of our arrows. A variable position of the center of gravity alters the relative magnitudes of Effects I, 3, and 4. As just mentioned, an archer shoots without lateral displacement when all five effects are properly balanced. A difference in the position of the center of gravity of our arrows changes the relative magnitude of three of the effects, so that an exact balance of all five effects cannot be maintained, unless the point of balance of each separate arrow corresponds closely to the remaining arrows of the set.
There are so many video's about the archers paradox here on youtube, 90% of them are wrong and the rest are so confusing that most viewers in the end stil don't know what the actual paradox is. There are 2 archers. Archer A and archer B Archer A has a modern hunting bow that is cut to center. If he aims, his arrow, his string, and his bow are in 1 line with the target. When releasing the string his arrow wil hit the target. This is logical. Archer B has a traditional longbow with no shelf. If he aims, his arrow, his string, and his bow wil NOT be in 1 line with the target, EVEN at full draw. When releasing the string his arrow wil also hit the target. This does not seems logical, and thats the "archers" paradox.
@@karlgunther-turkisharchery4272 the flight of the arrow is decided at the nano second of release as the front node of the arrow pushes of the riser for khatra to work you need to be insanly faster than human reaction time of 0.3 second at best or faster than the arrow , or the arrow has the right spine so the clearance is good with or without khatra
Good explanation but one point of clarification needs to be made, imo. The arrow doesn't correct itself by it's own volition (of course) nor is it caused by the string rolling off the fingers. If that were the case then arrows fired from a bow using a release aid wouldn't flex. Even crossbow bolts flex, albeit very little in relation to arrows. The flex is down to physics, specifically Newton's first law: an object at rest tends to stay at rest until acted upon by some external force. In this case the arrow is the object and the string is the external force but it is important to remember that the force acts upon the nock and the nock then acts upon the shaft which, in turn, acts upon the point. So what happens is that the force travels *through* the arrow while the point is remaining at rest. *This* is what causes the flex.
Yes Sir, you explain it correctly. Flexing = Mass Inertia of the arrow Point + Internal Force that travel through the Arrow Shaft. Btw, Internal Force would have similar Newton with the DRAWN STRING force.
You're right, he says in the video that the arrow bends to get around the bow, but it doesn't. It bends because the nock starts moving before the point does.
@@vodoopupped9687 yes it is. The paradox is "hey, the arrow is pointing to the side not straight at the target, but it still goes straight to the target even if it's pointed to the side. Weird, it's a paradox". The solution is that the flexing allows it to get around the bow and into the target.
@@vodoopupped9687 considering you're telling us we are wrong while also saying the same thing we are saying, yeah you don't understand what you are reading.
@@vodoopupped9687 it's astoniajing how little reading comprehension someone can have. Now please, let's stop this conversation before you give me an aneurism.
This is an excellent explanation of archer’s paradox. I own 3 English Warbows, as well as a number of modern traditional recurve and long bows with the cut out shelf for the arrow. This lesson helps me to better understand how the arrow travels to the target. I really never understood the concept until now. Thank you for another exceptional lesson!
I was really excited the first half of the clip because I thought I have FINALLY found the one clip on youtube that explains the Archers paradox correctly! Then I was disappointed when you got to the actual paradox which is a shame, because everything else is correct, and in my opinion the best video I have seen that explains how the paradox is *not* really about bending arrows. As you said: a paradox is a contradiction that seems to defy logic. However, the fact that the arrow changes its angle to the target as you draw it back does *not* contradict normal intuition. That is just basic trigonometry. It is nothing surprising that contradicts intuitive logic. So that is not the paradox. The paradox *is* the fact that the arrow will fly in the direction it has at full draw even though logic tells us that the arrow must pass through the position at brace height as it travels forwards, and at this position it points off target, so it shouldn't fly straight towards the target. *This* is the paradoxical part that contradicts intuitive logic. The slowmo shots of the bending arrows show us how the arrow can clear the handle without being deflected, so in other words, why this apparent paradox isn't an actual physical paradox. If you could re edit a minute or so in the middle of the clip I would be so happy. I have commented on this subject on one of the other big archery channels where the channel owner had made a poor attempt at "clearing up the confusion" and he basically just responded aggressively and removed my comments.
"he basically just responded aggressively and removed my comments" - Maybe I removed your because you resorted to name calling? Funny how you left that part out. "If you could re edit a minute or so in the middle of the clip I would be so happy." - wow, that is an arrogant request.
@@3DArchery The comments are not there anymore so we can't really go back and check can we? But no, I was nothing but civil. The other person who actually started the thread and agreed with me got fed up though...
I think your explanation is better, however the arrows trajectory will depend highly on the spine of the arrow. So perhaps, to satisfy everyone's misconceptions the paradox might be more along the lines of: the arrow might not hit any of the geometrically centered points between full draw and brace height, based on its spine.
Thank you for making a post that was exactly what I was going to say before I said it. If you could edit the comment so that nothing after “… actual physical paradox.” was included, it would make me so happy! Then the useful parts of the comment would be there without all the drama. Maybe this thread could disappear too.
It's a very good video that explains it clearly. It's also the video that people don't pay attention to, as many viewers get tunnel-vision on the slo-mo flex and then try to backsplain using that snippet.
Great video as always! I just got my Nika Black Phoenix in this week. I sanded down the handle a little but I love it! Thanks for the review you did on it!
NUSensei, very good explanation. Greg from 3D Archery did one also and was very well done. Some will get it some won't want to and you will not be able to change their minds. Thank you.
excellent explanation and easy to understand. Additionally, I am of the position that some of the flexing of the arrow is the result of the stored potential energy in the bow being converted into kinetic energy. The arrow goes from "full stop" to "full speed" and the flex is the result of inertia and the energy transfer.
This is how the paradox works. The back of the arrow is being accelerated by the arrow, while the front of the arrow is inert.Because the string is moving along a different plane, the back of the arrow is forced along that plane instead of where the arrow is pointing. This is what causes the arrow to flex, and the spine of the arrow allows it to clear the bow as it oscillates because of this initial flex.
Seen a lot of archers paradox videos. Like this one the best. Think it comes closest to my idea of the paradox which is, simply stated, that in order to hit a target in front of you you have to start with the arrow pointed away from the target. The rest of the videos deal mainly with why this works; i.e. arrow spine, how close to center the riser is cut, etc.
Here's my take: The flexing will happen however the arrow is released, the spine of the arrow is not enough to prevent column buckling due to launch forces (except for a crossbow bolt where flexing would be bad). The spine has to be enough to prevent excessive buckling (which can break the arrow and reduce accuracy). Finger release (and nock height) will ensure the initial flex direction is consistent, which I think ensures the fletching should clear the arrow rest - some high speed photography would be good to see on this for modern bow and various settings and release methods.
Hey Nu, can you do a video about arrow spine as you already talked a bit about it in here? How much spine is good for how much poundage, what does it affect? Thank you :)
All this for historical bow would be most obvious from above. Then we could see the line running from the tip of the arrow straight to the target centre, while the continuation of the shaft would be another line, which goes at the angle from the first one away from the centre of the target to the left (for the right hand archer).
The part that is the actual paradox seems like simple geometry: Consider three points, the bow (X) the string (Y) and the rest of the arrow (Z). At brace, angle XYZ should be a much bigger measure than angle XYZ at full draw. Adding point W, the target, in line with X and Y, you can easily figure that the angle between the target and the rest (with the string as a vertex) will be bigger at brace than full draw. Hopefully this clears it up for someone
I'm so happy that my decades long campaign of educating people about what "archers paradox" actually is, causes so much angst with people who think it's about arrows bending.
My understanding is that the Archers Paradox is : How can the archer shoot straight when the bow is in the way of the line between the string and the bow centre? As you rightly point out, when the arrow is pulled back its angle of deviation from the bow/string plane lessens. So when you fire an arrow it's angle of deviation from the bow/string plane increases as the string pushes it forward.This causes the arrow to press against the bow, and induces the oscillations in the arrow. The first oscillation in the arrow, curves the arrow slightly around the bow, and the arrow continues to oscillate on its way to the target. I hope that makes sense.
Hi NuSensei. Good video and nice explanation about "archer paradox". However, the arrow flexing is not only consequence of finger realesed (as it seems in your explanation). The energy stored in the limbs in full draw, released suddenly, is the main reason for the arrow to flex.
Ok when I heard you saying that this wobbling is the result of the paradox i was like: "what!? wtf!?" and just when I started writing that this paradox is not at all about how the arrow fly but about the arrow hitting the target when logicly it shoudn't ever reach any target at all, I looked for it on google. Turns out this actually is the archer paradox and what I was thinking about is the arrow paradox :D Every day you learn new things I guess...
Its all the transfer of energy from the bow to the arrow. starting with string vibrations and its movement back toward the center of the bow. as well as finger release, causing increase vibration or string movement to the right or left, friction from the rest, as well as how long the rest holds the arrow, (the longer the more level will stay,but increases friction). It seems to me that ''silencing'' cutting down on friction and a longer rest that is adjustable is essential for the shortcomings of the re-curve. Finally if your string, rest and arrow don't line up its going to hit the side of the riser, and if you release and move the bow it affects the direction. ( making it go left at high spine rating as a result of the rest not being at the dead center of the bow, and flex and move left at lower spine ratings). I guess thats why ppl use dampeners, balances, and adjustable rests.
So, for someone like me, who wants to start in archery, as a right handed that wants to use a bow with the cutout on the right side (it just feels better that way for me), the only way for me to shoot the bow properly, is to use a thumb draw. for a three (or two) finger draw, the cutout must be on the left side of the bow. love your videos btw!
There IS a paradox where you do sort of get loss of power because of the flex, a second archer's paradox if you will. It's utterly irrelevant for target shooting, but it's there. The idea here is that the same arrow fired from the same bow at same draw length has more effect on target at 10 meters than at 5 meters, which is counterintuitive. The mechanics are pretty easy to understand - because arrow shot from a traditional bow is flexing and tilting, it will not hit directly, i.e. with its entire mass behind the point, pointed in one direction. (Flexing dies waste energy, but that alone doesn't create a paradox, just lessens the total joules available). Just about the only place you can notice this is when you are shooting at thin, hard material that is close to what the given bow can penetrate. Thing is, that is pretty much the definition of armor, so you can get a strange situation in testing bows against metal armor, where the armor mostly stops arrows at short distances, but is penetrated at longer ones. One additional thing to remember is that armor doesn't have to stop the arrow, just deflect it, and that's far easier to do when the hit comes in at an angle. This gets more and more pronounced if you use a heavy bow with wodden arrows with straight shafts - the historical ones were barrell-shaped. This paradox disappears very shortly, and after about 10-20 meters, arrows behave the way you'd expect them to. So, paradox is that effect on target doesn't look like 6-5-4-3-2-1, but as 3-4-5-4-3-2-1
The paradox is shooting around the bow. Meaning how you showed at brace the the arrow flys it should go the direction it points when it comes back to brace flying off to one side because of the bow being directly in the path of the arrow. But instead because of the tolerance of the arrow it bends with the pressure of the release of the string causing it to bend and curve around the bow and go straight
To make it barely simple, where your arrow shaft points at full draw is different from where your arrow shaft points at no draw. This is the part of archer's paradox that everyone agrees. However, where your arrow flys to after leaving your bow depends on the combination of all factors: draw weight, draw length, spine stiffness, arrow head weight, and even your finger's subtle deviation on releasing. Even the spine chart for selecting your arrows may not be always right. For me, I have a 22lbs PSE snake. I have to use 340 and 400 spine carbon arrows to make it fly to where I point my arrow at full draw. If I use 600 spine arrows or even fiberglass arrows that I selected by spine chart and bought, all fly to the left. So key discussion in this video is the difference of your arrow shaft pointing to at full draw and at no draw. Where your arrows fly to when leaving your bow depends on everything combined.
That's the part that is wrong, that's not a paradox, that's trigonometry. Your arrow ISN'T supposed to fly in the direction it's pointing at full draw, it's supposed to fly in line with the force of the string, which happens to be through the bow. But, as with most things, if it works for you, keep doin' it.
The other thing to remember is that the arrow is a projectile, not a rocket. It doesn't fly where it is pointed. Due to the fletchings, it points where it flies. The string always pushed the arrow in the direction that the bow is pointed, so the arrow flies in that direction but points in another direction momentarily. Since the arrow is not a rocket, there is no force pushing the arrow in the direction that the arrow is pointing. The Law of Conservation of Momentum demands that the arrow fly in the direction that the string pushes. There is no physical law that demands the arrow fly in the direction that it is pointing.
huh! I learned something today. I thought the "paradox" was that at a certain point adding energy (a higher draw weight) would not result in the arrow going faster because it would start to flex more as the string accelerates it and therefore may even travel slower through the air due to the increased aerodynamic drag.
Arrow (whispers to archer): 'After 5000 years of this paradox crap, isn't it time the bow got out of the way?' Bow: 'Noooooooooooooo!!!' And that ladies and gentlemen, is how the mutant centre cut bow was born
I do not have my bow yet as it is (or so I have been informed) now in the post, I have been stressing over this spine issue and struggling to understand why it matters so much with compounds which are all (or all the ones i have checked out) centre shot bows.. I understood the paradox long ago, long before developing a serious interest in archery, and my gut feeling was the only major issue with spine and a compound is that too week a spine could end up breaking under to force of a heavy bow.. After watching your vid It would appear that my gut was right, to a point at least.. I must say also that I find your instruction style and video presence superbly informative and engaging, many thanks for sharing your passion and knowledge ;)
Now we just need a bow with a magnetic levitating window which suspends the arrow magnetically, and upon release, sensors monitor the flex and trajectory to actively correct the arrow as it leaves the bow.
Talking about the fletching limiting the movements, I shoot compound. When we are setting up our arrow drops and tuning our bows, we test shoot arrows without fletching to insure our arrows are being released with neutral forces.
then why put thatching on and what are you actually testing ?how it flies without thatching , but your gona use fleatchings.... i call it lunacy others bare shaft tuning. feel free to explain
@@mortenjacobsen5673 You're checking your centers on your drop away or arrow rest and if you have a bow with two cams, if they are in sync with one another. A fletched arrow will tell you you're off but it might not tell you which way. As it'll correct its self go through your paper target looking as if it was off the other direction. A non fletched arrow will exaggerate what's happening. This becomes more important if you plan on using broadheads that counter to self centering effects of fletchings. (Not all states allow mechanical broadheads that stay shut in flight)
@@michaelt6413 then you canjust tune the fleatched arrow the tear will tell you but just the exit flight ,cam sync I do by fell and visual since the d loop can cause tears too and effectnock travel . i could never get the drop away to fall fast enough so went fo ra blade
That is absolutely NOT the archer paradox, that's math, the archers paradox is however, that the arrow (with the correct spine) will travel in the direction of the string instead of the direction it's pointing, even though that path is being blocked by the bow. SmarterEveryDay has an amazing video on it, and the first 3 minutes explain it really well. What was said in this video at around 7:50 is the archers paradox.
It looks like because of your elbow hinge as you draw, the hand travels back at an angle, but then straightens up (in relation to the target) as you find your anchor...
The fact that the arrow flies to where the center of the bow points rather than where the end of the arrow points - sounds paradoxal to me. While the fact that arrow angle changes when you draw - does not.
The flex is also the result of sudden acceleration of the arrow isn't it? That's why center-shot compound shooters still have to factor in arrow spine.
Khatra is not necessarily for clearance AFAIK.. It can be depending on tradition, but from my experience it's mostly a sort of follow-through, but for your bowhand. Perhaps not quite the same, but olympic archers sometimes let their bows swing forward after a shot, kinda like that. Great video as always, keep it up!!
@@karlgunther-turkisharchery4272 depends on the archer and the style but the bow should drop cause of the lose grip and ex ess force forward as a result of less torque and good alignment and some doit as a useless flurry . unless you know all archers you are making assumptions and arguments from ignorance . and bytw i dont drop my bow caus i dont use the bow hand release technique ..some could say its a version of khatra but then you need a clear definitiv of khatra
@@mortenjacobsen5673 ua-cam.com/video/8whS-iFAJsI/v-deo.html Says all, what I think about it. But I don't no anything about modern olympic archery, I only was tought how, why and when to perform khatra....
Nu. That's fun. The comment fight has begun. The word knives are out. The punctuation arrows wiggling through the air. And I can't resist adding bad humour. Butt in my defence. I shoot for fun not physical fitness. Oh wait that's physics, oops. Cheers mate
What is the "archer's paradox"? The term "archer's paradox" was coined because it was at the time not understood how an arrow could be aimed directly at the mark at full draw, yet be offline at brace height and upon returning to departure, but still recover and go where it had been pointed at full draw. This was the paradox. Many, if not most of the illustrations which accompany this definition all too often have a tendency to add to the confusion by not usefully representing what really happens. The most commonly quoted and misleading definition of paradox is that "the arrow bends around the bow and recovers to go where the bow is pointing". This definition is not useful since it is more obviously natural and efficient to point the arrow at full draw directly at the target. This done, it is of no interest to the archer where the bow might be pointing, since it is not about to go anywhere. But this presumes that we match our shafts with this in mind: that it should go where it has been pointed at full draw.
When you’ve been shooting long enough to know what people mean when you hear them using paradox, but you’re also educated enough in language to know what a paradox actually is lol
Nice video, and as you can see people are nitpicking. I think they fail to understand that we try to word it so a person who is not a Physicist will understand it.
if people where specific to begin with rather than coy pasting others interpretation of the subject and creating bad terminology or lingo there would be less misconceptions
I assume educated people can read and make up their own minds or be inspired to do research them self . or try out if things work or not all tough your gonna get a lot of skinned cats and contrarians ..and few not dignified a response.
@@mortenjacobsen5673 I don't disagree with you, but I'm guessing people watch youtube vids like this because they can't or don't have resources to confirm it.
@@wilhelmpaulm the sad truth is that you tube is not the best source for education and the club instructors knowledge is basic and wa level 3 coaches ar few and far between , archers divided by the bows they shoot and argue about style while riding their shoot cycle around in circles and few physics doctorates does archery and make you tube videos about it . and its not like any Olympic training centers are either
David, you have certainly stirred the pot! Discuss the 'archers paradox' and watch the arrows fly. Clearly there is a lot of confusion with regard to the basic concept. I'm still uncertain as whether we are dealing with a paradox in its classical definition. Seems to be more of an observation that can be explained by basic trigonometry and physical forces. Flaxen Saxon
I kind of went over the top on this one, but then, I have heard and seen just so much silliness, dare i say stupidity, on this subject. And I point out I'm not referring to NU's, Greg's, or Destin's videos. I sure as blazes got carried away. Why? Certainly not justified with their contributions to putting reason where it should be. I think you have the right approach and attitude in the tone you put to your comments. All this discussion has given me the moment to consider when I first noticed the paradox. I won't go into the details, but the result was a rather short "okay, the arrow is not aligned with the target. I can't explain it quickly or easily, so let's just get on with getting better with the bow." At the end of the day, that's really all that matters.
there is a paradox in the classical sense ,if you remember the idiom straight as an arrow and imagine a straight stick flying trough the air .....then look at some slow motion fotage and why did they not call it khatra if that has been around since feudal japan and the medieval ages ?
Thank you. I've been wondering, how simple homemade Bows, and other Bows without that cutout design, how they work, without the arrow flipping & hitting the bow. Does this also mean, I can use Crossbow bolts, or homemade arrows made from durable, rigid, metal rods, with a Bow that has that cutout design?
Yes, the arrow will have some deflection, always. The arrow always flexes just from the acceleration force generated, even if your bow and release are "dead-on" center. it just depends how much that it is, and the arrows you are shooting will factor into how much they are deflecting in addition to your bow and your technique.
I thought you were going to talk about the “archers paradox” from logic, about how an arrow that keeps traveling half-way to a target can never actually hit the target. Didn’t know there were two concepts labelled “archers paradox”.
arrow wriggle is simply a law of physics...the back end of the arrow thrusting against the front end of the arrow...something has to give...= the wriggle...
Hi Nu sensi! I recently bought my first bow and it come with a new string. It was not until I asked someone at the club to string it for me, that I realized bows from different manufactors ask for different string length. My bow, 68'' fivics titan with sf a+ limbs needs 68'' and my string was 64.5'', typically used on 68'' w&w bows. Would you please make a video on this topic? Thank you!
Afraid you may be adding to the confusion about archer's paradox by injecting an non-essential observation into your discussion. If I understand you correctly, you're saying that archer's paradox is the unrecognized difference in the angle between the arrow on the string at rest/brace and the angle at full draw. That is, the arrow points to the left (for a right hand shooter) when the arrow is on the bow at brace, and at full draw, that angle is greatly reduced or eliminated and the points toward the target. And thus, that the lower or non-existent angle at full draw explains why the arrow goes straight to the target rather than careening off to the left, which is what one would expect from seeing the arrow on the string at brace. That's not quite right. The paradox is that, in either case, at brace or at full draw, the arrow is pointing left (for a right hand shooter), albeit less at full draw than at brace, yet the arrow hits the target when shot. Common sense/observation would suggest the arrow should careen off in the direction it's pointing, and yet it doesn't. That's the paradox. The amount of the angle that the arrow is pointing off target is reduced at full draw, but it does not go away. Regardless, the arrow does not leave the string until it reaches brace height or beyond so it is back to it's original orientation at release. You can move the bow riser to point the arrow directly at the target, but the arrow's orientation on the bow is still pointing to the left (for a right hand shooter). I.e., the paradox still exists. You are correct that the reason the arrow flies straight off the bow is because it flexes around the riser, if it is spined correctly, and that the flexing of the arrow is the response to paradox, and helps explain it, but it is not the paradox itself as many believe. And, of course, as you point out, there is no paradox with bows cut past center in which the arrow lines up perfectly with the string. The arrow still flexes as it leaves the bow due to the force of the string putting a static object in motion and the idiosyncracies of a finger release. Perhaps I misunderstood the opening few minutes of your discussion. In short, I'm suggesting that the difference in the amount the arrow is pointing away from the bow (at rest or full draw) is not essential to understanding archer's paradox. The essential/defining fact is that it's pointing off the bow and yet it hits the target. That's the paradox, the observation that seems counterintuitive. And the explanation/reason the arrow flies true is that it flexes around the bow's riser.
Can you please explain why arrow spine strength is still an issue when a shooting a center shot bow? I imagine that if the arrow is properly constrained (eg. whisker biscuit arrow rest) at 90 deg to the bowstring, and the bow is shot using a mechanical trigger release (compound bow), spine strength would not influence the flight of the arrow.
@@NUSensei Perhaps I did not make the question clear. I refer to a mechanical trigger type release, which grips and releases the string from both sides, as is commonly used with a compound bow. Releasing from both sides of the string should not cause any lateral displacement. Would spine strength still influence the flight of the arrow?
Sorry, @NUSensei, but I don't think that's the paradox either. It's 'why the arrow flies straight despite pointing off center'. You yourself made a video of how close groupings are amplified in larger ranges and how the distance of 10m fools spectators into thinking the skill is greater than the shots would suggest. Following the same logic, even if you use the smallest deflection at full size and create a vector from that point and follow the arrow, it should still be VERY off target. As such, the paradox isn't that the two different positions, but the lack of deflection of the arrow. For example you state at 11:40 that it MUST correct it's flight to stay on course. That can't be right because there is no course correction on an arrow. It will follow whatever forces enact upon it. It CANNOT correct it's flight. It's just an arrow. So a paradox occurs in that it does correct it's flight despite the fact that it's pointing another way. And yes, the flex/oscilation is the answer to the paradox, and the rest of your explanation is right, but the paradox itself isn't the two different things the arrow is pointing at, but the lack of apparent deflection.
It’s interesting that on a center shot riser for a parallel shaft, several archers have recommended adjusting center shot slightly outside of center. This is supposed to help with arrow clearance. What is your view? Pun intended.
There are differing views on this. Some archers will tune the bow so that it is perfect centre-shot, some insist on the offset even with a plunger. One factor to consider is that a finger-shooter will still induce a lateral force due to the string displacement around the fingers.
I'm sorry but on the traditional bows, even at draw, those arrows are clearly pointing off center target. I agree the paradox isn't the flex itself...but on traditional bows...even at draw, the arrow is not pointing at the target your bow is aiming at. The paradox is that the arrow doesn't go where the arrow is pointing but where the bow is. This is WAY more noticeable on heavier longbows.
@@ehisey you know that trigonometry was applied to build the great pyramids, right? I very much doubt that the "archers paradox" is as a name older than that. Even so archery and therefore the existence of the paradox, is.
@@oldoneeye7516 Hardly Tirg is a later development. The actual thing used was these days call Artisan Geometry. The tools by name were Merchet, Chorobate, and Groma. Trig may describe them, but it was not used to build them, and only known by a few elite individuals. At the time Trig was in its infancy and only really used by Star gazers.
...This is also not the Archer's Paradox I've heard of before in a maths/philosophy context! Whenever I've heard of the Archer's Paradox in the past, it's been an alternate name for Xeno's Paradox...
Actually his explanation completely misses the mark too. His description of what happens is fine, but not what the actual paradox is. It's not the difference between starting position and full draw as he states at 6:09-ish, that's just simple trig. It's the fact that at no point during the draw is the arrow ever pointed straight at the target, and in fact gets further off target as the string comes forward, and yet the arrow eventually travels along the plane formed by the moving string.
I always thought it was, “archers paradise”. We’ve been spending most our lives living on an archers paradise.
lmao
I've always heard it explained as two conflicting facts. The arrow points off line; yet travels in the direction of the string.
That is the nutshell version, and why modern center shot bows dont have the paradox.
Not always, arrow may hits target where it is pointing on full draw too
*In short:*
The flexing of the arrow is *not* the archer's paradox.
The archer's paradox is the perception that the arrow must go through the point of origin in order to hit the target. In other words, the arrow must follow the bow plane (i.e. the string's path) to fly straight to the target. However, when nocked, the arrow points *away* from the target. The arrow must therefore go around the bow in order to enter its intended path.
Because of the offset from the bow plane (i.e. the arrow does not follow straight along where the string should go), a sideways force is induced. The back of the arrow experiences a compression force, and as the arrow shaft is not rigid, this causes the arrow to oscillate. The timing of this is oscillation is what allows the arrow to go around the bow without being deflected.
The archer's paradox is not compensated by the archer aiming off, but by the selection of the right spine (i.e. the flexibility of the shaft) so that for a given bow of a given draw weight, the forces that act on the arrow result in the right amount of flex. Too little, or too much spine, and the arrow will fail to clear the bow, resulting in the arrow being deflected to one side or the other.
There are two causes for the misunderstanding:
1) Most bows today are designed to be shot close to or past centre, hence the "window" in the bow, allowing for more direct alignment, as compared to traditional bows which were not made with this design.
2) The incorrect identification of the flexing arrow in slow-motion videos because it looks epic, though if you pay attention to the narration they usually do explain why this happens.
*It's basic trigonometry*
Except that basic trigonometry doesn't explain why the arrow flies towards the direction of the bow plane rather than along the line of the arrow. The arrow does not travel towards the direction it was pointing at while at brace.
You are so going to have all the experts telling you that you are wrong. Archery 101 has two videos explaining this and they came out in comments with their engineering degrees saying the paradox was the fact the arrow appears to go through the riser, or that the spine was the paradox.
@@incorporeal3793 Thats what I always thought. That even though the arrow is pointing off target at full draw, the arrow flexes around the riser and travels in line with the string and the middle of the riser to hit the bullseye, hence appering to travel through the riser. Therefore even though the arrow is pointing to the left (or right depending), it still flies straight, hence the paradox. Now l don't know what's right or wrong anymore. It feels like my whole life is a lie.
Nu sensei i practice with my bow by my self and when i shot i use it inclinated to the right so i can aim better with the arrows tip is this wrong o affects the accuaracy in some way? Thank you for your time and the paradox video :)
@@incorporeal3793 i asked about these engineres ,no reply and not once was en.wikipedia.org/wiki/Euler%E2%80%93Bernoulli_beam_theory mentioned neither was hooke en.wikipedia.org/wiki/Hooke%27s_law or newton . not a mention that the archers paradox was an invented terminology , a simplification
@@mortenjacobsen5673
Here is a scientific breakdown of it, sorry no Illustrations. This is from 1910 btw.
The Toxopholist's Paradox
By E. J. RENDTORFF
A PARADOX is a statement of fact apparently opposed to common sense. Why is it that an arrow will fly along its aimed course instead of several degrees toward the left, when it is held on the side of the bow with the string pushing it further to the left as the nock approaches the bow ? The fact that it does fly true, instead of shifting radically off its course, as we would naturally expect, constitutes the toxopholist's paradox.
Ford, Butt and Walrond have explained this phenomenon to us, and for several decades their ideas have been accepted and passed unchallenged. It takes some little nerve for a novice to stale publicly his unbelief in the classical explanation. In order to explain my heresy I shall attempt to discuss the various phenomena that enter, give my conclusions, and then let our archery friends act as the jury.
Figure 1 represents an arrow full drawn and ready for release. The center of gravity of the arrow is at G. On release the force F exerted through the agency of the string moves the arrow forward. The arrow starts from rest and accelerates in velocity until it leaves the string, after which it travels with a uniform velocity, except as it is slowed up by the friction of the air.
Now, everybody at rest has a tendency to remain at rest. This tendency is called inertia. The existence and action of inertia can be illustrated as follows:
Attach two strings with a breaking strength of about eleven pounds to the top and bottom of a ten-pound weight. Suspend the weight from one string, with the other one hanging loosely below. A slowly acting force of but one pound exerted on the lower string will suffice to break the upper one; but if the lower string be jerked rapidly the weight will remain hanging while the lower string breaks.
Effect 1. When the arrow is released and the bow string moves forward, the angle D N G constantly increases. This gives the center of gravity an accelerated motion toward the left. The inertia of the arrow thus produces the force C, which tends to prevent the angular displacement.
This force C becomes constantly greater until the arrow leaves the string, because, first, the arrow accelerates in velocity; and second, the angle of displacement constantly increases. The force C produces the two balancing forces B against the bow, and A against the string.
While the center of gravity lies within the bow, the force C will produce a slight bending of the arrow, with the concave side toward the left. It is the force B which prevents the arrow from falling away from the bow, and not a problematical twisting of the string, as some of our English authorities have stated.
In Figure 2 are illustrated the conditions applying when the center of gravity of the arrow has passed the bow. The forces C and B remain in direction as before, but they have increased in magnitude. The force A is zero when G is opposite the bow, and then changes in direction and increases in magnitude until the nock leaves the string. The force C now bends the arrow toward its aimed course, with the concave side of the flexure toward the right. This corresponds exactly with the statements of Walrond, Ford and Butt, with the following exceptions: They do not mention the forces A and C, but assume the existence of B only (which Ford calls a blow) and ascribe to it the various bendings of »the arrow. Now. as the force B always pushes the arrow directly against the bow, no turning moment can exist and the force is therefore not operative in any of the motions of the arrow as described.
Effect 2. They also mention the effect of the feathers throwing the nock to the left, as the feathers pass the bow, thus helping the alignment of the shaft.
Giving our English friends full credit for the two reasons so far deduced, let us proceed with our inquiry. The force A increases as the string approaches the bow. When the nock leaves the string, with the customary clearance of about 7 inches, the force C would be about 10 inches beyond the bow for my 29-inch arrows. The equation for equilibrium would be
A x NE = C x GE
At this moment the angle D N G is increasing at its most rapid rate, while the velocity of the arrow has reached its greatest value. In other words, the force C is now at its maximum value, while the force A is 10/7 times larger than C. What happens?
Effect 3. The force A moves the bow string toward the left, thus relieving the bending of the arrow and decreasing the shifting of the arrow out of its aimed course.
These three effects are operative, but are they sufficient to explain the paradox? If they were sufficient it would follow that a bow held rigidly in a frame, with the arrow released either by hand or by some trigger contrivance, would project the arrow at least as well as when shot by an archer. Let us see what Dr. Elmer has to say about the subject. I shall quote from a recent letter: "What do you think of a mechanical support and trigger for a bow as a method for testing arrows? I made one and it gave results that were very surprising. For instance, the arrows flew rather wild and showed a very marked tendency to buckle. What astonished me still more was that they veered off to the left. This made it seem likely that ordinarily the bow is slightly pushed to the right by the arrow."
Although we have already added one new reason to those formerly accepted as sufficient, we are apparently not yet entirely on the correct track, so let us continue the study of our force diagram.
Effect 4. From the instant the center of gravity of the arrow leaves the inside of the bow until the nock leaves the string, the force A offers a considerable turning moment, tending to turn the plane of the string and bow toward the left. The magnitude of this turning moment is the product of the force A multiplied by the distance N E. The distance N E varies from 17 to 7 inches, but as it decreases, the force A increases, so that the turning moment remains fairly constant and of considerable magnitude.
In Dr. Elmer's machine the bow cannot turn, but in the archer's hand it can and does.If not properly controlled it will move the bowstring against the arm guard.
Effect 5. When the arrow is drawn the left arm is under considerable strain and the hand moves slightly to the right. On release, the removal of the constraining force moves the arm somewhat to the left. The muscles do not respond at once, due first to the inertia of the arm and, second, to the fact that muscular movement does not begin until a certain time after stimulation. As the arrow remains in con tact with the string for about 1/40 of a second, after release, the motion of the arm toward the left is probably negligible until after the center of gravity of the arrow has passed the inside of the bow and then increases in magnitude until the arrow leaves the bow. This would have the tendency of moving the nock toward the left, thus pushing the arrow back parallel to its aimed course.
This last effect cannot be proved through the use of mathematics as it depends upon several variable factors than cannot readily be determined, such as the exact period when the muscular recoil is operative. I derived the conclusions mainly though a prior reasoning. The following facts seem to prove the conclusion correct. When the nock leaves the string the force A no longer acts against the arrow. This would greatly diminish the force B and consequently produce but little wear on the shaft along the last seven inches of the nock end. My old arrows show considerable wear in this zone, which leads one to believe that the fifth effect is operative to a marked extent. In addition to this, arrows when shot buckle far less than they would if effect 1 were the main factor.
The first three effects are operative in a mechanical contrivance, such as that used by Dr. Elmer. The fact that this machine shoots badly to the left and buckles the arrows, as it theoretically must, shows that the last two effects are not only operative but are probably the chief factors in the solution of the problem. The relative magnitude of the various effects depends somewhat upon the personal equation of the archer, when he, through intuition, gets the five effects balanced he is able to shoot without lateral displacement, or undue buckling of the arrows.
I believe we are now prepared to solve the problem, discussed in a previous article, pertaining to the effect of a variable point of balance of our arrows. A variable position of the center of gravity alters the relative magnitudes of Effects I, 3, and 4. As just mentioned, an archer shoots without lateral displacement when all five effects are properly balanced. A difference in the position of the center of gravity of our arrows changes the relative magnitude of three of the effects, so that an exact balance of all five effects cannot be maintained, unless the point of balance of each separate arrow corresponds closely to the remaining arrows of the set.
There are so many video's about the archers paradox here on youtube, 90% of them are wrong and the rest are so confusing that most viewers in the end stil don't know what the actual paradox is.
There are 2 archers. Archer A and archer B
Archer A has a modern hunting bow that is cut to center. If he aims, his arrow, his string, and his bow are in 1 line with the target. When releasing the string his arrow wil hit the target. This is logical.
Archer B has a traditional longbow with no shelf. If he aims, his arrow, his string, and his bow wil NOT be in 1 line with the target, EVEN at full draw. When releasing the string his arrow wil also hit the target. This does not seems logical, and thats the "archers" paradox.
more like a difference frequency of oscillation
And there is archer C, being a thumb archer doing a torque or khatra of the bow in release, so that the arrow does not have to pass the bow....
@@karlgunther-turkisharchery4272 the flight of the arrow is decided at the nano second of release as the front node of the arrow pushes of the riser for khatra to work you need to be insanly faster than human reaction time of 0.3 second at best or faster than the arrow , or the arrow has the right spine so the clearance is good with or without khatra
@@mortenjacobsen5673 Spine for thumb archery is not that important....
@@karlgunther-turkisharchery4272 nothing is unless you want to hit the target with some degree of consistency ,
I have for awhile understood the archers paradox. And your explanation is probably the best I've heard.
Good explanation but one point of clarification needs to be made, imo.
The arrow doesn't correct itself by it's own volition (of course) nor is it caused by the string rolling off the fingers. If that were the case then arrows fired from a bow using a release aid wouldn't flex. Even crossbow bolts flex, albeit very little in relation to arrows. The flex is down to physics, specifically Newton's first law: an object at rest tends to stay at rest until acted upon by some external force. In this case the arrow is the object and the string is the external force but it is important to remember that the force acts upon the nock and the nock then acts upon the shaft which, in turn, acts upon the point. So what happens is that the force travels *through* the arrow while the point is remaining at rest. *This* is what causes the flex.
Yes Sir, you explain it correctly.
Flexing = Mass Inertia of the arrow Point + Internal Force that travel through the Arrow Shaft.
Btw, Internal Force would have similar Newton with the DRAWN STRING force.
You're right, he says in the video that the arrow bends to get around the bow, but it doesn't. It bends because the nock starts moving before the point does.
Thank God someone actually knew this
I hate how much this guy talks about others giving misinformation then says some garbage like this
The flexing is the solution to the paradox
No it's not
@@vodoopupped9687 yes it is. The paradox is "hey, the arrow is pointing to the side not straight at the target, but it still goes straight to the target even if it's pointed to the side. Weird, it's a paradox". The solution is that the flexing allows it to get around the bow and into the target.
@@vodoopupped9687 you just don't understand what you are reading
@@vodoopupped9687 considering you're telling us we are wrong while also saying the same thing we are saying, yeah you don't understand what you are reading.
@@vodoopupped9687 it's astoniajing how little reading comprehension someone can have. Now please, let's stop this conversation before you give me an aneurism.
This is an excellent explanation of archer’s paradox. I own 3 English Warbows, as well as a number of modern traditional recurve and long bows with the cut out shelf for the arrow. This lesson helps me to better understand how the arrow travels to the target.
I really never understood the concept until now. Thank you for another exceptional lesson!
I see your practice warehouse has some ventilation holes, great for hot days!
Good explanation, I like how professional your videos and I can’t see how you can only have 100k subs, you deserve a lot more in my opinion
I was really excited the first half of the clip because I thought I have FINALLY found the one clip on youtube that explains the Archers paradox correctly! Then I was disappointed when you got to the actual paradox which is a shame, because everything else is correct, and in my opinion the best video I have seen that explains how the paradox is *not* really about bending arrows. As you said: a paradox is a contradiction that seems to defy logic. However, the fact that the arrow changes its angle to the target as you draw it back does *not* contradict normal intuition. That is just basic trigonometry. It is nothing surprising that contradicts intuitive logic. So that is not the paradox. The paradox *is* the fact that the arrow will fly in the direction it has at full draw even though logic tells us that the arrow must pass through the position at brace height as it travels forwards, and at this position it points off target, so it shouldn't fly straight towards the target. *This* is the paradoxical part that contradicts intuitive logic. The slowmo shots of the bending arrows show us how the arrow can clear the handle without being deflected, so in other words, why this apparent paradox isn't an actual physical paradox. If you could re edit a minute or so in the middle of the clip I would be so happy. I have commented on this subject on one of the other big archery channels where the channel owner had made a poor attempt at "clearing up the confusion" and he basically just responded aggressively and removed my comments.
"he basically just responded aggressively and removed my comments" - Maybe I removed your because you resorted to name calling? Funny how you left that part out.
"If you could re edit a minute or so in the middle of the clip I would be so happy." - wow, that is an arrogant request.
@@3DArchery The comments are not there anymore so we can't really go back and check can we? But no, I was nothing but civil. The other person who actually started the thread and agreed with me got fed up though...
Magnus Wendt yeah Greg got it wrong then acted like a dick about it, haven’t been there since.
I think your explanation is better, however the arrows trajectory will depend highly on the spine of the arrow. So perhaps, to satisfy everyone's misconceptions the paradox might be more along the lines of: the arrow might not hit any of the geometrically centered points between full draw and brace height, based on its spine.
Thank you for making a post that was exactly what I was going to say before I said it. If you could edit the comment so that nothing after “… actual physical paradox.” was included, it would make me so happy! Then the useful parts of the comment would be there without all the drama. Maybe this thread could disappear too.
Destin from #SmarterEveryDay has a great video on archers paradox.
It's a very good video that explains it clearly. It's also the video that people don't pay attention to, as many viewers get tunnel-vision on the slo-mo flex and then try to backsplain using that snippet.
@@NUSensei
Nu? How common is it for you to share your names?
Just curious if it's a common surname?
@@nair.127
About 40% of the Vietnamese population.
@@NUSensei xD
BEAUTIFULLY explained ... nothing beats a visual explanation. Thanks NUSensei.
When you drew that arrow back pointed at the camera it made me feel very uncomfortable. LOL
Great video as always! I just got my Nika Black Phoenix in this week. I sanded down the handle a little but I love it! Thanks for the review you did on it!
Very helpful video. From one archer to another
NUSensei, very good explanation. Greg from 3D Archery did one also and was very well done. Some will get it some won't want to and you will not be able to change their minds. Thank you.
excellent explanation and easy to understand. Additionally, I am of the position that some of the flexing of the arrow is the result of the stored potential energy in the bow being converted into kinetic energy. The arrow goes from "full stop" to "full speed" and the flex is the result of inertia and the energy transfer.
This is how the paradox works. The back of the arrow is being accelerated by the arrow, while the front of the arrow is inert.Because the string is moving along a different plane, the back of the arrow is forced along that plane instead of where the arrow is pointing. This is what causes the arrow to flex, and the spine of the arrow allows it to clear the bow as it oscillates because of this initial flex.
You have an amazing workshops. Inspiring stuff! You have so much passion for your craft!
Thank you NUSensie for explaining that way better . I had a feeling some people were getting it wrong . Love what you do man . Keep up the good work🍻
Seen a lot of archers paradox videos. Like this one the best. Think it comes closest to my idea of the paradox which is, simply stated, that in order to hit a target in front of you you have to start with the arrow pointed away from the target. The rest of the videos deal mainly with why this works; i.e. arrow spine, how close to center the riser is cut, etc.
the archer's paradox is me hitting a bullseye with zero skill
I became a smart painter watching Bob Ross and a smart Archer watching you're shows thanks.
Here's my take:
The flexing will happen however the arrow is released, the spine of the arrow is not enough to prevent column buckling due to launch forces (except for a crossbow bolt where flexing would be bad). The spine has to be enough to prevent excessive buckling (which can break the arrow and reduce accuracy). Finger release (and nock height) will ensure the initial flex direction is consistent, which I think ensures the fletching should clear the arrow rest - some high speed photography would be good to see on this for modern bow and various settings and release methods.
Hey Nu, can you do a video about arrow spine as you already talked a bit about it in here? How much spine is good for how much poundage, what does it affect? Thank you :)
Thanks for sharing! Always happy to see this topic brought up.
Didn't realise how much you're channel has been growing! Good work!
@@NUSensei I've gotten some help along the way. Notably some from a fellow educator in a different hemisphere. ;)
Nice video, thank you for the explanation!
Have a good day :)
Awesome explanation Nu, love the way you do your vids. 😎👍👍👍
All this for historical bow would be most obvious from above. Then we could see the line running from the tip of the arrow straight to the target centre, while the continuation of the shaft would be another line, which goes at the angle from the first one away from the centre of the target to the left (for the right hand archer).
I'm getting smarter every day by watching videos like this.
The part that is the actual paradox seems like simple geometry:
Consider three points, the bow (X) the string (Y) and the rest of the arrow (Z). At brace, angle XYZ should be a much bigger measure than angle XYZ at full draw. Adding point W, the target, in line with X and Y, you can easily figure that the angle between the target and the rest (with the string as a vertex) will be bigger at brace than full draw. Hopefully this clears it up for someone
I'm so happy that my decades long campaign of educating people about what "archers paradox" actually is, causes so much angst with people who think it's about arrows bending.
Great video. I never considered the paradox from that point before.
“Fire” and “arrow” evokes a physical reaction out of me every time
Finally, I understand this. Many thanks
My understanding is that the Archers Paradox is : How can the archer shoot straight when the bow is in the way of the line between the string and the bow centre?
As you rightly point out, when the arrow is pulled back its angle of deviation from the bow/string plane lessens. So when you fire an arrow it's angle of deviation from the bow/string plane increases as the string pushes it forward.This causes the arrow to press against the bow, and induces the oscillations in the arrow. The first oscillation in the arrow, curves the arrow slightly around the bow, and the arrow continues to oscillate on its way to the target. I hope that makes sense.
Hi NuSensei. Good video and nice explanation about "archer paradox". However, the arrow flexing is not only consequence of finger realesed (as it seems in your explanation). The energy stored in the limbs in full draw, released suddenly, is the main reason for the arrow to flex.
Ok when I heard you saying that this wobbling is the result of the paradox i was like: "what!? wtf!?" and just when I started writing that this paradox is not at all about how the arrow fly but about the arrow hitting the target when logicly it shoudn't ever reach any target at all, I looked for it on google. Turns out this actually is the archer paradox and what I was thinking about is the arrow paradox :D
Every day you learn new things I guess...
Great knowledge 🙏🏽
Its all the transfer of energy from the bow to the arrow. starting with string vibrations and its movement back toward the center of the bow. as well as finger release, causing increase vibration or string movement to the right or left, friction from the rest, as well as how long the rest holds the arrow, (the longer the more level will stay,but increases friction). It seems to me that ''silencing'' cutting down on friction and a longer rest that is adjustable is essential for the shortcomings of the re-curve. Finally if your string, rest and arrow don't line up its going to hit the side of the riser, and if you release and move the bow it affects the direction. ( making it go left at high spine rating as a result of the rest not being at the dead center of the bow, and flex and move left at lower spine ratings). I guess thats why ppl use dampeners, balances, and adjustable rests.
So, for someone like me, who wants to start in archery, as a right handed that wants to use a bow with the cutout on the right side (it just feels better that way for me), the only way for me to shoot the bow properly, is to use a thumb draw. for a three (or two) finger draw, the cutout must be on the left side of the bow. love your videos btw!
Thanks, Nu that was very informative :)
There IS a paradox where you do sort of get loss of power because of the flex, a second archer's paradox if you will. It's utterly irrelevant for target shooting, but it's there. The idea here is that the same arrow fired from the same bow at same draw length has more effect on target at 10 meters than at 5 meters, which is counterintuitive.
The mechanics are pretty easy to understand - because arrow shot from a traditional bow is flexing and tilting, it will not hit directly, i.e. with its entire mass behind the point, pointed in one direction. (Flexing dies waste energy, but that alone doesn't create a paradox, just lessens the total joules available).
Just about the only place you can notice this is when you are shooting at thin, hard material that is close to what the given bow can penetrate. Thing is, that is pretty much the definition of armor, so you can get a strange situation in testing bows against metal armor, where the armor mostly stops arrows at short distances, but is penetrated at longer ones. One additional thing to remember is that armor doesn't have to stop the arrow, just deflect it, and that's far easier to do when the hit comes in at an angle.
This gets more and more pronounced if you use a heavy bow with wodden arrows with straight shafts - the historical ones were barrell-shaped.
This paradox disappears very shortly, and after about 10-20 meters, arrows behave the way you'd expect them to.
So, paradox is that effect on target doesn't look like 6-5-4-3-2-1, but as 3-4-5-4-3-2-1
Thanks, man! Very good explained, I know understand the archer's paradoxon :)
The paradox is shooting around the bow. Meaning how you showed at brace the the arrow flys it should go the direction it points when it comes back to brace flying off to one side because of the bow being directly in the path of the arrow. But instead because of the tolerance of the arrow it bends with the pressure of the release of the string causing it to bend and curve around the bow and go straight
To make it barely simple, where your arrow shaft points at full draw is different from where your arrow shaft points at no draw. This is the part of archer's paradox that everyone agrees. However, where your arrow flys to after leaving your bow depends on the combination of all factors: draw weight, draw length, spine stiffness, arrow head weight, and even your finger's subtle deviation on releasing. Even the spine chart for selecting your arrows may not be always right. For me, I have a 22lbs PSE snake. I have to use 340 and 400 spine carbon arrows to make it fly to where I point my arrow at full draw. If I use 600 spine arrows or even fiberglass arrows that I selected by spine chart and bought, all fly to the left. So key discussion in this video is the difference of your arrow shaft pointing to at full draw and at no draw. Where your arrows fly to when leaving your bow depends on everything combined.
Nice
That's the part that is wrong, that's not a paradox, that's trigonometry. Your arrow ISN'T supposed to fly in the direction it's pointing at full draw, it's supposed to fly in line with the force of the string, which happens to be through the bow. But, as with most things, if it works for you, keep doin' it.
The other thing to remember is that the arrow is a projectile, not a rocket. It doesn't fly where it is pointed. Due to the fletchings, it points where it flies. The string always pushed the arrow in the direction that the bow is pointed, so the arrow flies in that direction but points in another direction momentarily. Since the arrow is not a rocket, there is no force pushing the arrow in the direction that the arrow is pointing. The Law of Conservation of Momentum demands that the arrow fly in the direction that the string pushes. There is no physical law that demands the arrow fly in the direction that it is pointing.
huh! I learned something today. I thought the "paradox" was that at a certain point adding energy (a higher draw weight) would not result in the arrow going faster because it would start to flex more as the string accelerates it and therefore may even travel slower through the air due to the increased aerodynamic drag.
Arrow (whispers to archer): 'After 5000 years of this paradox crap, isn't it time the bow got out of the way?' Bow: 'Noooooooooooooo!!!' And that ladies and gentlemen, is how the mutant centre cut bow was born
I do not have my bow yet as it is (or so I have been informed) now in the post, I have been stressing over this spine issue and struggling to understand why it matters so much with compounds which are all (or all the ones i have checked out) centre shot bows..
I understood the paradox long ago, long before developing a serious interest in archery, and my gut feeling was the only major issue with spine and a compound is that too week a spine could end up breaking under to force of a heavy bow.. After watching your vid It would appear that my gut was right, to a point at least..
I must say also that I find your instruction style and video presence superbly informative and engaging, many thanks for sharing your passion and knowledge ;)
Now we just need a bow with a magnetic levitating window which suspends the arrow magnetically, and upon release, sensors monitor the flex and trajectory to actively correct the arrow as it leaves the bow.
Great Explanation Mate
Talking about the fletching limiting the movements, I shoot compound. When we are setting up our arrow drops and tuning our bows, we test shoot arrows without fletching to insure our arrows are being released with neutral forces.
then why put thatching on and what are you actually testing ?how it flies without thatching , but your gona use fleatchings.... i call it lunacy others bare shaft tuning. feel free to explain
@@mortenjacobsen5673 You're checking your centers on your drop away or arrow rest and if you have a bow with two cams, if they are in sync with one another. A fletched arrow will tell you you're off but it might not tell you which way. As it'll correct its self go through your paper target looking as if it was off the other direction. A non fletched arrow will exaggerate what's happening. This becomes more important if you plan on using broadheads that counter to self centering effects of fletchings. (Not all states allow mechanical broadheads that stay shut in flight)
@@michaelt6413 then you canjust tune the fleatched arrow the tear will tell you but just the exit flight ,cam sync I do by fell and visual since the d loop can cause tears too and effectnock travel . i could never get the drop away to fall fast enough so went fo ra blade
Excellent explanation
Thank you
Paradox is the same as parallax error while using a range finder or twin lens reflex camera doing close-up photography.
That is absolutely NOT the archer paradox, that's math, the archers paradox is however, that the arrow (with the correct spine) will travel in the direction of the string instead of the direction it's pointing, even though that path is being blocked by the bow. SmarterEveryDay has an amazing video on it, and the first 3 minutes explain it really well. What was said in this video at around 7:50 is the archers paradox.
I love the holes in the tin walls. Whoops.. lol
All good, it happens to all of us.
Builds character in the building.
😊
It's the club shed. A couple of them are drill holes, but a few were from accidents in the shed.
you have to curve the arrow to shoot straight, that's the paradox I was told. stiff arrows don't flex and will bounce off the riser.
So how do you aim an arrow on a self bow?
A) when the arrowhead is over the target line
B) line of sight along the arrow
C) other
It looks like because of your elbow hinge as you draw, the hand travels back at an angle, but then straightens up (in relation to the target) as you find your anchor...
The fact that the arrow flies to where the center of the bow points rather than where the end of the arrow points - sounds paradoxal to me. While the fact that arrow angle changes when you draw - does not.
Well I've learned something today.
The flex is also the result of sudden acceleration of the arrow isn't it? That's why center-shot compound shooters still have to factor in arrow spine.
Great video.
Khatra is not necessarily for clearance AFAIK.. It can be depending on tradition, but from my experience it's mostly a sort of follow-through, but for your bowhand. Perhaps not quite the same, but olympic archers sometimes let their bows swing forward after a shot, kinda like that. Great video as always, keep it up!!
khatra vs Newton epic rap battle of archery !!!! begin.......
Sorry, what olympic archers do is not a khatra, they just drop their bow....
@@karlgunther-turkisharchery4272 depends on the archer and the style but the bow should drop cause of the lose grip and ex ess force forward as a result of less torque and good alignment and some doit as a useless flurry . unless you know all archers you are making assumptions and arguments from ignorance . and bytw i dont drop my bow caus i dont use the bow hand release technique ..some could say its a version of khatra but then you need a clear definitiv of khatra
@@mortenjacobsen5673
ua-cam.com/video/8whS-iFAJsI/v-deo.html
Says all, what I think about it. But I don't no anything about modern olympic archery, I only was tought how, why and when to perform khatra....
@@karlgunther-turkisharchery4272 I agree. It's just that it seems similar to me. I didn't mean that they Khatra, they do not.
Paradox is when focus on shoot, target, technic .. and miss :D
Lmao the real archer's paradox
Nu. That's fun.
The comment fight has begun.
The word knives are out.
The punctuation arrows wiggling through the air.
And I can't resist adding bad humour.
Butt in my defence. I shoot for fun not physical fitness.
Oh wait that's physics, oops.
Cheers mate
Bad humour you want? Well, your butt is on the line, but all is not lost. The message is clear anyway.
Best, D
In fact, the phenomenon the Archer's Paradox names isn't even a paradox. It was just something people wondered about and now we know why it happens.
What is the "archer's paradox"?
The term "archer's paradox" was coined because it was at the time not understood how an arrow could be aimed directly at the mark at full draw, yet be offline at brace height and upon returning to departure, but still recover and go where it had been pointed at full draw. This was the paradox.
Many, if not most of the illustrations which accompany this definition all too often have a tendency to add to the confusion by not usefully representing what really happens.
The most commonly quoted and misleading definition of paradox is that "the arrow bends around the bow and recovers to go where the bow is pointing".
This definition is not useful since it is more obviously natural and efficient to point the arrow at full draw directly at the target.
This done, it is of no interest to the archer where the bow might be pointing, since it is not about to go anywhere.
But this presumes that we match our shafts with this in mind: that it should go where it has been pointed at full draw.
never heard of this, knew the arrows bend but I never knew someone would call that in a weird way.
they don't call the bending of the arrow the archer's paradox, as he explained. people who do this are mistaken.
Thanks, man.
I laughed at you recalling the misuse of the use of A.P. compensate for it mwhahahahahahahahaha
When you’ve been shooting long enough to know what people mean when you hear them using paradox, but you’re also educated enough in language to know what a paradox actually is lol
Thank you for a great knowledge video ! I finding the answer about these question for a while :))
very good video
Nice video, and as you can see people are nitpicking. I think they fail to understand that we try to word it so a person who is not a Physicist will understand it.
if people where specific to begin with rather than coy pasting others
interpretation of the subject and creating bad terminology or lingo there would be less misconceptions
@@mortenjacobsen5673
Or they could be book know it all's who can't shoot worth a damn but love to correct others.
I assume educated people can read and make up their own minds or be inspired to do research them self . or try out if things work or not all tough your gonna get a lot of skinned cats and contrarians ..and few not dignified a response.
@@mortenjacobsen5673 I don't disagree with you, but I'm guessing people watch youtube vids like this because they can't or don't have resources to confirm it.
@@wilhelmpaulm the sad truth is that you tube is not the best source for education
and the club instructors knowledge is basic and wa level 3 coaches ar few and far between , archers divided by the bows they shoot and argue about style while riding their shoot cycle around in circles and few physics doctorates does archery and make you tube videos about it . and its not like any Olympic training centers are either
David, you have certainly stirred the pot! Discuss the 'archers paradox' and watch the arrows fly. Clearly there is a lot of confusion with regard to the basic concept. I'm still uncertain as whether we are dealing with a paradox in its classical definition. Seems to be more of an observation that can be explained by basic trigonometry and physical forces.
Flaxen Saxon
I kind of went over the top on this one, but then, I have heard and seen just so much silliness, dare i say stupidity, on this subject. And I point out I'm not referring to NU's, Greg's, or Destin's videos. I sure as blazes got carried away. Why? Certainly not justified with their contributions to putting reason where it should be.
I think you have the right approach and attitude in the tone you put to your comments.
All this discussion has given me the moment to consider when I first noticed the paradox. I won't go into the details, but the result was a rather short "okay, the arrow is not aligned with the target. I can't explain it quickly or easily, so let's just get on with getting better with the bow." At the end of the day, that's really all that matters.
there is a paradox in the classical sense ,if you remember the idiom straight as an arrow and imagine a straight stick flying trough the air .....then look at some slow motion fotage and why did they not call it khatra if that has been around since feudal japan and the medieval ages ?
Arigato sensei ✨
He's Vietnamese by ethnicity, Australian by nationality, not Japanese... "Nu" is a Vietnamese surname. Sure, the word "sensei" is Japanese, but...
Thank you. I've been wondering, how simple homemade Bows, and other Bows without that cutout design, how they work, without the arrow flipping & hitting the bow. Does this also mean, I can use Crossbow bolts, or homemade arrows made from durable, rigid, metal rods, with a Bow that has that cutout design?
2:50 i cant get the arrow through the middle of the bow handle. *Laughs with PSE Deputy*
Does an arrow shot by a center shot compound bow with release aid still flexes?
Yes, the arrow will have some deflection, always. The arrow always flexes just from the acceleration force generated, even if your bow and release are "dead-on" center. it just depends how much that it is, and the arrows you are shooting will factor into how much they are deflecting in addition to your bow and your technique.
Note that arrow flexes vertically due to arrow "sitting" on rest.
@NUSensei are you going to review war thunder itailan tanks?
NUSense, can you do a video on arrow FOC?
I thought you were going to talk about the “archers paradox” from logic, about how an arrow that keeps traveling half-way to a target can never actually hit the target. Didn’t know there were two concepts labelled “archers paradox”.
That's Zenos' paradox.
arrow wriggle is simply a law of physics...the back end of the arrow thrusting against the front end of the arrow...something has to give...= the wriggle...
Exactly !! what paradox ?? b.s. archer's paradox is shit.
Hi Nu sensi! I recently bought my first bow and it come with a new string. It was not until I asked someone at the club to string it for me, that I realized bows from different manufactors ask for different string length. My bow, 68'' fivics titan with sf a+ limbs needs 68'' and my string was 64.5'', typically used on 68'' w&w bows. Would you please make a video on this topic? Thank you!
I'm sorry for leaving a comment unrealted to this video, however they closed personal message function for youtube.
well done
Afraid you may be adding to the confusion about archer's paradox by injecting an non-essential observation into your discussion. If I understand you correctly, you're saying that archer's paradox is the unrecognized difference in the angle between the arrow on the string at rest/brace and the angle at full draw. That is, the arrow points to the left (for a right hand shooter) when the arrow is on the bow at brace, and at full draw, that angle is greatly reduced or eliminated and the points toward the target. And thus, that the lower or non-existent angle at full draw explains why the arrow goes straight to the target rather than careening off to the left, which is what one would expect from seeing the arrow on the string at brace. That's not quite right.
The paradox is that, in either case, at brace or at full draw, the arrow is pointing left (for a right hand shooter), albeit less at full draw than at brace, yet the arrow hits the target when shot. Common sense/observation would suggest the arrow should careen off in the direction it's pointing, and yet it doesn't. That's the paradox.
The amount of the angle that the arrow is pointing off target is reduced at full draw, but it does not go away. Regardless, the arrow does not leave the string until it reaches brace height or beyond so it is back to it's original orientation at release. You can move the bow riser to point the arrow directly at the target, but the arrow's orientation on the bow is still pointing to the left (for a right hand shooter). I.e., the paradox still exists.
You are correct that the reason the arrow flies straight off the bow is because it flexes around the riser, if it is spined correctly, and that the flexing of the arrow is the response to paradox, and helps explain it, but it is not the paradox itself as many believe.
And, of course, as you point out, there is no paradox with bows cut past center in which the arrow lines up perfectly with the string. The arrow still flexes as it leaves the bow due to the force of the string putting a static object in motion and the idiosyncracies of a finger release.
Perhaps I misunderstood the opening few minutes of your discussion. In short, I'm suggesting that the difference in the amount the arrow is pointing away from the bow (at rest or full draw) is not essential to understanding archer's paradox. The essential/defining fact is that it's pointing off the bow and yet it hits the target. That's the paradox, the observation that seems counterintuitive. And the explanation/reason the arrow flies true is that it flexes around the bow's riser.
So basically you can ignore this with any modern bow thats cut past center?
Can you please explain why arrow spine strength is still an issue when a shooting a center shot bow? I imagine that if the arrow is properly constrained (eg. whisker biscuit arrow rest) at 90 deg to the bowstring, and the bow is shot using a mechanical trigger release (compound bow), spine strength would not influence the flight of the arrow.
The string displacement caused by the finger release still causes a side-to-side deflection.
@@NUSensei Perhaps I did not make the question clear. I refer to a mechanical trigger type release, which grips and releases the string from both sides, as is commonly used with a compound bow. Releasing from both sides of the string should not cause any lateral displacement. Would spine strength still influence the flight of the arrow?
But... Does the arrow go with the path of the draw or the undraw? And should we aim with that gap VS what its at drawn?
Great explanation. Cheers 👍🏼😊
Sorry, @NUSensei, but I don't think that's the paradox either. It's 'why the arrow flies straight despite pointing off center'. You yourself made a video of how close groupings are amplified in larger ranges and how the distance of 10m fools spectators into thinking the skill is greater than the shots would suggest. Following the same logic, even if you use the smallest deflection at full size and create a vector from that point and follow the arrow, it should still be VERY off target. As such, the paradox isn't that the two different positions, but the lack of deflection of the arrow. For example you state at 11:40 that it MUST correct it's flight to stay on course. That can't be right because there is no course correction on an arrow. It will follow whatever forces enact upon it. It CANNOT correct it's flight. It's just an arrow. So a paradox occurs in that it does correct it's flight despite the fact that it's pointing another way.
And yes, the flex/oscilation is the answer to the paradox, and the rest of your explanation is right, but the paradox itself isn't the two different things the arrow is pointing at, but the lack of apparent deflection.
It’s interesting that on a center shot riser for a parallel shaft, several archers have recommended adjusting center shot slightly outside of center. This is supposed to help with arrow clearance. What is your view? Pun intended.
There are differing views on this. Some archers will tune the bow so that it is perfect centre-shot, some insist on the offset even with a plunger. One factor to consider is that a finger-shooter will still induce a lateral force due to the string displacement around the fingers.
I guess do whatever produces the best groups.
so,, do shoot--through risers on compounds still defeat the archers paradox?
I'm sorry but on the traditional bows, even at draw, those arrows are clearly pointing off center target. I agree the paradox isn't the flex itself...but on traditional bows...even at draw, the arrow is not pointing at the target your bow is aiming at. The paradox is that the arrow doesn't go where the arrow is pointing but where the bow is. This is WAY more noticeable on heavier longbows.
So... archers don't pay attention in trigonometry?
The name pre-dates applied trignometry. You need also Newton and Hooke as keeps being pointed out elsewere to get it all to work.
@@ehisey you know that trigonometry was applied to build the great pyramids, right?
I very much doubt that the "archers paradox" is as a name older than that. Even so archery and therefore the existence of the paradox, is.
@@oldoneeye7516 Hardly Tirg is a later development. The actual thing used was these days call Artisan Geometry. The tools by name were Merchet, Chorobate, and Groma. Trig may describe them, but it was not used to build them, and only known by a few elite individuals.
At the time Trig was in its infancy and only really used by Star gazers.
...This is also not the Archer's Paradox I've heard of before in a maths/philosophy context!
Whenever I've heard of the Archer's Paradox in the past, it's been an alternate name for Xeno's Paradox...
That's usually called the Arrow Paradox, not the Archer's Paradox
Your bow makes those movie/video game sounds, or did you add those in the post?
You mean the sound of the bow string and the bow arms flexing? It does that for certain bows.
Actually his explanation completely misses the mark too. His description of what happens is fine, but not what the actual paradox is. It's not the difference between starting position and full draw as he states at 6:09-ish, that's just simple trig. It's the fact that at no point during the draw is the arrow ever pointed straight at the target, and in fact gets further off target as the string comes forward, and yet the arrow eventually travels along the plane formed by the moving string.