Hammer throw "puzzler".!!!

Heres a link that shows a Russian lady Hammer thrower which includes the slow moton video of when the hammer hits the ground... ther are about 4 other people befor the video gets to the blond Russian lady.!!!

http://www.youtube.com/watch?v=Jpbgg2TRCuw

in the video of the Russian lady... when she released the hammer... an observer up in the stands woud have seen the hammer rotatin CCW... but the slow moton part of the video shows that the hammer was rotatin CW jus befor it hit the ground... so when observed from up in the stands... what causes the CCW release of the hammer to a CW rotaton befor it hits the ground.???

I thank i have the only plausable answr... but i woud like to hear other opinions befor i say what it is so i wont influence other peoples ideas.!!!

 

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Is it rotating CW before it hits the ground?

I can't tell.

 

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first time i ever seen that. looks to me like the heavier part is leadign the chain. i dont think any specific 'law' would apply, looks too erratic. could be wrong.

 

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Video is too non-high def for me to see which way hammer seems to be turning when landing.

I have no valid evidence upon which to judge this case.

In absence of compelling evidence otherwise, i will continue to uphold strong belief in conservation of angular momentum.

 

Foreground and background are difficult to resolve on a blurry TV picture. Different people will "see" different things. But if you want to do science, you can get the landmarks of the stadium, the position of the camera(s), track the trajectory in three dimension and work with the original footage to make your judgement.

But I saw no evidence here for new physics.

 

Im qurious if we are talkin about the sam Hammer Throw.???

I cant see the video on my msntv2 internet device so i have to go to the Liberry an use a compuer to see it... but from what i recall from seein it a couple of weeks ago... the Hammer Throw im talkin about (by the blond Russian lady) is about the 5th 1 shown on the video of the link i gave... an after she throws the hammer ther is a slow moton video that clearly shows the hammer rotatin CW (from the perspective of the camera up in the stands) jus befor it hits the ground... an also... the camera showin the release of the hammer shows it to be rotatin CCW... which is also what the camera (observer) from the stands woud have seen (a CCW release)... but reguardlesss of my opinion of the directon of rotaton of the hammer... are we talkin about the sam Hammer Thrower... the blond Russian lady... an if so... after her hammer throw... did you keep watchin an see the slow moton part of the video... when i watached it... it clearly shows the hammer rotatin jus befor it hits the ground.???


http://www.youtube.com/watch?v=Jpbgg2TRCuw

 

The way i see it... the complete hammer (includin the chane) is rotatin on its axis... an that axis bein somwhare inside the heavy steel ball.!!!

 

Did you ever notice that in shoot-em-up cowboy movies the wheels on the wagons turn backward. This is probably the same thing. The strobe effect of the camera shutter and the rotation produces an illusion.

 

This is known as known as the silhouette illusion. The basic illusion is a black silhouette of a spinning girl as seen form the side. Since there are no visual clues to tell you which way she is rotating, you mind just assigns a direction of rotation. And once your mind does this, it is hard to force it to see the rotation as being in the opposite direction.

The rotating hammer fits this because the resolution of the image is to low to make out fine features that would give us the proper visual clues. So all we have is the handle to judge rotation by. Now, if the orientation of the rotation was such that the handle was hidden by the ball at a given point, then this would give us the proper visual clue we need.(if the handle passes behind the ball while going left to right, we would see CW rotation, and CCW rotation if while passing right to left. However the handle passes above and below the ball, so we lose this clue.

Add in the fact that you are watching a flat image taken from a long distance away and you also lose any depth perception clues.

The upshot is that the direction that the hammer appears to be rotating as it hits the ground is a matter of mental perception rather than a true indication of which way it is rotating.

With some effort, I could get the hammer to appear to rotate in either direction to my eye.

So what you have discovered is one the vagaries of human perception.

 

After her hammer throw... several seconds later they show the landin in slow moton... did you see the slow moton part of the video... which to me... clearly shows the hammer rotatin jus befor it hit the ground.???

I agree that the angular momentum was conserved an thats why the hammer rotates on its axis after its thrown... an it continues to rotate on its axis until it hits the ground.!!!

But the real-time video i saw of the hammers release an the slow moton video of its landin was plenty clear enuff for me to determine the hammers directon of rotaton (from the perspective of the camara)... so thats why i queston if we are talkin about the sam video.???

 

Thats interestin... but the landin im talkin about was shown in slow moton so i dont thank that wagon-wheel illusion woud apply in this case... an also... for the wagon-wheel/fan-blade illusion to occur they have to be rotatin perty fast an the hammer rotates "reletively" slow.!!!

 

Once agan... the video i saw of the release an the slow moton video of the hammers landin was plenty clear enuff to determin the directon of rotaton (from the perspective of the cameras)... so thats why i queston if we are talkin about the sam video.???

The queston i have dont require all that informaton... from the perspective of a person up in the stands... they see the hammer bein released in a CCW rotaton... but the slow moton video from the camera up in the stands shows the hammer rotatin CW jus befor it hits the ground... so what acounts for this aparent descrepancy in directon of rotaton.???

Did you see the slow moton video of the hammer landin.???

 

CW is the only directon of rotaton i can see in the slow moton video.!!!

Ive seen that rotatin lady illusion befor an i agree she can apear to rotate in ether directon... but i dont thank thats whats goin on wit the hammer throw video im talkin about.!!!

Can we agree that from up in the stands an observer woud see that the hammer is rotatin in a CCW directon when released.???

Did you see the slow moton video of the hammer landin.???

 

Yes. In fact, it is with the slow motion part that it was easier to make the apparent direction of the rotation change for my part.

I'll stick to my original interpretation of optical illusion.

 

oK... so aparently you did see the sam slow moton video im talkin about... an aparently you can see somptin i cant see or jus ant seen yet (i will look agan nest time i use the Liberry computer)... which is... in the slow moton video of the hammer... jus befor it hits the ground it can apear to rotate CW or CCW dew tp optical illusion... but can we agree that from up in the stands an observer woud see that the Russian lady is rotatin CCW when she releases the hammer.???

 

Below is a snip from a Billy T post to Ken Dine.!!!
=======================

http://www.sciforums.com/showpost.php?p=2013006&postcount=126


"Originally Posted by Ken Dine

Since you're such an observant chap, did you notice that the Russian gal was RAPIDLY spinning her hammer in the counter-clockwise direction prior to release, but that very slow rotation of the ball you noticed was instead in the opposite CLOCKWISE direction????? ”


[Billy T]
No, not originally, did I notice that, but on second viewing I agree that is what the camera records.

However two different cameras were used. One close to the Russian lady and viewing her swing the hammer around from BELOW THE PLANE IT WAS SWINGING IN. The second camera was high in the stands with a telephoto lens and looking DOWN ON THE PLANE the ball and its chain were spinning in. That one camera recorded clockwise and the other counter clockwise is EXACTLY what they should if the spin was always in the same direction.


“ Originally Posted by Ken Dine
....can you explain why the ball shifted from a counter-clockwise rotation to a clockwise rotation prior to landing? ”


[Billy T]
I just did.

[end of snip]


(Pasture Timmy)
The 1 who originaly brout up the Hammer Throw issue was Ken Dine... an he said... jus like the moon... the "Hammer" does not rotate on an internal axis... Billy T says the camera behind the Hammer Thrower shows the hammer rotatin CCW on its release... but dew to the perspective of the second camera which was high up in the stands... the Hammer woud be seen to rotate CW as the slow moton video shows... but thats not true... cause Billy T agrees that the camera behind her shows the rotaton of the hammer to be CCW on its release... an jus because the second camera was high up in the stands... that woud not cause the directon of rotaton to aparently change... nope... not even if the camera was directly overhead.... an others in this thred say the aparent change in directon of rotaton is dew to "illusion".!!!

My take on it is... of course... jus like the moon... the hammer rotates on its internal axis... an i dont thank thers any illusion involved... i thank the camers show esactly whats goin on... an not only does the hammer rotate on its axis CCW 10 to 12 times befor it hits the ground... i suspsect it also spirals 180 degrees by the time it approaches its landin... an this 180 degree "turn-over" is why the hammer apears to have changed its directon of rotaton jus befor it lands.!!!

 

This mite help to put you'r mind at ease a bit (i know it does mine... lol)... cause after a bit of discusson at a diferent physiscs groop... ive gone from bein 99% sure you was rong... to leanin heavily in favor of you'r answr bein absolutely corect... an i cant see the U-Tube video on the internet divice im usin... but im anxious to try an see a CCW rotaton of the hammer in the slow moton part of the (poor quality) video the nest time i have access to a computer.!!!
=======================

[An Edit below]
I looked at the slow-moton part of the video on a computer today tryin to see the hammer rotatin CCW... an on about the 4th try thar it was... a perfect CCW rotaton... so now the mystery is solved in my mind... the hammer is rotatin CCW as it lands (jus as it woud be espected to)... an that it can apear to be rotatiin CW is an illusion jus like Janus said.!!!

Below is a rotatin-lady illusion like Janus was referrin to:::

http://www.news.com.au/common/imagedata/0,,5693171,00.gif

 

Here is a slightly edited copy of my reply to cluelusshusbund´s PM (I don´t like to spend time for only one person):

Why not? Is not the initial camera view from BELOW the plane of rotation and the terminal camera view from ABOVE the plane of rotation? That ALWAYS reverses well defined rotation sense.

The silhouette illusion is strictly 2D image on a featureless 2D background with no masking of anythng. Both camera’s views have huge amount of both foreground and background 3D object collapsed onto a 2D film image. The moving ball is constantly masking something with well known relative distance from you. Thus, it is easy and fully automated with no conscious thought, to tell the rotation direction (and everyone will see it the same sense of rotation).

There are many clues you process without conscious thought to make this judgment, but I will describe only one, which in the literature is called "texture gradient." Typically illustrated by a 2D photo of a 3D field of sun flowers, etc. You have absolutely now difficulty in telling the near flowers from the more distant ones. (You cannot see it any other way despite all flower images in the 2D photo being equally distant from your eyes.)

Likewise the second camera’s 2D image leaves you in no doubt as to which side of the field is closer to you, and which is the far side. Thus, as the ball swings around, it first obscures part of the near field and then later part of the far field. Thus, without the slightest conscious effort, you know with certainty when the ball is moving away from you and when it is approaching you. This has nothing to do with inability to perceive a small percentage variation in depth. (And nothing to do with the silhouette illusion where all these unconsciously clues, like background sequential masking, have been carefully removed from the 2D image.)

 

Yes, by making the motion become unnatural, you can better destroy, or at least consciously over ride, the automatic mental processes that use things like I described in just made post, which normally tell you, with no conscious effort, the sense of rotation.

 

I understan an agree wit the clock esample you gave... how the viewin perspective will make the directon of the hands apear to change directon of rotaton... however i dont thank that esactly applies to the hammer rotaton issue.!!!.

I recall the initial camera view as bein "slightly" below the plane of rotaton of the hammer... but it wasnt far enuff below the plane to record the hammers rotaton as bein CW... the Russian lady was shown to be rotatin CCW as was the hammer.!!!

She was clearly rotatin CCW... therfor when the hammer was released it was also rotatin CCW.!!!

An observer _anywhare_ up in the stands woud have seen her rotatin CCW an woud have seen the hammer rotatin CCW when it was released... an the observer woud have also seen the hammer rotate CCW all the way down the field until it hit the ground.!!!

What got me thankin about that (whether everone will see the sam directon of rotaton) is because of what a guy in another groop said... he indicated that he didnt see what the prollem is... cause in the slow moton part of the video... he sees the hammer rotatin CCW (jus as you woud espect sinse it was rotatin CCW when released)... an the nest day when i had access to a computer... time after time i was able to see the hammer rotate CW or CCW... jus as clearly as i can see the silhouette illusion rotate in ether directon .!!!

Coud you see the hammer rotatin CW or CCW in the slow moton part of the video (jus befor the hammer hit the ground).???