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Re: Viewing the spokes

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benj <nobody@gmail.com> wrote:
> On 09/14/2016 10:47 PM, nuny@bid.nes wrote:
>> On Tuesday, September 13, 2016 at 6:53:01 PM UTC-7, benj wrote:
>>> On 9/13/2016 8:14 PM, nuny@bid.nes wrote:
>>>> On Monday, September 12, 2016 at 6:29:36 PM UTC-7, benj wrote:
>>>>> On 9/9/2016 10:43 PM, nuny@bid.nes wrote:
>>>>>> On Friday, September 9, 2016 at 2:51:31 PM UTC-7, benj wrote:
>>>>>>> On 9/9/2016 12:08 PM, nuny@bid.nes wrote:
>>>>>>>> On Monday, August 29, 2016 at 10:08:25 AM UTC-7, Sergio
>>>>>>>> wrote:
>>>>>>>>> Viewing the spokes
>>>>>>>>>
>>>>>>>>> A wheel with spokes rolls on the ground. A stationary
>>>>>>>>> camera takes a picture of the wheel. Due to the nonzero
>>>>>>>>> exposure time of the camera, the spokes will generally
>>>>>>>>> appear blurred. At what location(s) in the picture does
>>>>>>>>> (do) the spoke(s) not appear blurred?
>>>>>>>>
>>>>>>>>> answer,
>>>>>>>>>
>>>>>>>>> The contact point on the ground does not look blurred,
>>>>>>>>> because it is instantaneously at rest.
>>>>>>>>
>>>>>>>> There is no "instantaneous". The wheel *moves* while the
>>>>>>>> shutter is open, hence the contact patch will move, hence the
>>>>>>>> lowermost spokes will be blurred.
>>>>>>>>
>>>>>>>> Now, if you want to talk about which spokes will be *least*
>>>>>>>> blurred...
>>>>>>>>
>>>>>>> Actually, Mark, only the point of the wheel touching the ground
>>>>>>> which would be the rim is at rest.
>>>>>>
>>>>>> Actually, no, because the shutter can't open *and close*
>>>>>> "instantaneously".
>>>>>>
>>>>>> The contact patch *moves* while the shutter is open.
>>>>>>
>>>>> No it does not.
>>>>
>>>> Yes, it does.  "Contact patch" is that part of the wheel that's in
>>>> contact with the ground. When the wheel isn't moving, neither is the
>>>> contact patch. When the wheel *is* moving, so is the contact patch.
>>>> It has to or the wheel isn't rolling. That's what "moves" means when
>>>> applied to rolling wheels.
>>>>
>>>>> The points on the ground actually rise from the ground
>>>>
>>>> And while they're actually rising, they're actually blurring because
>>>> while they're actually moving the shutter is actually open.
>>>>
>>>>> before moving on so all the contact points are stationary.
>>>>
>>>> There *is no stationary* while the wheel is moving. Each subsequent
>>>> point on the rim that comes in contact with the ground *while the
>>>> wheel is moving* must *also* be moving.
>>>
>>> Ahem. So lesse if I got your "logic" here. The ground is stationary. We
>>> agree with that, right?
>>
>>    WRT the camera, yes.
> 
> Good.
> 
>>> And the rim of the wheel has points that contact the ground.
>>
>>    The "point" isn't dimensionless; that's why the "contact patch" has that name.
> 
> we are talking theoretical "science" now where math is more real than 
> reality so we assume that the rim only touches at one "point". Odd 
> believes that points exist so why don't you?
> 
>>> But no points on the wheel are stationary?
>>
>>    The wheel is *moving* WRT the camera. By definition no part of it can be stationary.
> 
> Absolutely wrong. The bottom point of the wheel is moving BACKWARDS at 
> the average velocity of the wheel forward. The point at the top of the 
> wheel is moving forward at twice the average (or let us say point of the 
> center of rotation of the wheel. Hence the average forward velocity and 
> the backward velocity of the bottom point cancel to give a stationary 
> point on the wheel. We agree?

The point at the bottom of the wheel is continuously changing with
respect to the wheel and moving at the linear velocity of the wheel.

>>> So you are arguing that the wheel is sliding?
>>
>>    No, it was stipulated to be rolling.
> 
> Good.
> 
>>    You keep taking "in contact with the ground" to be equal to "stationary".
>>
>>    This is false.
> 
> How can it be false if the point in contact with the ground is not 
> sliding it must be moving with the ground. In which case it must be 
> stationary.

It is continuously a new point on the wheel as the wheel moves.

> 
>>>>> And that means they are in focus while the shutter is open.
>>>>
>>>> Briefly, then they're not. While the shutter is still open. That's
>>>> why they blur.
>>>>
>>>>> So what you have is a LINE of stationary in focus contact points.
>>>>> No?
>>>>
>>>> No.
>>>
>>> So the rim of the wheel is NOT in contact with the ground. Right?
>>
>>    Of course it is.
>>
>>> Or is sliding.
>>
>>    You aren't really that stupid, are you?
> 
> So when you don't understand the details of the problem your "proof" 
> that you are "right" is to use Chimp's technique of saying everyone else 
> is stupid? Right? Try saying they are "kooks" that works pretty well 
> too! Really makes you look smart! (Just ask HVAC

Take a round object such as a dinner plate and stand it on edge.

Mark the point on the surface and the plate where the plate makes
contact with the plate.

Roll the plate a tiny bit and mark again.

You will have two marks on the rim of the plate and two marks on the surface.


-- 
Jim Pennino

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Thread

Viewing the spokes Sergio <invalid@invalid.com> - 2016-08-29 12:08 -0500
  Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-08-29 18:00 +0000
    Re: Viewing the spokes benj <benj@nobody.net> - 2016-08-29 21:00 -0400
      Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-08-30 01:14 +0000
        Re: Viewing the spokes benj <benj@nobody.net> - 2016-08-29 22:45 -0400
          Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-08-30 04:14 +0000
            Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-29 21:59 -0700
              Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-08-30 05:16 +0000
                Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-29 23:00 -0700
    Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-08-29 18:29 -0700
  Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-29 18:29 -0700
  Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-29 18:46 -0700
    Re: Viewing the spokes benj <benj@nobody.net> - 2016-08-30 19:40 -0400
      Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-30 22:07 -0700
        Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-30 23:48 -0700
          Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-31 09:54 -0700
            Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-09-02 10:00 -0700
              Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-02 13:23 -0700
              Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 11:30 -0700
                Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 13:18 -0700
                Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 14:57 -0700
                Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 16:01 -0700
                Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-04 12:46 -0700
                Re: Red, Blue and Green Ergios <invalid@invalid.com> - 2016-09-07 12:32 -0500
                Re: Red, Blue and Green noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-08 12:12 -0700
                Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-07 23:22 -0700
                Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 16:03 -0700
                Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 16:06 -0700
                Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-20 00:18 -0700
                Re: Red, Blue and Green noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-20 12:52 -0700
                Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-07 10:01 -0700
                Re: Red, Blue and Green Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-07 10:12 -0700
                Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-20 09:47 -0700
        Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-08-31 14:32 -0700
  Re: Viewing the spokes "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-09-04 11:39 -0700
    Re: Viewing the spokes "hanson" <hanson@quick.net> - 2016-09-04 20:36 -0700
  Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-09 09:08 -0700
    Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-09 12:32 -0700
    Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-09 17:51 -0400
      Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-10 00:10 +0000
        Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-09 20:43 -0400
          Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-10 00:57 +0000
            Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-09 21:07 -0400
              Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-10 01:33 +0000
                Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-12 20:59 -0400
                Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-13 02:41 +0000
      Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-09 19:43 -0700
        Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-12 21:29 -0400
          Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-13 02:43 +0000
          Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-13 13:28 -0700
          Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-13 17:14 -0700
            Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-13 21:52 -0400
              Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-14 05:11 +0000
                Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-15 17:49 -0400
                Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-16 00:50 +0000
                Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-15 21:52 -0400
                Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-16 04:11 +0000
                Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-16 16:58 -0400
                Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-16 21:40 +0000
                Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-16 20:56 -0400
                Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-17 01:47 +0000
                Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-17 17:24 -0400
                Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-18 00:07 +0000
              Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-14 14:26 -0700
                Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-14 15:04 -0700
                Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-16 12:54 -0700
              Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-14 19:47 -0700
                Re: Viewing the spokes benj <nobody@gmail.com> - 2016-09-14 23:24 -0400
                Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-15 05:12 +0000
                Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-15 15:45 -0700
                Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-15 21:36 -0400
                Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-16 02:58 +0000
                Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-18 12:15 -0700
    Re: Viewing the spokes Wally W. <ww84wa@aim.com> - 2016-09-15 09:15 -0400
      Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-15 15:48 -0700
        Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-18 15:33 -0700

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