Re: Viewing the spokes

From	jimp@specsol.spam.sux.com
Newsgroups	sci.physics
Subject	Re: Viewing the spokes
Date	2016-09-13 02:41 +0000
Organization	A noiseless patient Spider
Message-ID	<8k5kad-rjs.ln1@mail.specsol.com> (permalink)
References	(4 earlier) <57d35734$0$31237$c3e8da3$dd9697d2@news.astraweb.com> <mc2cad-772.ln1@mail.specsol.com> <57d35ced$0$62038$b1db1813$2411a48f@news.astraweb.com> <uf4cad-fc2.ln1@mail.specsol.com> <57d74f6f$0$62143$b1db1813$2411a48f@news.astraweb.com>

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benj <benj@nobody.net> wrote:
> On 9/9/2016 9:33 PM, jimp@specsol.spam.sux.com wrote:
>> benj <benj@nobody.net> wrote:
>>> On 9/9/2016 8:57 PM, jimp@specsol.spam.sux.com wrote:
>>>> benj <benj@nobody.net> wrote:
>>>>> On 9/9/2016 8:10 PM, jimp@specsol.spam.sux.com wrote:
>>>>>> benj <benj@nobody.net> 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...
>>>>>>>>
>>>>>>>>
>>>>>>>>   Mark L. Fergerson
>>>>>>>>
>>>>>>> Actually, Mark, only the point of the wheel touching the ground which
>>>>>>> would be the rim is at rest. And even then that "point' will be
>>>>>>> rotating. But as we all know from the establishment science everyone
>>>>>>> here believes in, the rotation of a point particle will not produce any
>>>>>>> blurring in the camera image. OF course that "point particle" is NOT
>>>>>>> located on a spoke so for that reason your answer stands as correct.
>>>>>>
>>>>>> A point is a mathematical construct and has nothing to do with cameras
>>>>>> in the real world.
>>>>>>
>>>>>> During the time the shutter is open, EVERYTHING on the wheel is moving
>>>>>> some amount both in rotation and linearly.
>>>>>>
>>>>>> How blurred anything is depends on the rotational and linear speed of
>>>>>> the wheel relative to the view of the camera, the exposure time and the
>>>>>> resolution of the camera.
>>>>>
>>>>> We are all well aware of this jim. However the point touching the ground
>>>>> does not move linearly as I've already noted. Hence you should have said
>>>>> "rotation OR linearly" rather than "rotation and linearly".
>>>>
>>>> Set the camera exposure time to 1 hour.
>>>>
>>>> How far does the point touching the ground move in 1 hour?
>>>
>>> Doesn't move at all because if the same point is touching the ground for
>>> an hour then the wheel isn't turning very fast. In fact I say the wheel
>>> is turning extremely slowly. There goes your logic out the window.
>>
>> I did not say the same point was touching the ground for an hour.
>>
>> What I did say was that the problem depends on the rotational and linear
>> speed of the wheel relative to the view of the camera.
>>
>>> (We all observe that the angular velocity of the wheel has not been
>>> specified, right? Right.)
>>
>> OK, the angular velocity of the wheel is such that it's linear velocity
>> over the ground is equal to the field of view of the camera in 1 hour
>> and the shutter is opened when the bottom of the wheel is at the edge
>> of the field of view.
>>
>> Exposure time is still 1 hour.
>>
>> The point touching the ground appears as a steak that is the sum of the
>> exposure of the point touching the ground AND the background, whatever
>> it is.
> 
> Well, that defines things better! But interestingly enough, you must 
> agree that the GROUND will be in focus (It's not moving at all) and 
> while no "spoke" will be in focus as Sergio asked, it would appear that 
> the points on the very rim of the wheel may "sort of" be in focus as 
> they drop down to the ground, stay there for period of time and then 
> lift up. This is a lot like a scheme I invented to give depth of field 
> to microscope images. You crank through focus and the sharp parts of the 
> image register while the blurry parts just smear out and overlap and are 
> lost.

No one said anything about focus and focus is an entirely different
subject and effect than bluring due to movement.
 

-- 
Jim Pennino

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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