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Groups > sci.physics > #595068 > unrolled thread
| Started by | Sergio <invalid@invalid.com> |
|---|---|
| First post | 2016-08-29 12:08 -0500 |
| Last post | 2016-09-18 15:33 -0700 |
| Articles | 16 on this page of 76 — 12 participants |
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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
Page 4 of 4 — ← Prev page 1 2 3 [4]
| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2016-09-17 01:47 +0000 |
| Message-ID | <dvjuad-kq4.ln1@mail.specsol.com> |
| In reply to | #597262 |
benj <benj@nobody.net> wrote: > On 9/16/2016 5:40 PM, jimp@specsol.spam.sux.com wrote: >> benj <benj@nobody.net> wrote: >>> On 9/16/2016 12:11 AM, jimp@specsol.spam.sux.com wrote: >>>> benj <benj@nobody.net> wrote: >>>>> On 9/15/2016 8:50 PM, jimp@specsol.spam.sux.com wrote: >>>> >>>> <snip> >>>> >>>>>> Instantaneous only appears in mathematical equations, not in camera >>>>>> exposures. >>>>> >>>>> Actually not true, >>>> >>>> Yes true. >>>> >>>>> because there will be a LINE of point right along the >>>> >>>> A line and a point are two different things. >>>> >>>>> ground the camera sees that are not moving. Of course since the wheel is >>>>> passing through the frame these exposures will be less than that set by >>>>> the camera shutter, but film speed and exposure were not specified. >>>>> Excuse me, nobody knows what film is any more, Lets just say the photo >>>>> array automatically adjusts it's exposure, OK? >>>> >>>> Gibbering nonsense. >>>> >>>> There are no "these exposures", there is only one exposure during the >>>> time the shutter is open. >>> >>> Drooling senile nonsense. When the image moves in the frame it is no >>> longer exposing the sensor. >> >> Drooling senile nonsense. > > No imagination. Plagiarism. > >> The image is exposed the entire time the shutter is open, which means >> the final image is the sum of whatever happed during the exposure time. > > Drooling nonsense. Set up your 4x5 press camera. Focus on a road. A car > comes down the road. Stops in front of the camera for a minute. Then > goes on. What is the exposure time of the car? Is it the whole time the > shutter was open? You need to quite before you embarrass yourself further. The image is exposed the entire time the shutter is open, which means the final image is the sum of whatever happened during the exposure time. Therefor the final image in your example will be primarily the background mixed with the streak of the moving car on either side of what will be primarily the car mixed with the background. You lost this silly argument long ago due to your utter lack of understanding the basics of imaging. <snip remaining silly name calling, dick waving, and drool> -- Jim Pennino
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| From | benj <benj@nobody.net> |
|---|---|
| Date | 2016-09-17 17:24 -0400 |
| Message-ID | <57ddb490$0$62163$b1db1813$2411a48f@news.astraweb.com> |
| In reply to | #597268 |
On 9/16/2016 9:47 PM, jimp@specsol.spam.sux.com wrote: > benj <benj@nobody.net> wrote: >> On 9/16/2016 5:40 PM, jimp@specsol.spam.sux.com wrote: >>> benj <benj@nobody.net> wrote: >>>> On 9/16/2016 12:11 AM, jimp@specsol.spam.sux.com wrote: >>>>> benj <benj@nobody.net> wrote: >>>>>> On 9/15/2016 8:50 PM, jimp@specsol.spam.sux.com wrote: >>>>> >>>>> <snip> >>>>> >>>>>>> Instantaneous only appears in mathematical equations, not in camera >>>>>>> exposures. >>>>>> >>>>>> Actually not true, >>>>> >>>>> Yes true. >>>>> >>>>>> because there will be a LINE of point right along the >>>>> >>>>> A line and a point are two different things. >>>>> >>>>>> ground the camera sees that are not moving. Of course since the wheel is >>>>>> passing through the frame these exposures will be less than that set by >>>>>> the camera shutter, but film speed and exposure were not specified. >>>>>> Excuse me, nobody knows what film is any more, Lets just say the photo >>>>>> array automatically adjusts it's exposure, OK? >>>>> >>>>> Gibbering nonsense. >>>>> >>>>> There are no "these exposures", there is only one exposure during the >>>>> time the shutter is open. >>>> >>>> Drooling senile nonsense. When the image moves in the frame it is no >>>> longer exposing the sensor. >>> >>> Drooling senile nonsense. >> >> No imagination. Plagiarism. >> >>> The image is exposed the entire time the shutter is open, which means >>> the final image is the sum of whatever happed during the exposure time. >> >> Drooling nonsense. Set up your 4x5 press camera. Focus on a road. A car >> comes down the road. Stops in front of the camera for a minute. Then >> goes on. What is the exposure time of the car? Is it the whole time the >> shutter was open? You need to quite before you embarrass yourself further. > > The image is exposed the entire time the shutter is open, which means > the final image is the sum of whatever happened during the exposure time. > > Therefor the final image in your example will be primarily the background > mixed with the streak of the moving car on either side of what will be > primarily the car mixed with the background. > > You lost this silly argument long ago due to your utter lack of understanding > the basics of imaging. > > <snip remaining silly name calling, dick waving, and drool> Please explain the difference between the image of moving objects taken with a blade shutter and the same situation taken with a focal plane shutter. Not the same are they? I think everybody gets your message that you are very very smart and everyone else is very very stooopid.
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2016-09-18 00:07 +0000 |
| Message-ID | <9f21bd-a6d.ln1@mail.specsol.com> |
| In reply to | #597336 |
benj <benj@nobody.net> wrote: > On 9/16/2016 9:47 PM, jimp@specsol.spam.sux.com wrote: >> benj <benj@nobody.net> wrote: >>> On 9/16/2016 5:40 PM, jimp@specsol.spam.sux.com wrote: >>>> benj <benj@nobody.net> wrote: >>>>> On 9/16/2016 12:11 AM, jimp@specsol.spam.sux.com wrote: >>>>>> benj <benj@nobody.net> wrote: >>>>>>> On 9/15/2016 8:50 PM, jimp@specsol.spam.sux.com wrote: >>>>>> >>>>>> <snip> >>>>>> >>>>>>>> Instantaneous only appears in mathematical equations, not in camera >>>>>>>> exposures. >>>>>>> >>>>>>> Actually not true, >>>>>> >>>>>> Yes true. >>>>>> >>>>>>> because there will be a LINE of point right along the >>>>>> >>>>>> A line and a point are two different things. >>>>>> >>>>>>> ground the camera sees that are not moving. Of course since the wheel is >>>>>>> passing through the frame these exposures will be less than that set by >>>>>>> the camera shutter, but film speed and exposure were not specified. >>>>>>> Excuse me, nobody knows what film is any more, Lets just say the photo >>>>>>> array automatically adjusts it's exposure, OK? >>>>>> >>>>>> Gibbering nonsense. >>>>>> >>>>>> There are no "these exposures", there is only one exposure during the >>>>>> time the shutter is open. >>>>> >>>>> Drooling senile nonsense. When the image moves in the frame it is no >>>>> longer exposing the sensor. >>>> >>>> Drooling senile nonsense. >>> >>> No imagination. Plagiarism. >>> >>>> The image is exposed the entire time the shutter is open, which means >>>> the final image is the sum of whatever happed during the exposure time. >>> >>> Drooling nonsense. Set up your 4x5 press camera. Focus on a road. A car >>> comes down the road. Stops in front of the camera for a minute. Then >>> goes on. What is the exposure time of the car? Is it the whole time the >>> shutter was open? You need to quite before you embarrass yourself further. >> >> The image is exposed the entire time the shutter is open, which means >> the final image is the sum of whatever happened during the exposure time. >> >> Therefor the final image in your example will be primarily the background >> mixed with the streak of the moving car on either side of what will be >> primarily the car mixed with the background. >> >> You lost this silly argument long ago due to your utter lack of understanding >> the basics of imaging. >> >> <snip remaining silly name calling, dick waving, and drool> > > Please explain the difference between the image of moving objects taken > with a blade shutter and the same situation taken with a focal plane > shutter. Not the same are they? I think everybody gets your message that > you are very very smart and everyone else is very very stooopid. I've never heard of a "blade shutter" and even looked up shutters to see if it was something I had missed; it was not. https://en.wikipedia.org/wiki/Shutter_(photography) FYI all mechanical shutters have blades of one sort or another. I think everybody gets your message that you are making shit up as you go along. -- Jim Pennino
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| From | noTthaTguY <abu.kuanysh05@gmail.com> |
|---|---|
| Date | 2016-09-14 14:26 -0700 |
| Message-ID | <6f0eb900-91b2-4c33-946b-6ede320fc8cc@googlegroups.com> |
| In reply to | #596893 |
if you galilean frame de reference is taken as stationary with respect to the contact > Ahem. So lesse if I got your "logic" here. The ground is stationary. We > agree with that, right? And the rim of the wheel has points that contact > the ground. But no points on the wheel are stationary? So you are > arguing that the wheel is sliding? > > >> 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? Or is > sliding. > > > Mark L. Fergerson > >
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| From | noTthaTguY <abu.kuanysh05@gmail.com> |
|---|---|
| Date | 2016-09-14 15:04 -0700 |
| Message-ID | <f7447680-9c60-40f3-ab9f-bcb7fb812cf8@googlegroups.com> |
| In reply to | #596974 |
what is the minimum number of spokes, in hte standard 36-spoke bicycle wheel, and can it be done symmetrically > if you galilean frame de reference is taken as stationary > with respect to the contact
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| From | noTthaTguY <abu.kuanysh05@gmail.com> |
|---|---|
| Date | 2016-09-16 12:54 -0700 |
| Message-ID | <22ab5c9e-e900-4ddd-8b30-691a253db1f3@googlegroups.com> |
| In reply to | #596982 |
what power, is e to the e, between > what is the minimum number of spokes, > in the standard 36-spoke bicycle wheel, and > can it be done symmetrically
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| From | "nuny@bid.nes" <Alien8752@gmail.com> |
|---|---|
| Date | 2016-09-14 19:47 -0700 |
| Message-ID | <71dafec9-ab24-4f4e-86f8-bdb115967655@googlegroups.com> |
| In reply to | #596893 |
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. > 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. > But no points on the wheel are stationary? The wheel is *moving* WRT the camera. By definition no part of it can be stationary. > So you are arguing that the wheel is sliding? No, it was stipulated to be rolling. You keep taking "in contact with the ground" to be equal to "stationary". This is false. > >> 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? Mark L. Fergerson
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| From | benj <nobody@gmail.com> |
|---|---|
| Date | 2016-09-14 23:24 -0400 |
| Message-ID | <57da146e$0$30254$b1db1813$79461190@news.astraweb.com> |
| In reply to | #597000 |
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? >> 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. >>>> 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) > > Mark L. Fergerson >
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2016-09-15 05:12 +0000 |
| Message-ID | <36npad-llh.ln1@mail.specsol.com> |
| In reply to | #597004 |
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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| From | "nuny@bid.nes" <Alien8752@gmail.com> |
|---|---|
| Date | 2016-09-15 15:45 -0700 |
| Message-ID | <f8add105-8b22-4d5a-a262-73e24f1d1e32@googlegroups.com> |
| In reply to | #597004 |
On Wednesday, September 14, 2016 at 8:40:55 PM UTC-7, benj 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? I don't care what other people believe. The posed problem is about an actual physical wheel actually rolling on the actual physical ground while an actual physical camera takes a picture of it with a nonzero exposure time. Reducing the contact patch to a point should make the issue clearer, but somehow you've managed to perceive it as more confusing. > >> 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. Backwards with respect to the axis of the wheel, yes, but not the ground and camera. Look up "cycloid". Te camera will not see any point on the wheel as moving backward. > 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? No, we do not. > >> 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. Think about that for a moment. If the contact "point" of a rolling wheel stays in contact with the ground, the wheel can't move. > In which case it must be stationary. And therefore the entire wheel is stationary, which denies one condition of the original problem. > >>>> 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 I do understand the details of the problem. Mark L. Fergerson
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| From | benj <benj@nobody.net> |
|---|---|
| Date | 2016-09-15 21:36 -0400 |
| Message-ID | <57db4c9e$0$4553$c3e8da3$b280bf18@news.astraweb.com> |
| In reply to | #597098 |
On 9/15/2016 6:45 PM, nuny@bid.nes wrote: > On Wednesday, September 14, 2016 at 8:40:55 PM UTC-7, benj 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? > > I don't care what other people believe. Not much of a herd animal, I'm sorry to say. > The posed problem is about an actual physical wheel actually rolling > on the actual physical ground while an actual physical camera takes a > picture of it with a nonzero exposure time. > > Reducing the contact patch to a point should make the issue clearer, > but somehow you've managed to perceive it as more confusing. Well, now isn't that the difference between physics and engineering? >>>> 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. > > Backwards with respect to the axis of the wheel, yes, but not the > ground and camera. True. > Look up "cycloid". Why? not that Note that the cycloid has a point that touches the ground, hence can't be moving. > Te camera will not see any point on the wheel as moving backward. True. But will see an array of points as standing still. >> 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? > > No, we do not. :-) Not much into science theory, eh? >>>> 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. > > Think about that for a moment. If the contact "point" of a rolling > wheel stays in contact with the ground, the wheel can't move. Who said it "stays" there? It's quickly replaced by another stationary point! >> In which case it must be stationary. > > And therefore the entire wheel is stationary, which denies one > condition of the original problem. No. >>>>>> 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 > > I do understand the details of the problem. Then why do you insist that points touching the ground are moving? > Mark L. Fergerson >
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2016-09-16 02:58 +0000 |
| Message-ID | <8o3sad-aop.ln1@mail.specsol.com> |
| In reply to | #597110 |
benj <benj@nobody.net> wrote: <snip> > Why? not that Note that the cycloid has a point that touches the ground, > hence can't be moving. Bloody nonsense. Note that the x position of a cycloid for any delta t greater than zero is always increasing. The cusps in the x position are instantaneous values which only exist mathematically and NOT during any real time period, i.e. a camera exposure time. >> Te camera will not see any point on the wheel as moving backward. > > True. But will see an array of points as standing still. Nope, a continuous multiple exposure line with no discrete points. <snip rest of idiocy> -- Jim Pennino
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| From | "nuny@bid.nes" <Alien8752@gmail.com> |
|---|---|
| Date | 2016-09-18 12:15 -0700 |
| Message-ID | <43a70398-ae48-4f8e-a4c2-5091df495e7f@googlegroups.com> |
| In reply to | #597110 |
On Thursday, September 15, 2016 at 7:16:47 PM UTC-7, benj wrote: > On 9/15/2016 6:45 PM, nuny@bid.nes wrote: > > On Wednesday, September 14, 2016 at 8:40:55 PM UTC-7, benj 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? > > > > I don't care what other people believe. > > Not much of a herd animal, I'm sorry to say. > > > The posed problem is about an actual physical wheel actually rolling > > on the actual physical ground while an actual physical camera takes a > > picture of it with a nonzero exposure time. > > > > Reducing the contact patch to a point should make the issue clearer, > > but somehow you've managed to perceive it as more confusing. > > Well, now isn't that the difference between physics and engineering? No. Engineering can't happen without physics, but physics without at least attempting to engineer an experiment is mere philosophizing. Philosophical abstracts like dimensionless points and instantaneity are unphysical. That's why they're called "abstract". > >>>> 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. > > > > Backwards with respect to the axis of the wheel, yes, but not the > > ground and camera. > > True. Then you agree there is no actual, physical, backwards motion. > > Look up "cycloid". > > Why? not that Note that the cycloid has a point that touches the ground, > hence can't be moving. Sigh. How long does it remain in contact with the ground? > > Te camera will not see any point on the wheel as moving backward. > > True. But will see an array of points as standing still. Take a camera and shoot a brief video of a rolling wheel. Show me your "line of points". > >> 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? > > > > No, we do not. > > :-) Not much into science theory, eh? You agreed above there was no backward motion, so there's no "cancellation". > >>>> 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. > > > > Think about that for a moment. If the contact "point" of a rolling > > wheel stays in contact with the ground, the wheel can't move. > > Who said it "stays" there? It's quickly replaced by another stationary > point! Then there's no time for it to be stationary. > >> In which case it must be stationary. > > > > And therefore the entire wheel is stationary, which denies one > > condition of the original problem. > > No. Oh, so now the wheel is flexible, so that one point on it can be stationary while the rest 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 > > > > I do understand the details of the problem. > > Then why do you insist that points touching the ground are moving? Why do you insist the contact patch/point is stationary when it's part of a moving object? Mark L. Fergerson
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| From | Wally W. <ww84wa@aim.com> |
|---|---|
| Date | 2016-09-15 09:15 -0400 |
| Message-ID | <pf7ltb1c74llltola17oscbpnbouf13ath@4ax.com> |
| In reply to | #596380 |
On Fri, 9 Sep 2016 09:08:14 -0700 (PDT), 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 Agreed, everything moves during the finite time the shutter is open. Still, "instant centers" is a well worn concept in kinematics: http://ocw.mit.edu/courses/mechanical-engineering/2-003j-dynamics-and-control-i-spring-2007/lecture-notes/lec08.pdf Figure 3: A disk with radius R rolls angular velocity omega in x-direction. Point I marks the contact with disk and ground: no slip, not moving for an instant because ground is still. Instant center.
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| From | "nuny@bid.nes" <Alien8752@gmail.com> |
|---|---|
| Date | 2016-09-15 15:48 -0700 |
| Message-ID | <9a9acf6e-015f-4a09-acc8-bd0d68cb9260@googlegroups.com> |
| In reply to | #597033 |
On Thursday, September 15, 2016 at 6:14:59 AM UTC-7, Wally W. wrote: > On Fri, 9 Sep 2016 09:08:14 -0700 (PDT), 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... > > Agreed, everything moves during the finite time the shutter is open. > > Still, "instant centers" is a well worn concept in kinematics: > http://ocw.mit.edu/courses/mechanical-engineering/2-003j-dynamics-and-control-i-spring-2007/lecture-notes/lec08.pdf > Figure 3: A disk with radius R rolls angular velocity omega in > x-direction. > > Point I marks the contact with disk and ground: no slip, not moving > for an instant because ground is still. Instant center. And that's Benj's problem. He's conflating theory with practice. There is no "instant" given a nonzero shutter speed. Mark L. Fergerson
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| From | noTthaTguY <abu.kuanysh05@gmail.com> |
|---|---|
| Date | 2016-09-18 15:33 -0700 |
| Message-ID | <9cad910d-a0fa-4d84-8fce-4a59670751de@googlegroups.com> |
| In reply to | #597099 |
if you don't delete this message, it will still be on that thing ... some tradEName, or what ever > And that's Benj's problem. He's conflating theory with practice. There is no "instant" given a nonzero shutter speed. > > > Mark L. Fergerson
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