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Interesting problem

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  Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-26 07:05 +1000
    Re: Interesting problem Poutnik <poutnik4nntp@gmail.com> - 2016-05-25 23:17 +0200
      Re: Interesting problem "David (Time Lord) Fuller" <fuller.david@hotmail.com> - 2016-05-25 14:20 -0700
    Re: Interesting problem "David (Time Lord) Fuller" <fuller.david@hotmail.com> - 2016-05-25 14:18 -0700
    Re: Interesting problem Odd Bodkin <bodkinodd@gmail.com> - 2016-05-25 16:20 -0500
      Re: Interesting problem Tom Roberts <tjroberts137@sbcglobal.net> - 2016-05-25 18:31 -0500
      Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-27 03:25 +1000
        Re: Interesting problem Odd Bodkin <bodkinodd@gmail.com> - 2016-05-26 13:32 -0500
          Re: Interesting problem HGW <hw@...> - 2016-05-27 12:15 +1000
            Re: Interesting problem Odd Bodkin <bodkinodd@gmail.com> - 2016-05-27 04:26 -0500
              Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-27 19:52 +1000
                Re: Interesting problem Odd Bodkin <bodkinodd@gmail.com> - 2016-05-27 05:46 -0500
                  Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-27 21:55 +1000
                    Re: Interesting problem Odd Bodkin <bodkinodd@gmail.com> - 2016-05-27 07:23 -0500
                      Re: Interesting problem Odd Bodkin <bodkinodd@gmail.com> - 2016-05-27 07:26 -0500
                      Re: Interesting problem "David (Time Lord) Fuller" <fuller.david@hotmail.com> - 2016-05-27 05:29 -0700
                      Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-28 19:47 +1000
                        Re: Interesting problem Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-05-28 04:12 -0700
                          Re: Interesting problem Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-05-28 04:51 -0700
                            Re: Interesting problem alsor@interia.pl - 2016-05-28 11:27 -0700
                              Re: Interesting problem Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-05-28 14:01 -0700
                                Re: Interesting problem alsor@interia.pl - 2016-05-28 15:10 -0700
                              Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-29 09:35 +1000
                                Re: Interesting problem alsor@interia.pl - 2016-05-29 10:35 -0700
                                  Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-30 07:01 +1000
                                    Re: Interesting problem Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-05-29 15:22 -0700
                                      Re: Interesting problem alsor@interia.pl - 2016-05-30 13:05 -0700
                                    Re: Interesting problem alsor@interia.pl - 2016-05-30 16:27 -0700
                                      Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-31 20:56 +1000
                                        Re: Interesting problem alsor@interia.pl - 2016-05-31 08:40 -0700
                                          Re: Interesting problem HGW <hw@...> - 2016-06-02 09:40 +1000
                                            Re: Interesting problem alsor@interia.pl - 2016-06-02 11:53 -0700
                                      Re: Interesting problem Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-05-31 04:25 -0700
                                        Re: Interesting problem mlwozniak@wp.pl - 2016-05-31 04:58 -0700
                                          Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-06-01 06:31 +1000
                                            Re: Interesting problem Odd Bodkin <bodkinodd@gmail.com> - 2016-05-31 16:30 -0500
                                              Re: Interesting problem HGW <hw@...> - 2016-06-02 09:44 +1000
                                            Re: Interesting problem JanPB <filmart@gmail.com> - 2016-05-31 14:58 -0700
                                        Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-06-01 06:24 +1000
                                          Re: Interesting problem Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-06-01 06:23 -0700
                                            Re: Interesting problem Odd Bodkin <bodkinodd@gmail.com> - 2016-06-01 11:11 -0500
                                              Re: Interesting problem HGW <hw@...> - 2016-06-02 09:47 +1000
                                            Re: Interesting problem Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-06-01 18:50 -0700
                                              Re: Interesting problem alsor@interia.pl - 2016-06-02 12:07 -0700
                                          Re: Interesting problem alsor@interia.pl - 2016-06-01 08:59 -0700
                                            Re: Interesting problem HGW <hw@...> - 2016-06-02 10:09 +1000
                        Re: Interesting problem Odd Bodkin <bodkinodd@gmail.com> - 2016-05-29 13:52 -0500
                          Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-30 07:09 +1000
                            Re: Interesting problem Sam Wormley <swormley1@gmail.com> - 2016-05-29 16:26 -0500
                              Re: Interesting problem Fabian Russell <fb@zen.info> - 2016-05-30 04:25 +0000
                              Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-31 21:00 +1000
                                Re: Interesting problem Fabian Russell <fb@zen.info> - 2016-05-31 22:46 +0000
                                  Re: Interesting problem HGW <hw@...> - 2016-06-02 09:32 +1000
                    Re: Interesting problem Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-05-27 05:34 -0700
                      Re: Interesting problem "David (Time Lord) Fuller" <fuller.david@hotmail.com> - 2016-05-27 05:40 -0700
                        Re: Interesting problem "David (Time Lord) Fuller" <fuller.david@hotmail.com> - 2016-05-27 05:43 -0700
                      Re: Interesting problem rotchm <rotchm@gmail.com> - 2016-05-27 06:40 -0700
                        Re: Interesting problem Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-05-27 07:42 -0700
                    Re: Interesting problem rotchm <rotchm@gmail.com> - 2016-05-27 06:36 -0700
                      Re: Interesting problem Odd Bodkin <bodkinodd@gmail.com> - 2016-05-27 09:01 -0500
                        Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-28 20:04 +1000
                          Re: Interesting problem Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-05-28 04:34 -0700
      Re: Interesting problem Fabian Russell <fb@zen.info> - 2016-05-27 22:03 +0000
        Re: Interesting problem "HGWilson, DSc." <hgw@....> - 2016-05-28 20:10 +1000

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#384755

On 6/1/2016 8:23 AM, Prokaryotic Caspase Homolog wrote:
> On Tuesday, May 31, 2016 at 3:23:45 PM UTC-5, HGWilson, DSc. wrote:
>> On 31/05/16 21:25, Prokaryotic Caspase Homolog wrote:
>
>>> Henry, please try using a PROVEN solution instead of attempting to make up your
>>> own ad hoc fix. Many, many people have devoted thousands of man-years in the
>>> development of accurate, reliable and stable techniques for numerically solving
>>> differential equations.
>>
>> They didn't have double precision numbers and fast computers.
>> I have given up differential equations altogether.
>
> No you haven't. In a previous post, you wrote:
>    "In the x direction, the simplest iteration for each time unit uses
>     v=v+a: x=x+v: a= fn(x), (same for y), repeat"
>
> This is the classic Euler method for solving ordinary differential equations.
>
> The Euler method is a first order method, the simplest and most primitive.
> An easy step up would be a second order method. I'll post one for you later,
> but I have to be getting to work right now.
>
>> Real situations are
>> never exact anyway. It is much easier to simulate and produce a series
>> of graphs directly.
>>
>> I can easily correct my ellipses by doing what I just
>> suggested....monitoring the error and applying a factor throughout the
>> iteration until the error is minimized.
>
> That is pretty much what most advanced methods do: take a step, figure out
> an estimate for the error, and then take a revised step based on what you've
> found out.
>
> Later...
>

I think you're going to find that Henry's capacity or interest in doing 
anything better than what he's already done is limited at best. Henry 
complains constantly that relativity should be disparaged because it is 
more complicated than the 19th century physics he knows. Likewise, when 
it comes to computational methods, he's going to be happy with 
first-order solution plus ad hoc tweak, because anything more 
complicated than that is just above his level of commitment.

-- 
Odd Bodkin --- maker of fine toys, tools, tables

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#384804

On 02/06/16 02:11, Odd Bodkin wrote:
> On 6/1/2016 8:23 AM, Prokaryotic Caspase Homolog wrote:

>>> Real situations are
>>> never exact anyway. It is much easier to simulate and produce a series
>>> of graphs directly.
>>>
>>> I can easily correct my ellipses by doing what I just
>>> suggested....monitoring the error and applying a factor throughout the
>>> iteration until the error is minimized.
>>
>> That is pretty much what most advanced methods do: take a step, figure
>> out
>> an estimate for the error, and then take a revised step based on what
>> you've
>> found out.
>>
>> Later...
>>
>
> I think you're going to find that Henry's capacity or interest in doing
> anything better than what he's already done is limited at best. Henry
> complains constantly that relativity should be disparaged because it is
> more complicated than the 19th century physics he knows. Likewise, when
> it comes to computational methods, he's going to be happy with
> first-order solution plus ad hoc tweak, because anything more
> complicated than that is just above his level of commitment.

Coming from someone who has never produced anything useful in his life 
except a few wooden bongos and boomerangs, that is quite hilarious.

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#384814

On Wednesday, June 1, 2016 at 8:23:02 AM UTC-5, Prokaryotic Caspase Homolog wrote:
> On Tuesday, May 31, 2016 at 3:23:45 PM UTC-5, HGWilson, DSc. wrote:

> > I can easily correct my ellipses by doing what I just 
> > suggested....monitoring the error and applying a factor throughout the 
> > iteration until the error is minimized.
> 
> That is pretty much what most advanced methods do: take a step, figure out
> an estimate for the error, and then take a revised step based on what you've
> found out.
> 
> Later...

After comparing the efficiency of Euler's method versus Heun's method, I've
decided that the improvement wasn't enough to make me happy.

What I have done instead, is to refactor the RK4 code that I had shown you 
before so that it is easier to read.

Starting with x and vx, we do the following calculations:

x1 = x 
vx1 = vx 
ax1 = f(x1)

x2 = x + 0.5 * vx1 * dt
vx2 = vx + 0.5 * ax1 * dt
ax2 = f(x2)

x3 = x + 0.5 * vx2 * dt
vx3 = vx + 0.5 * ax2 * dt
ax3 = f(x3)
  
x4 = x + vx3 * dt
vx4 = vx + ax3 * dt
ay4 = f(x4)

xf = x + (dt / 6.0) * (vx1 + 2 * vx2 + 2 * vx3 + vx4)
vxf = vx + (dt / 6.0) * (ax1 + 2 * ax2 + 2 * ax3 + ax4)

x = xf
vx = vxf

We do the same for y.

Source code follows:
--------------------------------------------------------------------------------

// Runga Kutta adapted from Python code presented in
// http://doswa.com/2009/01/02/fourth-order-runge-kutta-numerical-integration.html
public override void Move()
{
    double dt = parms.secPerStep;
    double x1, y1, x2, y2, x3, y3, x4, y4;
    double vx1, vy1, vx2, vy2, vx3, vy3, vx4, vy4;
    double ax, ay, ax1, ay1, ax2, ay2, ax3, ay3, ax4, ay4;

    x1 = x; y1 = y;
    vx1 = vx; vy1 = vy;
    GetAcceleration(x1, y1, 0, 0, out ax1, out ay1);

    x2 = x + 0.5 * vx1 * dt;
    y2 = y + 0.5 * vy1 * dt;
    vx2 = vx + 0.5 * ax1 * dt;
    vy2 = vy + 0.5 * ay1 * dt;
    GetAcceleration(x2, y2, 0, 0, out ax2, out ay2);

    x3 = x + 0.5 * vx2 * dt;
    y3 = y + 0.5 * vy2 * dt;
    vx3 = vx + 0.5 * ax2 * dt;
    vy3 = vy + 0.5 * ay2 * dt;
    GetAcceleration(x3, y3, 0, 0, out ax3, out ay3);

    x4 = x + vx3 * dt;
    y4 = y + vy3 * dt;
    vx4 = vx + ax3 * dt;
    vy4 = vy + ay3 * dt;
    GetAcceleration(x4, y4, 0, 0, out ax4, out ay4);

    var xf = x + (dt / 6.0) * (vx1 + 2 * vx2 + 2 * vx3 + vx4);
    var yf = y + (dt / 6.0) * (vy1 + 2 * vy2 + 2 * vy3 + vy4);
    var vxf = vx + (dt / 6.0) * (ax1 + 2 * ax2 + 2 * ax3 + ax4);
    var vyf = vy + (dt / 6.0) * (ay1 + 2 * ay2 + 2 * ay3 + ay4);

    x = xf; y = yf;
    vx = vxf; vy = vyf;
}

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#384855

W dniu czwartek, 2 czerwca 2016 03:50:32 UTC+2 użytkownik Prokaryotic Caspase Homolog napisał:
> On Wednesday, June 1, 2016 at 8:23:02 AM UTC-5, Prokaryotic Caspase Homolog wrote:
> > On Tuesday, May 31, 2016 at 3:23:45 PM UTC-5, HGWilson, DSc. wrote:
> 
> > > I can easily correct my ellipses by doing what I just 
> > > suggested....monitoring the error and applying a factor throughout the 
> > > iteration until the error is minimized.
> > 
> > That is pretty much what most advanced methods do: take a step, figure out
> > an estimate for the error, and then take a revised step based on what you've
> > found out.
> > 
> > Later...
> 
> After comparing the efficiency of Euler's method versus Heun's method, I've
> decided that the improvement wasn't enough to make me happy.
> 
> What I have done instead, is to refactor the RK4 code that I had shown you 
> before so that it is easier to read.
> 
> Starting with x and vx, we do the following calculations:
> 
> x1 = x 
> vx1 = vx 
> ax1 = f(x1)
> 
> x2 = x + 0.5 * vx1 * dt
> vx2 = vx + 0.5 * ax1 * dt
> ax2 = f(x2)
> 
> x3 = x + 0.5 * vx2 * dt
> vx3 = vx + 0.5 * ax2 * dt
> ax3 = f(x3)
>   
> x4 = x + vx3 * dt
> vx4 = vx + ax3 * dt
> ay4 = f(x4)
> 
> xf = x + (dt / 6.0) * (vx1 + 2 * vx2 + 2 * vx3 + vx4)
> vxf = vx + (dt / 6.0) * (ax1 + 2 * ax2 + 2 * ax3 + ax4)
> 
> x = xf
> vx = vxf
> 
> We do the same for y.
> 
> Source code follows:
> --------------------------------------------------------------------------------
> 
> // Runga Kutta adapted from Python code presented in
> // http://doswa.com/2009/01/02/fourth-order-runge-kutta-numerical-integration.html
> public override void Move()
> {
>     double dt = parms.secPerStep;
>     double x1, y1, x2, y2, x3, y3, x4, y4;
>     double vx1, vy1, vx2, vy2, vx3, vy3, vx4, vy4;
>     double ax, ay, ax1, ay1, ax2, ay2, ax3, ay3, ax4, ay4;
> 
>     x1 = x; y1 = y;
>     vx1 = vx; vy1 = vy;
>     GetAcceleration(x1, y1, 0, 0, out ax1, out ay1);
> 
>     x2 = x + 0.5 * vx1 * dt;
>     y2 = y + 0.5 * vy1 * dt;
>     vx2 = vx + 0.5 * ax1 * dt;
>     vy2 = vy + 0.5 * ay1 * dt;
>     GetAcceleration(x2, y2, 0, 0, out ax2, out ay2);
> 
>     x3 = x + 0.5 * vx2 * dt;
>     y3 = y + 0.5 * vy2 * dt;
>     vx3 = vx + 0.5 * ax2 * dt;
>     vy3 = vy + 0.5 * ay2 * dt;
>     GetAcceleration(x3, y3, 0, 0, out ax3, out ay3);
> 
>     x4 = x + vx3 * dt;
>     y4 = y + vy3 * dt;
>     vx4 = vx + ax3 * dt;
>     vy4 = vy + ay3 * dt;
>     GetAcceleration(x4, y4, 0, 0, out ax4, out ay4);
> 
>     var xf = x + (dt / 6.0) * (vx1 + 2 * vx2 + 2 * vx3 + vx4);
>     var yf = y + (dt / 6.0) * (vy1 + 2 * vy2 + 2 * vy3 + vy4);
>     var vxf = vx + (dt / 6.0) * (ax1 + 2 * ax2 + 2 * ax3 + ax4);
>     var vyf = vy + (dt / 6.0) * (ay1 + 2 * ay2 + 2 * ay3 + ay4);
> 
>     x = xf; y = yf;
>     vx = vxf; vy = vyf;
> }

I even don't try to analise this improvisation...

The RK4 metod for n-body problem looks that:

void RK4()
{
     h = dt;
     h2 = h*f_half;

//   r1 = r; v1 = v;
     force(a,y,nB);  // a1 = a(x1, v1, 0)
     copy(yi, y); // some copy of data...

 //   r2 = r + v1*h2; v2 = v + a1*h2;
     for(int i = 0; i < nB; i++)
      {
         yi[i].r.addm(y[i].v, h2);
         yi[i].v.addm(a[i],   h2);
         
         addm(ys[i].r, y[i].v, yi[i].v, 2); // v1 + 2v2
         ys[i].v = a[i]; // a1
      }

     force(a, yi, nB);

//   r3 = r + v2*h2; v3 = v + a2*h2;
     for(int i = 0; i < nB; i++)
      {
         addm(yi[i].r, y[i].r, yi[i].v, h2);
         addm(yi[i].v, y[i].v, a[i],   h2);

         ys[i].r.addm(yi[i].v, 2); //  2v3
         ys[i].v.addm(a[i],    2); // 2a2
      }

     force(a, yi, nB);

//   r4 = r + v3*h; v4 = v + a3*h;

     for(int i = 0; i < nB; i++)
      {
         addm(yi[i].r, y[i].r, yi[i].v, h);
         addm(yi[i].v, y[i].v, a[i],   h);

         ys[i].r.add(yi[i].v); //  v4
         ys[i].v.addm(a[i], 2); // 2a3
      }

     force(a, yi, nB);

     for(int i = 0; i < nB; i++)
      {
         ys[i].v.add(a[i]); // a4
      }

      //  r += (h/6)*(v1 + 2*v2 + 2*v3 + v4);
      //  v += (h/6)*(a1 + 2*a2 + 2*a3 + a4);
      addm(y, ys, nB, h/6);
}

simply and fast.

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#384754

W dniu wtorek, 31 maja 2016 22:23:45 UTC+2 użytkownik HGWilson, DSc. napisał:

> I can easily correct my ellipses by doing what I just 
> suggested....monitoring the error and applying a factor throughout the 
> iteration until the error is minimized.

Indeed. This is just the method which Einstein used to produce the GR. :)
 
Simply:
the discovered correction for the newtonian force is:
3v_t^2/c^2,

so, then just use it, and You get the correct precession for Mercury...

g(r) = -GM/r^2 r^0; this is newtonian force/accel.

g'(r) = -GM/r^2 (1 + 3vt^2/c^2) * r^0 ; this is the discovered by Einstein.

where:
v^2 = vr^2 + vt^2 => v_t^2 = v^2 - v_r^2

and we know: |vr| = v*r^0, thus:
vr^2 = |vr|^2 = [(v.r)/|r|]^2

which is easy to compute:

v.r is a scalar product of vectors: v.r = vx*rx + vy*ry + ...
v^2 = v.v; r^2 = r.r;

finally:
v_t^2 = v.v - (v.r)^2/(r.r); 
very simple and fast...

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#384806

On 02/06/16 01:59, alsor@interia.pl wrote:
> W dniu wtorek, 31 maja 2016 22:23:45 UTC+2 użytkownik HGWilson, DSc. napisał:
>
>> I can easily correct my ellipses by doing what I just
>> suggested....monitoring the error and applying a factor throughout the
>> iteration until the error is minimized.
>
> Indeed. This is just the method which Einstein used to produce the GR. :)

It is pretty well what Planck did too when he matched the black body 
radiation curve. ..but in that case I think the correct theory followed.

> Simply:
> the discovered correction for the newtonian force is:
> 3v_t^2/c^2,

Where and why was that discovered and proved?

>
> so, then just use it, and You get the correct precession for Mercury...
>
> g(r) = -GM/r^2 r^0; this is newtonian force/accel.
>
> g'(r) = -GM/r^2 (1 + 3vt^2/c^2) * r^0 ; this is the discovered by Einstein.
>
> where:
> v^2 = vr^2 + vt^2 => v_t^2 = v^2 - v_r^2

sorry, I cant follow that...what is v_t or vt?

> and we know: |vr| = v*r^0, thus:
> vr^2 = |vr|^2 = [(v.r)/|r|]^2
>
> which is easy to compute:
>
> v.r is a scalar product of vectors: v.r = vx*rx + vy*ry + ...
> v^2 = v.v; r^2 = r.r;
>
> finally:
> v_t^2 = v.v - (v.r)^2/(r.r);
> very simple and fast...

I get it...

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#384566

On 5/28/2016 4:47 AM, HGWilson, DSc. wrote:
> On 27/05/16 22:23, Odd Bodkin wrote:
>> On 5/27/2016 6:55 AM, HGWilson, DSc. wrote:
>>> On 27/05/16 20:46, Odd Bodkin wrote:
>>>> On 5/27/2016 4:52 AM, HGWilson, DSc. wrote:
>>>>> On 27/05/16 19:26, Odd Bodkin wrote:
>>>
>>>>>>
>>>>>> Do you know the relationship between the number of solar days and the
>>>>>> number of sidereal days in a year?
>>>>>
>>>>> Of course. Why don't you tell Poutnik.
>>>>>
>>>>
>>>> Why don't YOU tell Poutnik? Be sure to use the relationship between
>>>> solar and sidereal days in your argument with him about it.
>>>
>>> Poutnik's answer was 99. Is he right?
>>
>> I see you're having trouble making the connection.
>> I'll give you another example that will help you visualize what's
>> going on.
>> Let's say you have a gear that has 100 shallow teeth on its
>> circumference. There is a red line painted along a radius of the gear.
>> Now you're going to put that inside a circular ring with just a slightly
>> larger inner diameter, and which has 101 shallow teeth on its inner
>> perimeter.
>
> Bodkin, I have asked the question. you are obviously having trouble
> understanding it. Let's say there are 1000 teeth on the rack and 10 on
> the pinion.

And so you're having problems getting my related problem, which is even 
EASIER to see the answer to? And from this you can't see the answer to 
your problem?

>
>> Now I'm going to use my finger to run that gear around inside the ring,
>> once around the inner perimeter of the ring. When I do that, how many
>> revolutions will that red line on the gear have made? And if I ran the
>> gear clockwise around the inner perimeter of the ring, in which
>> direction will the red line rotate?
>
> Bodkin, repeating my question is not answering it. I know the
> answer..you obviously  do not. You probably agree with Poutnik.
>>
>
>>
>


-- 
Odd Bodkin --- maker of fine toys, tools, tables

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#384575

On 30/05/16 04:52, Odd Bodkin wrote:
> On 5/28/2016 4:47 AM, HGWilson, DSc. wrote:

>>>>> Why don't YOU tell Poutnik? Be sure to use the relationship between
>>>>> solar and sidereal days in your argument with him about it.
>>>>
>>>> Poutnik's answer was 99. Is he right?
>>>
>>> I see you're having trouble making the connection.
>>> I'll give you another example that will help you visualize what's
>>> going on.
>>> Let's say you have a gear that has 100 shallow teeth on its
>>> circumference. There is a red line painted along a radius of the gear.
>>> Now you're going to put that inside a circular ring with just a slightly
>>> larger inner diameter, and which has 101 shallow teeth on its inner
>>> perimeter.
>>
>> Bodkin, I have asked the question. you are obviously having trouble
>> understanding it. Let's say there are 1000 teeth on the rack and 10 on
>> the pinion.
>
> And so you're having problems getting my related problem, which is even
> EASIER to see the answer to? And from this you can't see the answer to
> your problem?

Read Fabian Russell's post.....it's good.

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#384576

On 5/29/16 4:09 PM, HGWilson, DSc. wrote:
> Read Fabian Russell's post.....it's good.

   What point was made in said post that you liked?


-- 

sci.physics is an unmoderated newsgroup dedicated
to the discussion of physics, news from the physics
community, and physics-related social issues.

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#384588

On Sun, 29 May 2016 16:26:40 -0500, Sam Wormley wrote:

> 
>    What point was made in said post that you liked?
>

Sammy thinks he's a button on Facebook or other populistic
junk site.

But we have a question for Sammy.

If we consider ANY closed curve in the plane with the same
length as our straight line segment, how does the circle behave
as it rolls along this curve, either on the inside or outside?

Note that the shape of curve can be of any complexity.  If the
rolling circle does not "fit" in some places, we can allow the
circle to "pass through" the curve so that its radius chord is
always normal to the curve as is rolls.

What says Sammy>

Sammy: He was named after the prophet, so why doesn't he act
like one?

LOL!

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#384638

On 30/05/16 07:26, Sam Wormley wrote:
> On 5/29/16 4:09 PM, HGWilson, DSc. wrote:
>> Read Fabian Russell's post.....it's good.
>
> What point was made in said post that you liked?

It actually understood my question and discussed the science
sensibly...which is more than you have been able to do in many years.

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#384706

On Tue, 31 May 2016 21:00:04 +1000, HGWilson, DSc. wrote:

> 
> which is more than you have been able to do in many years.
>

The problem actually falls under the lame category of
"trick question," or deceptive "word problem."  It is
of great interest only to charlatans and quacks.

The "naive" answer remains absolutely correct.  That is,
there is no change in the mapping of the circumference
of the rolling circle to the original line segment.

The apparent "paradox" occurs only because there are
TWO kinds of unrelated motion involved and that motion
mixture is concealed by the wording.

I do not like "trick questions" and those who bother
to introduce them. 

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#384800

On 01/06/16 08:46, Fabian Russell wrote:
> On Tue, 31 May 2016 21:00:04 +1000, HGWilson, DSc. wrote:
>
>>
>> which is more than you have been able to do in many years.
>>
>
> The problem actually falls under the lame category of
> "trick question," or deceptive "word problem."  It is
> of great interest only to charlatans and quacks.

gawd! another 'know-all' idiot....we have enough here already thank you.

> The "naive" answer remains absolutely correct.  That is,
> there is no change in the mapping of the circumference
> of the rolling circle to the original line segment.
>
> The apparent "paradox" occurs only because there are
> TWO kinds of unrelated motion involved and that motion
> mixture is concealed by the wording.

Whatever it is that you are trying to say is certainly concealed by your 
inadequate wording.

> I do not like "trick questions" and those who bother
> to introduce them.

It is not a trick question. Try proving how and why the wheel makes an 
extra rotation as it rolls around the outside of a circular rack....or 
how it rotates when taken around any circular path. It is not obvious.
The wheel can follow the same path without rotating at all.

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#384395

On Friday, May 27, 2016 at 6:55:02 AM UTC-5, HGWilson, DSc. wrote:

> Poutnik's answer was 99. Is he right?

Is the gearwheel rolling on the outside or the inside of the circle?
It makes a difference whether the revolutions have the same sense or the
opposite sense as the rotations.

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#384398

7:34 AMProkaryotic Caspase Homolog
On Friday, May 27, 2016 at 6:55:02 AM UTC-5, HGWilson, DSc. wrote: 

> Poutnik's answer was 99. Is he right? 

Is the gearwheel rolling on the outside or the inside of the circle? 
It makes a difference whether the revolutions have the same sense or the 
opposite sense as the rotations. 

200/(99+51)
Modulo 200

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#384399

(1 / gravitational constant) / the speed of light =
49.9790376

1 =/= 1
1 = 49.9790376

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#384406

On Friday, May 27, 2016 at 8:34:12 AM UTC-4, Prokaryotic Caspase Homolog wrote:
 
> Is the gearwheel rolling on the outside or the inside of the circle?

Inside.

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#384410

Unspecified in the original problem statement.

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#384405

On Friday, May 27, 2016 at 7:55:02 AM UTC-4, HGWilson, DSc. wrote:
 
> Poutnik's answer was 99. Is he right?

Yes. Thats what you were waiting for? That some of us give the same answers so that *you* can steal the answer and claim that you knew it all the long... ?
We know your tactics...you remain true to yourself!

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#384407

On 5/27/2016 8:36 AM, rotchm wrote:
> On Friday, May 27, 2016 at 7:55:02 AM UTC-4, HGWilson, DSc. wrote:
>
>> Poutnik's answer was 99. Is he right?
>
> Yes. Thats what you were waiting for? That some of us give the same answers so
> that *you* can steal the answer and claim that you knew it all the long... ?

Well, he'll do that only after having done an all-caps derisive response 
to the correct answer.
Maybe if he's embarrassed, he'll say, "I was only testing your conviction."

> We know your tactics...you remain true to yourself!

Or he can buy a Spirograph, a toy for children that gives the answer, 
and so which children can answer correctly. This is why I commented that 
he seems to be amused (and flummoxed) by children's problems.


-- 
Odd Bodkin --- maker of fine toys, tools, tables

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