On Saturday, April 16, 2022 at 2:04:46 PM UTC-7, Mason Urogataya wrote:
> RichD wrote:
>
> >>> If a wheel has tangential speed v, this *means* that relative to the
> >>> center of the wheel the top of the wheel has speed v in one direction,
> >>> Now map that with a Galilean transform to a frame To first order, the
> >>> deformation of the tire doesn’t affect the friction at all.
> >>
> >> Although it may seem contradictory, the patch of the tire has static
> >> friction with the road. This is because the patch is stationary
> >> relative to the road.
> >
> > Quite.
> > The tire moves due to the static coefficient friction. No different
> > than pushing with the sole of your shoe.
> all three wrong. The top of the tire has the speed 2v, and ideally there
> should be no friction, but static point applied force.

Rotation is not a relative. The Earth's round motion
creates the sky moving opposite. Is that relative
comparison?

Mitchell Raemsch

RichD <r_delaney2001@yahoo.com> wrote:
> On April 15, Michael Moroney wrote:
>> On 4/15/2022, Odd Bodkin wrote:
>>> The wheel cannot *accelerate* without the application of friction force
>>> between the tire patch and the road.
>>> The wheel can “progress” at constant speed with or without friction.
>>> Anybody who has rolled a smooth, hard ball on smooth ice knows that the
>>> ball will “progress”
>>> If a wheel has tangential speed v, this *means* that relative to the center
>>> of the wheel the top of the wheel has speed v in one direction,
>>> Now map that with a Galilean transform to a frame
>>> To first order, the deformation of the tire doesn’t affect the friction at all.
>>
>> Although it may seem contradictory, the patch of
>> the tire has static friction with the road. This is because the patch
>> is stationary relative to the road.

Yes.

>
> Quite.
> The tire moves due to the static coefficient friction. No
> different than pushing with the sole of your shoe.

Yes, which is important if you want to accelerate or change direction.
Notice the friction is not needed for continued motion. Anyone who has slid
down an icy sidewalk with their legs held rigid knows this.

>
> Notice that this trivial observation is typical of Bod. He's
> such a scatterbrain, he never offers anything other than
> the laughably wrong, or trivially true.
>
> He dredges up random jargon and memories of 11th grade
> physics (one of his obsessions), mashes them, tosses them
> into the stew, and believes he's contributed to the meal.
>
> I wouldn't say he makes too many errors to bother correcting.
> Rather, his brain fragments like Humpty Dumpty, one can't put
> him back together.
>
> Look at the stuff quoted above:
> Galilean transform;
> static and rolling resistance;
> ice is frictionless (who woulda thunk?)
> the wheel has tangential speed, relative to the axle;
> the bike moves forward;
> when the wheel starts moving, it accelerates, wow!

Well, it’s a shame you got confused about the basics.

Would you like to go back to simpler examples that might be easier for you
to follow?

>
> And - of course - not one of these 'thoughts' address
> the question. He set a new standard in this thread, I doubt
> he'll ever top it -
>
> --
> Rich
>

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

On April 17, bodk...@gmail.com wrote:
>>> Although it may seem contradictory, the patch of
>>> the tire has static friction with the road.

It isn't contradictory to anyone but you.

> This is because the patch is stationary relative to the road.

Reversal of cause and effect.
Typical.

> Well, it’s a shame you got confused about the basics.
> Would you like to go back to simpler examples that might be easier for you
> to follow?

No.
Not everyone shares your fixation on 11th grade physics.

--
Rich

RichD wrote:

>> Well, it’s a shame you got confused about the basics.
>> Would you like to go back to simpler examples that might be easier for
>> you to follow?
>
> No. Not everyone shares your fixation on 11th grade physics.

yes, sure, they don't even have a rocket bringing them 2 metres into the
space, then they still want the people believe the landed on the moon, a
century ago.

RichD <r_delaney2001@yahoo.com> wrote:
> On April 17, bodk...@gmail.com wrote:
>>>> Although it may seem contradictory, the patch of
>>>> the tire has static friction with the road.
>
> It isn't contradictory to anyone but you.

It’s not contradictory to me. I didn’t say the line above.

>
>> This is because the patch is stationary relative to the road.
>
> Reversal of cause and effect.
> Typical.

You snipped the effect, no way to evaluate what you’re complaining about.

>
>> Well, it’s a shame you got confused about the basics.
>> Would you like to go back to simpler examples that might be easier for you
>> to follow?
>
> No.
> Not everyone shares your fixation on 11th grade physics.
>

Well, it’s going to be tricky for you to have any coherent thoughts on more
advanced physics if you don’t get the 11th grade physics right.

Remember when you thought runners landed their front foot on the road with
the foot having horizontal motion, so that the toes would slide forward in
the shoe’s toe box and jam the front of the toes, and there would be
skidding wear on the bottom of shoes, and knee and ankle joints would get
worn from running?

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

On April 18, bodk...@gmail.com wrote:
>>>>> Although it may seem contradictory, the patch of
>>>>> the tire has static friction with the road.
>
>> It isn't contradictory to anyone but you.
>
> It’s not contradictory to me. I didn’t say the line above..

oh boy, this is choice!

from the Google archive:
*****************************
On April 17, 2022 at 5:41:48 AM UTC-7, bodk...@gmail.com wrote:
>>> Although it may seem contradictory, the patch of
>>> the tire has static friction with the road. This is because the patch
>>> is stationary relative to the road.
>
> Yes.
******************************

So you didn't SAY it, you merely CONCURRED -

Job interviewer: "Mr. Bodkin, do you consider yourself an honest person?"
Bod: "Yes, certainly I do."
> Well, it’s going to be tricky for you to have any coherent thoughts on more
> advanced physics if you don’t get the 11th grade physics right.
> Remember when you thought runners landed their front foot on the road with
> the foot having horizontal motion, so that the toes would slide forward in
> the shoe’s toe box and jam the front of the toes, and there would be
> skidding wear on the bottom of shoes, and knee and ankle joints would get
> worn from running?

The Lord of the Scatterbrains speaks, hallelujah!

Yes, Lord, I DO remember that! And I remember YOUR claim that,
in Bodworld, the foot moves BACKWARD, relative to the knee, as
the knee flexes... therefore, it ALSO moves backward, relative to the road.
Simple relative motion, 11th grade physics, it's BASIC!

Because, in Bodworld, runners don't suffer stress injuries. Last week,
I did a telephone survey of Bodworld orthopedists, from my Bodworld
phone book. I asked: who's your typical patient? They answered, it's
mostly cyclists and swimmers, which is very stressful, but seldom
runners, which isn't injurious, since their feet move backward.

That's right, because in Bodworld, a runner's lands FLAT FOOTED,
and his sole skids. They don't roll the foot heel-toe, that's unnatural,
human ambulation doesn't work that way.

And, that was the same conversation where you explained how
ballerinas bounce like tennis balls, using gravitational potential
energy conversion, 11th grade physics, it's BASIC!

And, such bouncing explains why runners don't lose energy, they
race on par with roller skaters... um well, maybe not... the skaters
have an advantage due to the WHEEL CIRCUMFERENCE.
"That's the key." -- Bod

Well, that covers it, except for one question: do you know anything about anything?

--
Rich

RichD <r_delaney2001@yahoo.com> wrote:
> On April 18, bodk...@gmail.com wrote:
>>>>>> Although it may seem contradictory, the patch of
>>>>>> the tire has static friction with the road.
>>
>>> It isn't contradictory to anyone but you.
>>
>> It’s not contradictory to me. I didn’t say the line above.
>
> oh boy, this is choice!
>
> from the Google archive:
> *****************************
> On April 17, 2022 at 5:41:48 AM UTC-7, bodk...@gmail.com wrote:
>>>> Although it may seem contradictory, the patch of
>>>> the tire has static friction with the road. This is because the patch
>>>> is stationary relative to the road.
>>
>> Yes.
> ******************************
>
> So you didn't SAY it, you merely CONCURRED -
>
> Job interviewer: "Mr. Bodkin, do you consider yourself an honest person?"
> Bod: "Yes, certainly I do."
>
>> Well, it’s going to be tricky for you to have any coherent thoughts on more
>> advanced physics if you don’t get the 11th grade physics right.
>> Remember when you thought runners landed their front foot on the road with
>> the foot having horizontal motion, so that the toes would slide forward in
>> the shoe’s toe box and jam the front of the toes, and there would be
>> skidding wear on the bottom of shoes, and knee and ankle joints would get
>> worn from running?
>
> The Lord of the Scatterbrains speaks, hallelujah!
>
> Yes, Lord, I DO remember that! And I remember YOUR claim that,
> in Bodworld, the foot moves BACKWARD, relative to the knee, as
> the knee flexes... therefore, it ALSO moves backward, relative to the road.

No, that’s an idiotic statement. The knee is moving forward relative to the
road. The foot is moving backward relative to the knee. And in fact, any
slo-mo video of a runner’s motion will show you that the motion of the foot
in the last vertical inch is downward, not forward or backward. As it needs
to be, so that there is no skidding between the sole of the shoe and the
road, so that the foot does not slide forward inside the shoe’s toe box,
and so that there is no lateral but only compressive strain in the ankle.

> Simple relative motion, 11th grade physics, it's BASIC!
>
> Because, in Bodworld, runners don't suffer stress injuries.

They certainly will if the runners run the way you imagine.

> Last week,
> I did a telephone survey of Bodworld orthopedists, from my Bodworld
> phone book. I asked: who's your typical patient? They answered, it's
> mostly cyclists and swimmers, which is very stressful, but seldom
> runners, which isn't injurious, since their feet move backward.
>
> That's right, because in Bodworld, a runner's lands FLAT FOOTED,
> and his sole skids. They don't roll the foot heel-toe, that's unnatural,
> human ambulation doesn't work that way.
>
> And, that was the same conversation where you explained how
> ballerinas bounce like tennis balls, using gravitational potential
> energy conversion, 11th grade physics, it's BASIC!
>
> And, such bouncing explains why runners don't lose energy, they
> race on par with roller skaters... um well, maybe not... the skaters
> have an advantage due to the WHEEL CIRCUMFERENCE.
> "That's the key." -- Bod
>
> Well, that covers it, except for one question: do you know anything about anything?
>
> --
> Rich
>
>

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

RichD wrote:

> On April 15, Thomas 'PointedEars' Lahn wrote:
>>> Consider a rolling wheel, with rubber tire. It's non-ideal,
>>> the rubber flattens at the bottom, maybe an inch.
>>> The tire, over the contact interval, works as planned:
>>> it doesn't slide, relative to the road. Which means it's
>> > at rest, relative to the road.
>>
>> No, it is not. Instead, it would remain at rest relative to the road if
>> it slid completely and would not “flatten at the bottom”.
>
> Say what???

what???

> If the tire slides along the road, it's MOVING relative to the road!

Yes.

> (and then friction defeats the whole purpose)

No.

> The rubber flattens, maybe 3 inches. Call this the track.

This is not called ”the track”.

> The points along the track DON'T slide,

Ex falso quodlibet.

> each point remains
> in contact with a corresponding point on the pavement,

Each is in contact with the road at a *different* point in time. Which
means that each point on the rubber of the tire is motion relative to
the road, AISB.

> that's what "no relative motion" means.

No, it does not.

> Eventually, a point on the track moves to the rear, and lifts.

IOW, the point is in motion relative to the road.

> After that, it moves relative to the road (obviously).

It always moves relative to the road as long as the wheel, and the tire on
it with it, is turning. Do I need to draw it for you?

>> The problem with your argument is a semantic fallacy (perhaps out of
>> ignorance): You are confusing “at rest relative to the road” with “in
>> contact with the road”.
>
> I never commit semantic fallacies.

You have done it before and you are doing it here again.

> I do not confuse these ideas.

But you do.

> The track is in continuous contact with the road.

“Track” means something else than you think. But even if we wuold adopt
your (wrong) definition for ”track”, it is NOT in continuous contact with
the road: at one instant one part is in contact with the road, and the next
instant it is a *different* part of it (unless the tire is perfectly
sliding).

> And each point of the rubber along the track,

You are even confused about your own wrong definitions now. According to
your wrong definition above, the “track” *is* the rubber; so there is no
“rubber along the track”.

> contacts a corresponding fixed point on the road.

No, it does not. The contact point on the road is a different one in each
instant.

> They are relatively at rest, by definition. Do you deny this?

Most certainly I deny this unscientific nonsense of yours.

> Hence, no relative motion,

Ex falso quodlibet.

> how does the bike proceed? That's the challenge for the student.

Dunning–Kruger. You are deluding yourself, thinking that you have already
achieved the understanding to be able to post sensible challenge questions.
First *you* have a lot of studying to do.

>> To keep it simple, we would make use of the rotational symmetry of the
>> situation and define the position of the wheel relative to the road by
>> the horizontal position of its center of rotation. Certainly you can see
>> that then the position of the wheel, if it is rolling on the road,
>> changes relative to the road insofar as that it changes relative to a
>> fixed point on the road.
>
> um yes, the bicycle achieves forward motion. I don't think
> there's any dispute about that.

So does a car. There is no conceptual difference.

> If you want to define "position of the wheel" (or position of the bike)
> as the axle's position relative to the road, that's sensible.

I am glad that you can see that. Now you only have to apply this to the
car’s wheel and tire, and see that your argument does not make sense.

>> And even if you do not agree with that choice, certainly you can see that
>> a fixed point on the rubber of the wheel is in a continuous, oscillating
>> motion relative to (any point on) the road.
>
> Not when we focus on those points along the track!

Different points at each different instant of time.

> You miss the point of the paradox completely.

There is no paradox but the one that arises from your flawed logic.

>>> But it's a wheel, hence achieves continuous forward motion.
>>
>> Because there is friction between it and the road and (ideally) it does
>> NOT slide at all.
>
> Right. Which contradicts your statements above.

No, it does not. You are not thinking clearly.

PointedEars
--
Q: How many theoretical physicists specializing in general relativity
does it take to change a light bulb?
A: Two: one to hold the bulb and one to rotate the universe.
(from: WolframAlpha)

On April 19, Thomas 'PointedEars' Lahn wrote:
>>> Consider a rolling wheel, with rubber tire. It's non-ideal,
>>> the rubber flattens at the bottom, maybe an inch.
>>> The tire, over the contact interval, works as planned:
>>> it doesn't slide, relative to the road. Which means it's
>>> at rest, relative to the road.
>
> No, it is not. Instead, it would remain at rest relative to the road if
> it slid completely and would not “flatten at the bottom”.

oh
So, a bicycle tire doesn't flatten.

And, if it slid, it would remain at rest relative to the road.

>> If the tire slides along the road, it's MOVING relative to the road!
> Yes.

And, if the tire slid, it would move relative to the road.

[the rest of your schizophrenia snipped]

PS Does the fly, sitting on the tire track at the bottom,
rolling along the road, see the house move?

--
Rich

On April 19, bodk...@gmail.com wrote:
>> And I remember YOUR claim that, in Bodworld, the foot
>>moves BACKWARD, relative to the knee, as
>> the knee flexes... therefore, it ALSO moves backward, relative to the road.
>
> No, that’s an idiotic statement. The knee is moving forward relative to the
> road. The foot is moving backward relative to the knee. And in fact, any
> slo-mo video of a runner’s motion will show you that the motion of the foot
> in the last vertical inch is downward, not forward or backward. As it needs
> to be, so that there is no skidding between the sole of the shoe and the
> road, so that the foot does not slide forward inside the shoe’s toe box,
> and so that there is no lateral but only compressive strain in the ankle.
>
>> Simple relative motion, 11th grade physics, it's BASIC!
>> Because, in Bodworld, runners don't suffer stress injuries.
>
> They certainly will if the runners run the way you imagine.

So, in Bodworld, runners don't suffer stress fractures and
ligament injuries.
Orthopedists don't pay their kids' college tuition by treating runners.
Runners don't roll the foot heel-toe.
As the foot falls onto the road, it cannot also be moving forward,
relative to the road, we learned that in 11th grade physics.

The roller skater's shoe continues rolling after it lands...
the runner's shoe also continues rolling, or levitating, or something...
so the runner suffers no loss of forward motion, no loss of
kinetic energy, no excess fatigue... because the foot doesn't
STOP DEAD when it lands.

A dozed repetitions of this of course grows wearisome. But
I confess a warped amusement in watching your desperate
flailing, as you attempt to defend your imbecilities and denials.

This isn't about content, which was settled long ago, but all
about your character defects.

--
Rich

RichD <r_delaney2001@yahoo.com> wrote:
> On April 19, bodk...@gmail.com wrote:
>>> And I remember YOUR claim that, in Bodworld, the foot
>>> moves BACKWARD, relative to the knee, as
>>> the knee flexes... therefore, it ALSO moves backward, relative to the road.
>>
>> No, that’s an idiotic statement. The knee is moving forward relative to the
>> road. The foot is moving backward relative to the knee. And in fact, any
>> slo-mo video of a runner’s motion will show you that the motion of the foot
>> in the last vertical inch is downward, not forward or backward. As it needs
>> to be, so that there is no skidding between the sole of the shoe and the
>> road, so that the foot does not slide forward inside the shoe’s toe box,
>> and so that there is no lateral but only compressive strain in the ankle.
>>
>>> Simple relative motion, 11th grade physics, it's BASIC!
>>> Because, in Bodworld, runners don't suffer stress injuries.
>>
>> They certainly will if the runners run the way you imagine.
>
> So, in Bodworld, runners don't suffer stress fractures and
> ligament injuries.

They would certainly suffer them much more frequently and severely if they
ran the way you describe.

Rich, rather than just yapping about your reasons for *thinking so*, just
LOOK at a video of the kinematics of a runner. They’re all over the place.
Here’s one: https://youtu.be/XV2vIEVCwzE. If you don’t like that one, find
others yourself. Note that when the runner’s foot lands on the pavement, it
is not moving horizontally with respect to the road and it IS moving
horizontally backwards relative to the knee. Run the video in slow motion
if you like. Then after you’ve LOOKED, tell me that runners don’t actually
move that way and they instead move the way you describe.

> Orthopedists don't pay their kids' college tuition by treating runners.
> Runners don't roll the foot heel-toe.
> As the foot falls onto the road, it cannot also be moving forward,
> relative to the road, we learned that in 11th grade physics.
>
> The roller skater's shoe continues rolling after it lands...
> the runner's shoe also continues rolling, or levitating, or something...
> so the runner suffers no loss of forward motion, no loss of
> kinetic energy, no excess fatigue... because the foot doesn't
> STOP DEAD when it lands.
>
> A dozed repetitions of this of course grows wearisome. But
> I confess a warped amusement in watching your desperate
> flailing, as you attempt to defend your imbecilities and denials.
>
> This isn't about content, which was settled long ago, but all
> about your character defects.
>
> --
> Rich
>

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

RichD wrote:

> On April 19, Thomas 'PointedEars' Lahn wrote:
>>>> Consider a rolling wheel, with rubber tire. It's non-ideal,
>>>> the rubber flattens at the bottom, maybe an inch.
>>>> The tire, over the contact interval, works as planned:
>>>> it doesn't slide, relative to the road. Which means it's
>>>> at rest, relative to the road.
>>
>> No, it is not. Instead, it would remain at rest relative to the road if
>> it slid completely and would not “flatten at the bottom”.
>
> oh
> So, a bicycle tire doesn't flatten.

It does. I never claimed otherwise. You need to learn *comprehensive*
reading.
> And, if it slid, it would remain at rest relative to the road.

It would not, as anyone who had the misfortune to slid on an overfrozen road
with their bike (including me) would tell you.

Again, for the mentally challenged: Sliding is a form of MOTION, NOT rest.

You are still not thinking clearly.
>>> If the tire slides along the road, it's MOVING relative to the road!
>> Yes.
>
> And, if the tire slid, it would move relative to the road.

Yes. And this sentence contradicts your sentence further above.

You are still not thinking clearly.
> [the rest of your schizophrenia snipped]

Pot, kettle, black.
> PS Does the fly, sitting on the tire track at the bottom,
> rolling along the road, see the house move?

Yes, of course, until it is squashed after one rotation.

Both because the tire is moving, and is NOT at rest, relative to the road.
That is what “rolling” MEANS.

*facepalm*

PointedEars
--
Q: How many theoretical physicists specializing in general relativity
does it take to change a light bulb?
A: Two: one to hold the bulb and one to rotate the universe.
(from: WolframAlpha)

Thomas 'PointedEars' Lahn wrote:

> RichD wrote:
>> Consider a rolling wheel, with rubber tire. It's non-ideal,
>> the rubber flattens at the bottom, maybe an inch.
>>
>> The tire, over the contact interval, works as planned:
>> it doesn't slide, relative to the road. Which means it's
>> at rest, relative to the road.
>
> No, it is not. Instead, it would remain at rest relative to the road if
> it slid completely and would not “flatten at the bottom”.

I can see that this wording, in which I attempted to interpret and adopt
"RichD’s" (wrong) definition of “at rest relative to …” was confusing. Just
assume that I did not write that, and assume that I meant the same as I
wrote and meant subsequently:

Neither a wheel that is rolling nor a wheel that is sliding is ever at rest
relative to the road, because both are kinds of motion.

What remains constant in both cases (ideally) is only the distance that the
wheel has to the road (e.g. the distance of its center to a point on the
road obtained from a line perpendicular to the road through the center of
the wheel). But that is NOT how we define “at rest relative to a road”
*along* which the wheel must move.

PointedEars
--
A neutron walks into a bar and inquires how much a drink costs.
The bartender replies, "For you? No charge."

(from: WolframAlpha)

On April 20, bodk...@gmail.com wrote:
>>> The knee is moving forward relative to the
>>> road. The foot is moving backward relative to the knee. And in fact, any
>>> slo-mo video of a runner’s motion will show you that the motion of the foot
>>> in the last vertical inch is downward, not forward or backward.
>
>> So, in Bodworld, runners don't suffer stress fractures and
>> ligament injuries.
>
> They would certainly suffer them much more frequently and severely if they
> ran the way you describe.
> Rich, rather than just yapping about your reasons for *thinking so*, just
> LOOK at a video of the kinematics of a runner.
> https://youtu.be/XV2vIEVCwzE.

Very good video.

> Note that when the runner’s foot lands on the pavement, it
> is not moving horizontally with respect to the road and it IS moving
> horizontally backwards relative to the knee.
> Then after you’ve LOOKED, tell me that runners don’t actually
> move that way and they instead move the way you describe.

You hallucinate.

The shin is oriented vertically, but doesn't fall 'vertical',
that's an illusion. The shin is moving FORWARD, relative
to the road, at impact. As minimal sense tells us.

Your eye-brain coordination is underdeveloped, and your
ludicrous notion that a runner's feet don't move forward,
remains ludicrous.

However, it's interesting that an elite runner lands flat,
unlike the recreational runner. Obviously it offers superior
performance.

But his foot immediately rolls onto the toes, in continuous
motion. He doesn't land like a stone statue, that's strictly
Bodworld. Hence your imagined sliding and injuries remain
your imagination.

Now, since eleventh grade physics stumps you, let's dumb
it down to sixth grade level: why does a fat man run slower
than a thin man?

The answer also explains why a bicyclist is faster than a runner.
It isn't the gear train -

--
Rich

On April 21, Thomas 'PointedEars' Lahn wrote:
>>> The tire, over the contact interval, works as planned:
>>> it doesn't slide, relative to the road. Which means it's
>>> at rest, relative to the road.
>
>> No, it is not. Instead, it would remain at rest relative to the road if
>> it slid completely and would not “flatten at the bottom”..
>
> I can see that this wording, in which I attempted to interpret and adopt
> "RichD’s" (wrong) definition of “at rest relative to …” was confusing. Just
> assume that I did not write that, and assume that I meant the same as I
> wrote and meant subsequently:
> Neither a wheel that is rolling nor a wheel that is sliding is ever at rest
> relative to the road, because both are kinds of motion.

You attempt to correct yourself.
Full credit.

But you still miss the point.
All you have done is assert that a bicycle travels forward. duh

We have:
i) The bicycle travels along the road.
ii) It accomplishes this because it's in contact with the road.
(a bike in midair doesn't go far)
iii) The part in contact with the road - the flat track - doesn't
slide; i.e. NO MOTION RELATIVE TO THE ROAD

Thus we see a contradiction. That defines a paradox.
The challenge is to resolve it.

You haven't addressed the question, you DON'T EVEN
UNDERSTAND THE QUESTION! Such confusion is gratifying
to the one who presents the paradox.

To make it clearer, visualize a tank track, instead of
a bicycle. It's 8 feet long, flat along the road.
[insert animation here]
Visualize a point P on the track, at the front vertex,
as it contacts the road, at point Q on the road.

Now, your second chance, a quiz for the student:
as P moves along the track to the rear vertex - it rolls -
does it ever SEPARATE from Q?
Does the fly, riding on P, see the house move?

Think hard, very hard, this time -

--
Rich

RichD <r_delaney2001@yahoo.com> wrote:
> On April 20, bodk...@gmail.com wrote:
>>>> The knee is moving forward relative to the
>>>> road. The foot is moving backward relative to the knee. And in fact, any
>>>> slo-mo video of a runner’s motion will show you that the motion of the foot
>>>> in the last vertical inch is downward, not forward or backward.
>>
>>> So, in Bodworld, runners don't suffer stress fractures and
>>> ligament injuries.
>>
>> They would certainly suffer them much more frequently and severely if they
>> ran the way you describe.
>> Rich, rather than just yapping about your reasons for *thinking so*, just
>> LOOK at a video of the kinematics of a runner.
>> https://youtu.be/XV2vIEVCwzE.
>
> Very good video.
>
>> Note that when the runner’s foot lands on the pavement, it
>> is not moving horizontally with respect to the road and it IS moving
>> horizontally backwards relative to the knee.
>> Then after you’ve LOOKED, tell me that runners don’t actually
>> move that way and they instead move the way you describe.
>
> You hallucinate.
>
> The shin is oriented vertically, but doesn't fall 'vertical',
> that's an illusion. The shin is moving FORWARD, relative
> to the road, at impact. As minimal sense tells us.

You can’t read. I said FOOT, not shin. The shin is changing angle.

>
> Your eye-brain coordination is underdeveloped, and your
> ludicrous notion that a runner's feet don't move forward,
> remains ludicrous.
>
> However, it's interesting that an elite runner lands flat,
> unlike the recreational runner. Obviously it offers superior
> performance.
>
> But his foot immediately rolls onto the toes, in continuous
> motion. He doesn't land like a stone statue,

I never said he did. I never said the foot remains rigid.
But the shoe does not have to be slid to a stop by the road, and the foot
inside the shoe does not have to be slid to a stop by the insole.

> that's strictly
> Bodworld. Hence your imagined sliding and injuries remain
> your imagination.
>
> Now, since eleventh grade physics stumps you, let's dumb
> it down to sixth grade level: why does a fat man run slower
> than a thin man?
>
> The answer also explains why a bicyclist is faster than a runner.
> It isn't the gear train -
>
> --
> Rich
>

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

RichD <r_delaney2001@yahoo.com> wrote:
> On April 21, Thomas 'PointedEars' Lahn wrote:
>>>> The tire, over the contact interval, works as planned:
>>>> it doesn't slide, relative to the road. Which means it's
>>>> at rest, relative to the road.
>>
>>> No, it is not. Instead, it would remain at rest relative to the road if
>>> it slid completely and would not “flatten at the bottom”.
>>
>> I can see that this wording, in which I attempted to interpret and adopt
>> "RichD’s" (wrong) definition of “at rest relative to …” was confusing. Just
>> assume that I did not write that, and assume that I meant the same as I
>> wrote and meant subsequently:
>> Neither a wheel that is rolling nor a wheel that is sliding is ever at rest
>> relative to the road, because both are kinds of motion.
>
> You attempt to correct yourself.
> Full credit.
>
> But you still miss the point.
> All you have done is assert that a bicycle travels forward. duh
>
> We have:
> i) The bicycle travels along the road.
> ii) It accomplishes this because it's in contact with the road.
> (a bike in midair doesn't go far)
> iii) The part in contact with the road - the flat track - doesn't
> slide; i.e. NO MOTION RELATIVE TO THE ROAD
>
> Thus we see a contradiction. That defines a paradox.

There’s no contradiction.

The CENTER of the wheel travels relative to the road. The BOTTOM of the
wheel does not travel relative to the road. The TOP of the wheel travels
even faster than the center of the wheel, relative to the road.

What about this gives you trouble?

> The challenge is to resolve it.
>
> You haven't addressed the question, you DON'T EVEN
> UNDERSTAND THE QUESTION! Such confusion is gratifying
> to the one who presents the paradox.
>
> To make it clearer, visualize a tank track, instead of
> a bicycle. It's 8 feet long, flat along the road.
> [insert animation here]
> Visualize a point P on the track, at the front vertex,
> as it contacts the road, at point Q on the road.
>
> Now, your second chance, a quiz for the student:
> as P moves along the track to the rear vertex - it rolls -
> does it ever SEPARATE from Q?
> Does the fly, riding on P, see the house move?
>
> Think hard, very hard, this time -
>
> --
> Rich
>

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

RichD wrote:

> On April 21, Thomas 'PointedEars' Lahn wrote:
>>>> The tire, over the contact interval, works as planned:
>>>> it doesn't slide, relative to the road. Which means it's
>>>> at rest, relative to the road.
>>> No, it is not. Instead, it would remain at rest relative to the road if
>>> it slid completely and would not “flatten at the bottom”.
>>
>> I can see that this wording, in which I attempted to interpret and adopt
>> "RichD’s" (wrong) definition of “at rest relative to …” was confusing.
>> Just assume that I did not write that, and assume that I meant the same
>> as I wrote and meant subsequently:
>> Neither a wheel that is rolling nor a wheel that is sliding is ever at
>> rest relative to the road, because both are kinds of motion.
>
> You attempt to correct yourself.

No, instead I am clarifying what I meant.

> But you still miss the point.

No.

> All you have done is assert that a bicycle travels forward. duh
>
> We have:
> i) The bicycle travels along the road.

Yes.

> ii) It accomplishes this because it's in contact with the road.
> (a bike in midair doesn't go far)

True.

I also want to emphasize that there is an ambiguity in the definition of
“sliding” that can have caused a misunderstanding:

When I wrote “slide”, I meant: the wheel can, but does not have to, rotate
for the vehicle to move (forward).

Another definition of a ”sliding wheel” is that the vehicle does NOT move
because the coefficient of friction with the road is low enough (or the
wheel is not in contact with the road at all) so that the wheel rotates
without giving traction to the vehicle. That is NOT what I meant, but it
might be what you meant.

> iii) The part in contact with the road - the flat track - doesn't
> slide;

Ideally, yes.

> i.e. NO MOTION RELATIVE TO THE ROAD

That is where you are wrong, perhaps based on a wrong definition of relative
motion.

Consider that, put simply, the point on the road opposite the center of the
wheel is a different one in each instant: If you put a marker on the road,
and let the vehicle roll, then its distance to that marker will increase.

*That* is what we mean by “motion relative to the road”: the road it its
entirety, with the potential kilometre markers or milestones placed along
it, are our frame of reference. Using them, we define and determine the
speed of the vehicle on the road.

IOW, the speed of the vehicle on the road is NOT defined as how fast the
vertical distance between wheel and road changes.

> Thus we see a contradiction.

This contradiction only arises because of your wrong definition of “motion
relative to the road”, and the conclusion drawn from that.

> That defines a paradox.

This paradox only seemingly arises, due of your wrong definition and,
following that, flawed logic.

> The challenge is to resolve it.

There is no paradox, so none to resolve.

You need to formulate a *true* premise; then the contradiction from the
conclusion from the false premise will vanish in a puff of logic.

Ex falso sequitur quodlibet.

PointedEars
--
I heard that entropy isn't what it used to be.

(from: WolframAlpha)

Odd Bodkin wrote:

> RichD <r_delaney2001@yahoo.com> wrote:
>> On April 21, Thomas 'PointedEars' Lahn wrote:
>>>>> The tire, over the contact interval, works as planned:
>>>>> it doesn't slide, relative to the road. Which means it's
>>>>> at rest, relative to the road.
>>>
>>>> No, it is not. Instead, it would remain at rest relative to the road if
>>>> it slid completely and would not “flatten at the bottom”.
>>>
>>> I can see that this wording, in which I attempted to interpret and adopt
>>> "RichD’s" (wrong) definition of “at rest relative to …” was confusing.
>>> Just assume that I did not write that, and assume that I meant the same
>>> as I wrote and meant subsequently:
>>> Neither a wheel that is rolling nor a wheel that is sliding is ever at
>>> rest relative to the road, because both are kinds of motion.
>>
>> You attempt to correct yourself.
>> Full credit.
>>
>> But you still miss the point.
>> All you have done is assert that a bicycle travels forward. duh
>>
>> We have:
>> i) The bicycle travels along the road.
>> ii) It accomplishes this because it's in contact with the road.
>> (a bike in midair doesn't go far)
>> iii) The part in contact with the road - the flat track - doesn't
>> slide; i.e. NO MOTION RELATIVE TO THE ROAD
>>
>> Thus we see a contradiction. That defines a paradox.
>
> There’s no contradiction.
>
> The CENTER of the wheel travels relative to the road.

Yes.

> The BOTTOM of the wheel does not travel relative to the road.

I do not think it is helpful to introduce ill-defined concepts like ”bottom
of the wheel”. It only leads to misconceptions such as the following:

> The TOP of the wheel travels even faster than the center of the wheel,
> relative to the road.

If the “bottom” does not travel relative to the road, then neither does
the “top”. If what you say were possible, if you were using a consistent
conceptual framework, then the wheel would have to disintegrate as it is
rotating.

Your latter statement only makes sense in a different conceptual framework,
namely when we consider a point on the wheel that is orbiting the center of
the wheel as the wheel is turning. For example, a marker on the tire. And
then, of course, there is no difference between the speed of a marker on the
bottom of the tire and one on the top, as the marker on the bottom will
cyclically become one on the top and vice-versa.

PointedEars
--
Q: Where are offenders sentenced for light crimes?
A: To a prism.

(from: WolframAlpha)

Thomas 'PointedEars' Lahn wrote:

> I can see that this wording, in which I attempted to interpret and adopt
> "RichD’s" (wrong) definition of “at rest relative to …” was confusing.
> Just assume that I did not write that, and assume that I meant the same
> as I wrote and meant subsequently:

here's your nazis you are starving for. Beating children, disgusting sons
of the bitches. Strange your govt is not allying with Russia removing
these nazis wherever they are. There are shitholes countries, *knowingly*
arming the nazis with hard weaponry. The new *_bio_weapon_labs_* nazis.

Proof of Ukrainian Neo-Nazi Satanism and Underground Biolabs. Is Putin at
War With The NWO https://www.bitchute.com/video/Wj54U4w9JbeP/

The ’nym-shifting troll trolled as ”Sam Kaloxylos”:

> [fake news about Ukraine

You should watch less Russian propaganda. It has obviously
fried what little was left of your working brain cells.

PointedEars
--
Q: What happens when electrons lose their energy?
A: They get Bohr'ed.

(from: WolframAlpha)

Thomas 'PointedEars' Lahn wrote:

> The ’nym-shifting troll trolled as ”Sam Kaloxylos”:
>
>> [fake news about Ukraine
>
> You should watch less Russian propaganda. It has obviously fried what
> little was left of your working brain cells.

That's not me, but all those are americans and canadians. And you are the
idiot they are talking about. A braindead cretin arming the nazis in the
fictitious "ukraine". Learn engilsh, idiot.

Proof of Ukrainian Neo-Nazi Satanism and Underground Biolabs. Is Putin at
War With The NWO https://www.bitchute.com/video/Wj54U4w9JbeP/

Sam Kaloxylos <neeo@kzynutyj.ye> wrote in sci.physics.relativity:

> Thomas 'PointedEars' Lahn wrote:
>
> > The 'nym-shifting troll trolled as "Sam Kaloxylos":
> >
> >> [fake news about Ukraine
> >
> > You should watch less Russian propaganda. It has obviously fried what
> > little was left of your working brain cells.
>
> Is general Michael Flynn "russian", pointedhead?? What an idiot.
>
> Proof of Ukrainian Neo-Nazi Satanism and Underground Biolabs. Is Putin at
> War With The NWO https://www.bitchute.com/video/Wj54U4w9JbeP/
>

Apparently Thomas 'PointedEars' Lahn has confused alt.1d
with alt.dev.null when setting a sneaky silent followup in his
Message-ID: <1907248.PYKUYFuaPT@PointedEars.de> which
was posted in sci.physics.relativity.

I suppose he thinks he's clever, whereas in fact he is simply
displaying his pettiness. Shame on you, you pointy-eared
person.

[Crosspost and Followup-To: alt.dev.null]

Learn from this example Thomas, lest you appear to be a newbie,
ignorant of netiquette. Kindly cease littering alt.1d with your
puerile pranks.

Thank you for your kind attention; we now return you to your
regular programming.
--
^Ï^ Slava Ukraini

My pet rock Gordon just is.

On 14-Apr-22 6:20 am, RichD wrote:
> Consider a rolling wheel, with rubber tire. It's non-ideal,
> the rubber flattens at the bottom, maybe an inch.
>
> The tire, over the contact interval, works as planned:
> it doesn't slide, relative to the road. Which means it's
> at rest, relative to the road.
>
> Therefore, the tire/wheel cannot achieve forward motion.
> But it's a wheel, hence achieves continuous forward motion.
> Therefore, first order logic is shown inconsistent.
> Therefore, 1 = 2
> QED
>
> Therefore, arithmetic crumbles, and with it all science,
> which depends on that. The laws of nature are thus
> invalidated, and the universe implodes.
>
> It was a nice ride, for 13 billion years, but the party's over -
>
> --
> Rich

You've already posited that the tyre is not rigid, but to some extent
elastic. So the axle can move by compressing parts of the tyre and
stretching others.

As aside, not all the energy put into the compression and stretching is
recovered. Some ends up as heat. Welcome to rolling resistance.

Sylvia.

RichD <r_delaney2001@yahoo.com> wrote:
> Consider a rolling wheel, with rubber tire. It's non-ideal,
> the rubber flattens at the bottom, maybe an inch.
>
> The tire, over the contact interval, works as planned:
> it doesn't slide, relative to the road. Which means it's
> at rest, relative to the road.
>
> Therefore, the tire/wheel cannot achieve forward motion.
> But it's a wheel, hence achieves continuous forward motion.
> Therefore, first order logic is shown inconsistent.
> Therefore, 1 = 2
> QED
>
> Therefore, arithmetic crumbles, and with it all science,
> which depends on that. The laws of nature are thus
> invalidated, and the universe implodes.
>
> It was a nice ride, for 13 billion years, but the party's over -
>
> --
> Rich
>

Tut tut

https://i.stack.imgur.com/EhSDb.png

For extra credit, take no more than 4 seconds to identify the size of the
velocity vectors at 3:00 and 9:00 in that figure, and the angles they make.

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