Michael Moroney wrote:

>> I'm trying to discuss reality, and all you can understand is
>> mathematics.
>
> Nope. It's just that most science models are heavy in math. Like the
> home run baseball. You (or an outfielder) may almost instinctively
> think of where it will land, but science models have formulas which
> predict

My friend, these 3rd_world ugly things, barely can even fly. Ohh my. What
year is it, 2022??

U.S. Air Force F-35's Support nazi NATO's Collective Defense
https://www.bitchute.com/video/YP7PgwSPOKPa/

On April 3, bodk...@gmail.com wrote:
>> A bicyclist will dust a runner on foot, whether a peak speed
>> sprint, or long distance. Explain this, at the Physics 101 level.
>> Why is a bike faster than Nike?
>
> Well this is fun. I don’t know the answer for sure.
> But beyond that, I think it is due to an inherent limitation of the speed
> of the lower leg’s fast-twitch fibered muscles, coupled with the attachment
> point of the muscle to the lower leg bones. This is also related to why an
> 80 lb chimpanzee is four times stronger than a 180 lb man, but cannot throw
> a ball with any speed; the attachment point of the chimp’s muscle is
> further away from the joint, trading speed for leverage.
>
> Between the cyclist and the sprinter, when both are ramped up to fastest
> leg speed, the bicyclist now has an obvious advantage, because of the ratio
> of the radius of the wheel compared to the radius of the pedal crank, which
> in turn is about the same as the average radius of the runner’s foot
> motion. The tangential speed of the wheel is larger than the tangential
> speed of the foot by the same ratio as that of the radii.

All right, you took up the cudgels, made an effort,
and some reasonable points. Credit where due.
But you still don't get a passing grade. Maybe a D+.

The fast twitch fiber limits is relevant, for the runner. After
the foot pushes off the ground, there's a limit to how much
force can be applied to the femur, how fast it can accelerate
forward. That's a lab measurement question, but not the big
thing; if he accelerates faster, he has to burn more muscle
energy, which IS the big thing.

There's also the question of leverage and anatomy/geometry.
There's always a trade-off between torque and displacement;
a lever isn't a power source.

As the cyclist goes to higher gear ratio, he goes faster, and
faces higher air resistance loss. His muscles have to work
harder to overcome that. Is his metabolism superior to the runner?

The biker gets more bang for his Watt than the runner, we
know that, he's more efficient, by definition; the problem is
to explain that, that's the whole point. Which you haven't.
Nor has anyone else - I've quizzed a couple dozen people,
everyone misses the crucial idea. (usually they babble incessantly
about efficiency)

So, if you haven't dozed off, some hints: analyze it from an energy
viewpoint. Both players suffer energy losses. But the biker
has lower loss, or - more critically - the runner has larger loss.
Put a finger on those losses. Where does the runner lose
the game?

--
Rich

RichD <r_delaney2001@yahoo.com> wrote:
> On April 3, bodk...@gmail.com wrote:
>>> A bicyclist will dust a runner on foot, whether a peak speed
>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>> Why is a bike faster than Nike?
>>
>> Well this is fun. I don’t know the answer for sure.
>> But beyond that, I think it is due to an inherent limitation of the speed
>> of the lower leg’s fast-twitch fibered muscles, coupled with the attachment
>> point of the muscle to the lower leg bones. This is also related to why an
>> 80 lb chimpanzee is four times stronger than a 180 lb man, but cannot throw
>> a ball with any speed; the attachment point of the chimp’s muscle is
>> further away from the joint, trading speed for leverage.
>>
>> Between the cyclist and the sprinter, when both are ramped up to fastest
>> leg speed, the bicyclist now has an obvious advantage, because of the ratio
>> of the radius of the wheel compared to the radius of the pedal crank, which
>> in turn is about the same as the average radius of the runner’s foot
>> motion. The tangential speed of the wheel is larger than the tangential
>> speed of the foot by the same ratio as that of the radii.
>
> All right, you took up the cudgels, made an effort,
> and some reasonable points. Credit where due.
> But you still don't get a passing grade. Maybe a D+.
>
> The fast twitch fiber limits is relevant, for the runner. After
> the foot pushes off the ground, there's a limit to how much
> force can be applied to the femur, how fast it can accelerate
> forward. That's a lab measurement question, but not the big
> thing; if he accelerates faster, he has to burn more muscle
> energy, which IS the big thing.
>
> There's also the question of leverage and anatomy/geometry.
> There's always a trade-off between torque and displacement;
> a lever isn't a power source.
>
> As the cyclist goes to higher gear ratio, he goes faster, and
> faces higher air resistance loss. His muscles have to work
> harder to overcome that. Is his metabolism superior to the runner?
>
> The biker gets more bang for his Watt than the runner, we
> know that, he's more efficient, by definition;

See the radius of the wheel compared to the radius of the runner’s foot
motion. Which I did talk about. That’s the key.

> the problem is
> to explain that, that's the whole point. Which you haven't.
> Nor has anyone else - I've quizzed a couple dozen people,
> everyone misses the crucial idea. (usually they babble incessantly
> about efficiency)
>
> So, if you haven't dozed off, some hints: analyze it from an energy
> viewpoint. Both players suffer energy losses. But the biker
> has lower loss, or - more critically - the runner has larger loss.
> Put a finger on those losses. Where does the runner lose
> the game?
>
> --
> Rich
>
>
>

--
Odd Bodkin — Maker of fine toys, tools, tables

Some thirty years or so ago a bet was made between a runner and a
cyclist about which of them could finish a course first, with the runner
going one lap around a 4.3 mile circular road, and the cyclist doing two
laps. Both were experienced and capable, but not world class.

Along with 20-30 spectators, I witnessed the race. The cyclist won by
several hundred yards.

Tom Roberts

On April 3, bodk...@gmail.com wrote:
>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>> Why is a bike faster than Nike?
>
>>> Between the cyclist and the sprinter, when both are ramped up to fastest
>>> leg speed, the bicyclist now has an obvious advantage, because of the ratio
>>> of the radius of the wheel compared to the radius of the pedal crank, which
>>> in turn is about the same as the average radius of the runner’s foot
>>> motion. The tangential speed of the wheel is larger than the tangential
>>> speed of the foot by the same ratio as that of the radii.
>
>> There's also the question of leverage and anatomy/geometry.
>> There's always a trade-off between torque and displacement;
>> a lever isn't a power source.
>> As the cyclist goes to higher gear ratio, he goes faster, and
>> faces higher air resistance loss. His muscles have to work
>> harder to overcome that. Is his metabolism superior to the runner?
>
> See the radius of the wheel compared to the radius of the runner’s foot
> motion. Which I did talk about. That’s the key.

That's a common try: "the gearing acts like a speed amplifier,
it gives the cyclist an edge." It's fatally flawed. A gear train and
large wheel may be a speed amp, but it isn't a power amp. THAT is the key.

Think about an automobile. At 30 mph, it encounters maybe 5 kW
air resistance; at 60 mph, 20 kW. The engine must burn fuel equal
to those numbers. The gear train has NO EFFECT on this fact.

A combustion engine runs optimally over a limited rpm range.
The gear train is purposed to run the engine within that range,
while enabling a large road speed range. It isn't an energy source!

To hammer the point: a Tesla S has a top end of 200 mph.
It has a single fixed gear ratio. The motor runs up to whatever
revs necessary. Now, if the Tesla designers hew to the Bodkin
theory of mechanics, they insert an extra 2:1 gearbox, and voila, it goes 400 mph!

Same for the bicyclist. He operates with force and rpm constraints
at his 'engine', the hip joint. These are separate from his calorie burn
rate limits. The gearing and wheel size enable greater road speed. But
it isn't free! He must still overcome losses, at whatever speed he travels,
THAT is the ultimate constraint. A bicycle doesn't turn one into Superman.

If you wish to debate physics and mechanical engineering,
you must first learn the basics.

So, the biker and runner are identical twins, same metabolism. At any
given speed, they face the same air resistance. (I don't know how true that is)
To maintain constant speed, each must burn as required to overcome the loss
at that speed. Their burn rate, when they race, is identical.

The bike goes faster because it's more efficient, duh. It suffers lower loss,
the runner suffers greater loss. Where exactly is the runner's handicap?

It's one of those things, obvious once you see it -

--
Rich

On April 3, J. J. Lodder wrote:
>> Show us you know the FIRST THING about the subject -
>
> Alas, you don't,

hey JJ, how does this pendulum work?

https://www.aliexpress.com/i/4000608142508.html

--
Rich

RichD <r_delaney2001@yahoo.com> wrote:

> On April 3, J. J. Lodder wrote:
> >> Show us you know the FIRST THING about the subject -
> >
> > Alas, you don't,

[you snipped all of my text that showed you were wrong]

> hey JJ, how does this pendulum work?
>
> https://www.aliexpress.com/i/4000608142508.html

You failed to notice that power cable?
(it charges the battery in the base)

Jan

RichD <r_delaney2001@yahoo.com> wrote:
> On April 3, bodk...@gmail.com wrote:
>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>> Why is a bike faster than Nike?
>>
>>>> Between the cyclist and the sprinter, when both are ramped up to fastest
>>>> leg speed, the bicyclist now has an obvious advantage, because of the ratio
>>>> of the radius of the wheel compared to the radius of the pedal crank, which
>>>> in turn is about the same as the average radius of the runner’s foot
>>>> motion. The tangential speed of the wheel is larger than the tangential
>>>> speed of the foot by the same ratio as that of the radii.
>>
>>> There's also the question of leverage and anatomy/geometry.
>>> There's always a trade-off between torque and displacement;
>>> a lever isn't a power source.
>>> As the cyclist goes to higher gear ratio, he goes faster, and
>>> faces higher air resistance loss. His muscles have to work
>>> harder to overcome that. Is his metabolism superior to the runner?
>>
>> See the radius of the wheel compared to the radius of the runner’s foot
>> motion. Which I did talk about. That’s the key.
>
> That's a common try: "the gearing acts like a speed amplifier,
> it gives the cyclist an edge." It's fatally flawed. A gear train and
> large wheel may be a speed amp, but it isn't a power amp. THAT is the key.

Which is why a runner will beat the cyclist for the first 20 yards or so.

>
> Think about an automobile. At 30 mph, it encounters maybe 5 kW
> air resistance; at 60 mph, 20 kW. The engine must burn fuel equal
> to those numbers. The gear train has NO EFFECT on this fact.

Here’s a little experiment you can do with a geared bicycle, let’s say 10
speeds.

Get yourself going until you are cruising in 7th gear, with a crank
revolution rate of about 1 Hz, whatever that road speed turns out to be.
Now push harder on the pedals and you’ll be able to accelerate.

But now repeat the experiment until you are going at the same crank rate in
7th gear, and then shift down into 2nd gear, where your crank revolution
rate is likely to be 4 or 5 Hz. Now try to accelerate. Why can’t you?

>
> A combustion engine runs optimally over a limited rpm range.
> The gear train is purposed to run the engine within that range,
> while enabling a large road speed range. It isn't an energy source!
>
> To hammer the point: a Tesla S has a top end of 200 mph.
> It has a single fixed gear ratio. The motor runs up to whatever
> revs necessary. Now, if the Tesla designers hew to the Bodkin
> theory of mechanics, they insert an extra 2:1 gearbox, and voila, it goes 400 mph!
>
> Same for the bicyclist. He operates with force and rpm constraints
> at his 'engine', the hip joint. These are separate from his calorie burn
> rate limits. The gearing and wheel size enable greater road speed. But
> it isn't free! He must still overcome losses, at whatever speed he travels,
> THAT is the ultimate constraint. A bicycle doesn't turn one into Superman.
>
> If you wish to debate physics and mechanical engineering,
> you must first learn the basics.
>
> So, the biker and runner are identical twins, same metabolism. At any
> given speed, they face the same air resistance. (I don't know how true that is)
> To maintain constant speed, each must burn as required to overcome the loss
> at that speed. Their burn rate, when they race, is identical.
>
> The bike goes faster because it's more efficient, duh. It suffers lower loss,
> the runner suffers greater loss. Where exactly is the runner's handicap?
>
> It's one of those things, obvious once you see it -
>

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

Odd Bodkin <bodkinodd@gmail.com> wrote:

> RichD <r_delaney2001@yahoo.com> wrote:
> > On April 3, bodk...@gmail.com wrote:
> >>>>> A bicyclist will dust a runner on foot, whether a peak speed
> >>>>> sprint, or long distance. Explain this, at the Physics 101 level.
> >>>>> Why is a bike faster than Nike?
> >>
> >>>> Between the cyclist and the sprinter, when both are ramped up to
> >>>> fastest leg speed, the bicyclist now has an obvious advantage,
> >>>> because of the ratio of the radius of the wheel compared to the
> >>>> radius of the pedal crank, which in turn is about the same as the
> >>>> average radius of the runner's foot motion. The tangential speed of
> >>>> the wheel is larger than the tangential speed of the foot by the same
> >>>> ratio as that of the radii.
> >>
> >>> There's also the question of leverage and anatomy/geometry.
> >>> There's always a trade-off between torque and displacement;
> >>> a lever isn't a power source.
> >>> As the cyclist goes to higher gear ratio, he goes faster, and
> >>> faces higher air resistance loss. His muscles have to work
> >>> harder to overcome that. Is his metabolism superior to the runner?
> >>
> >> See the radius of the wheel compared to the radius of the runner's foot
> >> motion. Which I did talk about. That's the key.
> >
> > That's a common try: "the gearing acts like a speed amplifier,
> > it gives the cyclist an edge." It's fatally flawed. A gear train and
> > large wheel may be a speed amp, but it isn't a power amp. THAT is the key.
>
> Which is why a runner will beat the cyclist for the first 20 yards or so.

For more yards than that. Look at some video of Usain Bolt taking off.
You'll see that his body is hanging forward at about 45 degrees.
By elementary mecanics that means he is accelerating at about 1 g.
There is no way that a cyclist can accomplish this.
He doesn't have the adhesion weight,
and he cannot bring the force of his legs to bear.
(because his arms cannot take the reaction force)
Cycling is efficient only when already at speed.

Enough said I think, no point in wasting more words
on a subject that RichD is clearly incompetent about,

Jan

On April 4, RichD wrote:
>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>> Why is a bike faster than Nike?
>
> That's a common try: "the gearing acts like a speed amplifier,
> it gives the cyclist an edge." It's fatally flawed. A gear train and
> large wheel may be a speed amp, but it isn't a power amp. THAT is the key.
> So, the biker and runner are identical twins, same metabolism. At any
> given speed, they face the same air resistance.
> To maintain constant speed, each must burn as required to overcome the loss
> at that speed. Their burn rate, when they race, is identical.
> The bike goes faster because it's more efficient, duh. It suffers lower loss,
> the runner suffers greater loss. Where exactly is the runner's handicap?

And the solution is ..... <drum roll> ... every time the runner's front foot
hits the pavement, it STOPS DEAD! It's a colossal kinetic energy waste.
Then as he pushes off, he has to recover that energy. The cyclist suffers
nothing comparable.

To make it clearer, picture two sprinters, side by side, one on
roller skates. What happens when the skater's front foot lands?
It couldn't be clearer.

An interesting question arises - why can no one answer this question?
My guess is, walking and running is so deep in our bones, we're numb
to the stop/start aspect of the activity, it's invisible.

--
Rich

On April 5, J. J. Lodder wrote:
>>>> Show us you know the FIRST THING about the subject -
>
>>> Alas, you don't,
>
> [you snipped all of my text that showed you were wrong]

uhhhhh.....
Let's review this fascinating dialogue.
I asked why a bike is faster than sneakers, whether peak sprint or distance.
You retorted (in character): out of the starting blocks, the sprinter wins a
100 meter race. Therefore I'm WRONG WRONG WRONG!

Yes, I did snip that, out of courtesy, to avoid embarrassing you.
To no avail, given your capacity for that activity.

>> hey JJ, how does this pendulum work?
>> https://www.aliexpress.com/i/4000608142508.html
>
> You failed to notice that power cable?
> (it charges the battery in the base)

oh
Well, that's informative and enlightening. As expected.
Consider me informed and enlightened.

So I went to my garden yesterday, dug a pit, and drove a wood
post into it, then I hung a bob from the top. Voila, a pendulum clock.
Groovy. It ran for two minutes, then pooped out. Bummer.

So then I thought: JJ told me the secret! So I dug another pit underneath,
and tossed a AA battery and power cable inside. Now it runs perpetually!
Thanks JJ, I couldn't do it without you.

PS When you answered thus at your oral defense, did the
committee pat you on the head and award your degree?

--
Rich

RichD <r_delaney2001@yahoo.com> wrote:

> On April 5, J. J. Lodder wrote:
> >>>> Show us you know the FIRST THING about the subject -
> >
> >>> Alas, you don't,
> >
> > [you snipped all of my text that showed you were wrong]
>
> uhhhhh.....
> Let's review this fascinating dialogue.
> I asked why a bike is faster than sneakers, whether peak sprint or distance.
> You retorted (in character): out of the starting blocks, the sprinter wins a
> 100 meter race. Therefore I'm WRONG WRONG WRONG!
>
> Yes, I did snip that, out of courtesy, to avoid embarrassing you.
> To no avail, given your capacity for that activity.

You could try to be honest, for a change,
and reply to -quoted text-
instead of inventing what I might have written.

And yes, you are wrong about it,

Jan

RichD <r_delaney2001@yahoo.com> wrote:
> On April 4, RichD wrote:
>>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>>> Why is a bike faster than Nike?
>>
>> That's a common try: "the gearing acts like a speed amplifier,
>> it gives the cyclist an edge." It's fatally flawed. A gear train and
>> large wheel may be a speed amp, but it isn't a power amp. THAT is the key.
>> So, the biker and runner are identical twins, same metabolism. At any
>> given speed, they face the same air resistance.
>> To maintain constant speed, each must burn as required to overcome the loss
>> at that speed. Their burn rate, when they race, is identical.
>> The bike goes faster because it's more efficient, duh. It suffers lower loss,
>> the runner suffers greater loss. Where exactly is the runner's handicap?
>
> And the solution is ..... <drum roll> ... every time the runner's front foot
> hits the pavement, it STOPS DEAD! It's a colossal kinetic energy waste.
> Then as he pushes off, he has to recover that energy. The cyclist suffers
> nothing comparable.

I’m not sure I buy that.

The wheel patch that comes into contact with the road, also has to meet the
road relatively at rest also, and this is no different than the foot. Good
runners are already pulling back on that foot with the hamstring even while
the foot is in front of the runner’s center of mass.

>
> To make it clearer, picture two sprinters, side by side, one on
> roller skates. What happens when the skater's front foot lands?
> It couldn't be clearer.
>
> An interesting question arises - why can no one answer this question?
> My guess is, walking and running is so deep in our bones, we're numb
> to the stop/start aspect of the activity, it's invisible.
>

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

Odd Bodkin <bodkinodd@gmail.com> wrote:

> RichD <r_delaney2001@yahoo.com> wrote:
> > On April 4, RichD wrote:
> >>>>>> A bicyclist will dust a runner on foot, whether a peak speed
> >>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
> >>>>>> Why is a bike faster than Nike?
> >>
> >> That's a common try: "the gearing acts like a speed amplifier,
> >> it gives the cyclist an edge." It's fatally flawed. A gear train and
> >> large wheel may be a speed amp, but it isn't a power amp. THAT is the key.
> >> So, the biker and runner are identical twins, same metabolism. At any
> >> given speed, they face the same air resistance.
> >> To maintain constant speed, each must burn as required to overcome the loss
> >> at that speed. Their burn rate, when they race, is identical.
> >> The bike goes faster because it's more efficient, duh. It suffers lower
> >> loss, the runner suffers greater loss. Where exactly is the runner's
> >> handicap?
> >
> > And the solution is ..... <drum roll> ... every time the runner's
> > front foot hits the pavement, it STOPS DEAD! It's a colossal kinetic
> > energy waste. Then as he pushes off, he has to recover that energy. The
> > cyclist suffers nothing comparable.
>
> I'm not sure I buy that.

You shouldn't, because it is nonsense.
It is only the 'unsprung weight' (in car terms) that wastes energy.
(so the sole of the shoe)
Walking and running in humans involves a constant exchange
of potential and kinetic energy.
As the leg comes down the kinetic energy is stored
as potential energy in muscles and tendons,
and in compressing or flexing bones.
When the leg extends again most of this energy is restored.

> The wheel patch that comes into contact with the road, also has to meet the
> road relatively at rest also, and this is no different than the foot. Good
> runners are already pulling back on that foot with the hamstring even while
> the foot is in front of the runner's center of mass.

Yes, same story.
And the rubber restitution coeficient isn't ideal either.

Jan

On 4/6/2022 8:47 AM, Odd Bodkin wrote:
> RichD <r_delaney2001@yahoo.com> wrote:
>> On April 4, RichD wrote:
>>>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>>>> Why is a bike faster than Nike?
>>>
>>> That's a common try: "the gearing acts like a speed amplifier,
>>> it gives the cyclist an edge." It's fatally flawed. A gear train and
>>> large wheel may be a speed amp, but it isn't a power amp. THAT is the key.
>>> So, the biker and runner are identical twins, same metabolism. At any
>>> given speed, they face the same air resistance.
>>> To maintain constant speed, each must burn as required to overcome the loss
>>> at that speed. Their burn rate, when they race, is identical.
>>> The bike goes faster because it's more efficient, duh. It suffers lower loss,
>>> the runner suffers greater loss. Where exactly is the runner's handicap?
>>
>> And the solution is ..... <drum roll> ... every time the runner's front foot
>> hits the pavement, it STOPS DEAD! It's a colossal kinetic energy waste.
>> Then as he pushes off, he has to recover that energy. The cyclist suffers
>> nothing comparable.
>
> I’m not sure I buy that.
>
> The wheel patch that comes into contact with the road, also has to meet the
> road relatively at rest also, and this is no different than the foot. Good
> runners are already pulling back on that foot with the hamstring even while
> the foot is in front of the runner’s center of mass.

https://en.wikipedia.org/wiki/Zeno%27s_paradoxes

>> To make it clearer, picture two sprinters, side by side, one on
>> roller skates. What happens when the skater's front foot lands?
>> It couldn't be clearer.
>>
>> An interesting question arises - why can no one answer this question?
>> My guess is, walking and running is so deep in our bones, we're numb
>> to the stop/start aspect of the activity, it's invisible.
>>
>
>
>

whodat <whodaat@void.nowgre.com> wrote:
> On 4/6/2022 8:47 AM, Odd Bodkin wrote:
>> RichD <r_delaney2001@yahoo.com> wrote:
>>> On April 4, RichD wrote:
>>>>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>>>>> Why is a bike faster than Nike?
>>>>
>>>> That's a common try: "the gearing acts like a speed amplifier,
>>>> it gives the cyclist an edge." It's fatally flawed. A gear train and
>>>> large wheel may be a speed amp, but it isn't a power amp. THAT is the key.
>>>> So, the biker and runner are identical twins, same metabolism. At any
>>>> given speed, they face the same air resistance.
>>>> To maintain constant speed, each must burn as required to overcome the loss
>>>> at that speed. Their burn rate, when they race, is identical.
>>>> The bike goes faster because it's more efficient, duh. It suffers lower loss,
>>>> the runner suffers greater loss. Where exactly is the runner's handicap?
>>>
>>> And the solution is ..... <drum roll> ... every time the runner's front foot
>>> hits the pavement, it STOPS DEAD! It's a colossal kinetic energy waste.
>>> Then as he pushes off, he has to recover that energy. The cyclist suffers
>>> nothing comparable.
>>
>> I’m not sure I buy that.
>>
>> The wheel patch that comes into contact with the road, also has to meet the
>> road relatively at rest also, and this is no different than the foot. Good
>> runners are already pulling back on that foot with the hamstring even while
>> the foot is in front of the runner’s center of mass.
>
>
> https://en.wikipedia.org/wiki/Zeno%27s_paradoxes
>
>

Could you elaborate on the relevance you see?

>
>
>>> To make it clearer, picture two sprinters, side by side, one on
>>> roller skates. What happens when the skater's front foot lands?
>>> It couldn't be clearer.
>>>
>>> An interesting question arises - why can no one answer this question?
>>> My guess is, walking and running is so deep in our bones, we're numb
>>> to the stop/start aspect of the activity, it's invisible.
>>>
>>
>>
>>
>
>

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

On April 6, J. J. Lodder wrote:
>>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>>> Why is a bike faster than Nike?
>>>> The bike goes faster because it's more efficient, duh. It suffers lower
>>>> loss, the runner suffers greater loss. Where exactly is the runner's
>>>> handicap?
>>> And the solution is ..... <drum roll> ... every time the runner's
>>> front foot hits the pavement, it STOPS DEAD! It's a colossal kinetic
>>> energy waste. Then as he pushes off, he has to recover that energy. The
>>> cyclist suffers nothing comparable.
> >
>> I'm not sure I buy that.
>
> You shouldn't, because it is nonsense.
> It is only the 'unsprung weight' (in car terms) that wastes energy.
> (so the sole of the shoe)
> Walking and running in humans involves a constant exchange
> of potential and kinetic energy.
> As the leg comes down the kinetic energy is stored
> as potential energy in muscles and tendons,
> and in compressing or flexing bones.
> When the leg extends again most of this energy is restored.

Unbelievable.

The human body isn't a tennis ball!
Kinetic energy isn't "stored as potential energy in the muscles",
it's DISSIPATED.

The jumpers out of the World Trade Center, 2001 - what was
their bounce, at terminal speed?

Furthermore - stringing out your idiotic thesis - if the kinetic
energy COMING DOWN is "stored," it will restore UP. How
does that contribute to FORWARD momentum?

>> The wheel patch that comes into contact with the road, also has to meet the
>> road relatively at rest also, and this is no different than the foot.
>
> Yes, same story.
Same story? Same story?!?!
YOU DON'T EVEN KNOW HOW A WHEEL WORKS!

Yes, the tire, at points of contact with the road, is
"at rest relative to the road", i.e. it doesn't skid;
no skid ==> no friction loss, duh, that's why Allah invented wheels.

But the tire doesn't COMPLETELY HALT ITS FORWARD MOTION,
as does the shoe at contact.

Unbelievable.

--
Rich

RichD <r_delaney2001@yahoo.com> wrote:
> On April 6, J. J. Lodder wrote:
>>>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>>>> Why is a bike faster than Nike?
>>>>> The bike goes faster because it's more efficient, duh. It suffers lower
>>>>> loss, the runner suffers greater loss. Where exactly is the runner's
>>>>> handicap?
>>>> And the solution is ..... <drum roll> ... every time the runner's
>>>> front foot hits the pavement, it STOPS DEAD! It's a colossal kinetic
>>>> energy waste. Then as he pushes off, he has to recover that energy. The
>>>> cyclist suffers nothing comparable.
>>>
>>> I'm not sure I buy that.
>>
>> You shouldn't, because it is nonsense.
>> It is only the 'unsprung weight' (in car terms) that wastes energy.
>> (so the sole of the shoe)
>> Walking and running in humans involves a constant exchange
>> of potential and kinetic energy.
>> As the leg comes down the kinetic energy is stored
>> as potential energy in muscles and tendons,
>> and in compressing or flexing bones.
>> When the leg extends again most of this energy is restored.
>
> Unbelievable.
>
> The human body isn't a tennis ball!
> Kinetic energy isn't "stored as potential energy in the muscles",
> it's DISSIPATED.

Think about this for a second. Consider a tumbling pass by a gymnast, which
concludes with a double-twisting, double-back somersault that is HIGHER
than the person can jump from a standing start. A lot higher. Where do you
think that comes from?

>
> The jumpers out of the World Trade Center, 2001 - what was
> their bounce, at terminal speed?
>
> Furthermore - stringing out your idiotic thesis - if the kinetic
> energy COMING DOWN is "stored," it will restore UP. How
> does that contribute to FORWARD momentum?
>
>>> The wheel patch that comes into contact with the road, also has to meet the
>>> road relatively at rest also, and this is no different than the foot.
>>
>> Yes, same story.
>
> Same story? Same story?!?!
> YOU DON'T EVEN KNOW HOW A WHEEL WORKS!
>
> Yes, the tire, at points of contact with the road, is
> "at rest relative to the road", i.e. it doesn't skid;
> no skid ==> no friction loss, duh, that's why Allah invented wheels.
>
> But the tire doesn't COMPLETELY HALT ITS FORWARD MOTION,
> as does the shoe at contact.

If you run correctly, your foot does not have forward motion at the point
of contact. The leg is fully extended a tenth of a second or so before
contact, and by the time it reaches the ground, the foot is already moving
backwards towards the center of gravity. If this were not true, your shoes
would have a little skid every time the foot made contact with the ground,
as the friction between the foot and the ground slowed the foot to a rest.
This does not happen, hopefully, as it would not only cause severe wear on
shoes, but also on your knee and ankle joints.

>
> Unbelievable.
>
> --
> Rich
>

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

On 4/6/2022 11:17 AM, Odd Bodkin wrote:
> whodat <whodaat@void.nowgre.com> wrote:
>> On 4/6/2022 8:47 AM, Odd Bodkin wrote:
>>> RichD <r_delaney2001@yahoo.com> wrote:
>>>> On April 4, RichD wrote:
>>>>>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>>>>>> Why is a bike faster than Nike?
>>>>>
>>>>> That's a common try: "the gearing acts like a speed amplifier,
>>>>> it gives the cyclist an edge." It's fatally flawed. A gear train and
>>>>> large wheel may be a speed amp, but it isn't a power amp. THAT is the key.
>>>>> So, the biker and runner are identical twins, same metabolism. At any
>>>>> given speed, they face the same air resistance.
>>>>> To maintain constant speed, each must burn as required to overcome the loss
>>>>> at that speed. Their burn rate, when they race, is identical.
>>>>> The bike goes faster because it's more efficient, duh. It suffers lower loss,
>>>>> the runner suffers greater loss. Where exactly is the runner's handicap?
>>>>
>>>> And the solution is ..... <drum roll> ... every time the runner's front foot
>>>> hits the pavement, it STOPS DEAD! It's a colossal kinetic energy waste.
>>>> Then as he pushes off, he has to recover that energy. The cyclist suffers
>>>> nothing comparable.
>>>
>>> I’m not sure I buy that.
>>>
>>> The wheel patch that comes into contact with the road, also has to meet the
>>> road relatively at rest also, and this is no different than the foot. Good
>>> runners are already pulling back on that foot with the hamstring even while
>>> the foot is in front of the runner’s center of mass.
>>
>>
>> https://en.wikipedia.org/wiki/Zeno%27s_paradoxes

> Could you elaborate on the relevance you see?

No. You should be able to figure it out, mathematician that you state
you are.
Did you actually read the cited article?

>>>> To make it clearer, picture two sprinters, side by side, one on
>>>> roller skates. What happens when the skater's front foot lands?
>>>> It couldn't be clearer.
>>>>
>>>> An interesting question arises - why can no one answer this question?
>>>> My guess is, walking and running is so deep in our bones, we're numb
>>>> to the stop/start aspect of the activity, it's invisible.
>>>>
>>>
>>>
>>>
>>
>>
>
>
>

On April 6, bodk...@gmail.com wrote:
>>>>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>>>>> Why is a bike faster than Nike?
> >>>>> The bike goes faster because it's more efficient, duh.
> >>>>> Where exactly is the runner's handicap?
> >>>> And the solution is ..... <drum roll> ... every time the runner's
> >>>> front foot hits the pavement, it STOPS DEAD! It's a colossal kinetic
> >>>> energy waste. Then as he pushes off, he has to recover that energy. The
> >>>> cyclist suffers nothing comparable.
>
>>>> I'm not sure I buy that.
>
>>> Walking and running in humans involves a constant exchange
>>> of potential and kinetic energy.
>>> As the leg comes down the kinetic energy is stored
>>> as potential energy in muscles and tendons,
>>> and in compressing or flexing bones.
>>> When the leg extends again most of this energy is restored.
>
>> The human body isn't a tennis ball!
>> Kinetic energy isn't "stored as potential energy in the muscles",
>> it's DISSIPATED.
>
> Consider a tumbling pass by a gymnast, which concludes with a
> double-back somersault that is HIGHER than the person can jump
> from a standing start. A lot higher. Where do you think that comes from?

Pre-stressing the muscles, priming them.

You're an observant fellow. The gymnasts do get some phenomenal
air. The problem is, your powers of reasoning don't match your powers
of observation.

The human body is 99% viscous. The idea, the explanation, that a gymnast
exploits kinetic --> potential --> kinetic energy conversion, bouncing like a
ball, is preposterous. Gymnastics isn't alchemy, altering the material
properties of the body.

What happens is that after a leap and drop, compressing at the
bottom, the muscles respond extraordinarily; they become stronger,
literally. It's muscular and neural chemistry, not Newton. They
aren't bouncing!

Anyway, this is all a scatterbrain tangent to the debate. Energy
conversion up and down has no relevance to FORWARD momentum!

>>>> The wheel patch that comes into contact with the road, also has to meet the
>>>> road relatively at rest also, and this is no different than the foot.
>>> Yes, same story.
>
>> Same story?
>> YOU DON'T EVEN KNOW HOW A WHEEL WORKS!
>> Yes, the tire, at points of contact with the road, is
>> "at rest relative to the road", i.e. it doesn't skid;
>> no skid ==> no friction loss, duh, that's why Allah invented wheels.
>> But the tire doesn't COMPLETELY HALT ITS FORWARD MOTION,
>> as does the shoe at contact.
>
> If you run correctly, your foot does not have forward motion at the point
> of contact. The leg is fully extended a tenth of a second or so before
> contact, and by the time it reaches the ground, the foot is already moving
> backwards towards the center of gravity. If this were not true, your shoes
> would have a little skid every time the foot made contact with the ground,
> as the friction between the foot and the ground slowed the foot to a rest.

So, let's see...
The foot is moving backward at contact with the road, like a wheel.
Not forward, so there's no loss of speed or kinetic energy.
The foot/road collision does not place extra burden on the runner,
they blend smoothly.
Hence, the runner's cardiovascular output, like the cyclist, goes
entirely into overcoming air and road resistance (and internal losses).
Therefore, bike and Nike travel at the same speed.
QED

I learn something new every day on this board.

Let's delve your thesis deeper, that the shoe is moving backward at impact.

The hip joint moves forward, carried by the torso, relative to the road.
The knee moves forward, relative to the hip, as the leg extends.
The knee flexes a moment before impact, pulling the foot backward,
relative to the knee.
Therefore, since the foot moves backward, relative to the KNEE, it
must also move backward relative to the ROAD!

wow, I'm inspired....
The next time I'm caught in a plane crash, two seconds before impact,
I plan to leap straight up. Moving upward, relative to the plane, means
I'm moving upward relative to the ground (like the foot/knee/road).
Thus I survive, when everybody else splatters.

This could herald a new era in airline safety -

--
Rich

whodat <whodaat@void.nowgre.com> wrote:
> On 4/6/2022 11:17 AM, Odd Bodkin wrote:
>> whodat <whodaat@void.nowgre.com> wrote:
>>> On 4/6/2022 8:47 AM, Odd Bodkin wrote:
>>>> RichD <r_delaney2001@yahoo.com> wrote:
>>>>> On April 4, RichD wrote:
>>>>>>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>>>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>>>>>>> Why is a bike faster than Nike?
>>>>>>
>>>>>> That's a common try: "the gearing acts like a speed amplifier,
>>>>>> it gives the cyclist an edge." It's fatally flawed. A gear train and
>>>>>> large wheel may be a speed amp, but it isn't a power amp. THAT is the key.
>>>>>> So, the biker and runner are identical twins, same metabolism. At any
>>>>>> given speed, they face the same air resistance.
>>>>>> To maintain constant speed, each must burn as required to overcome the loss
>>>>>> at that speed. Their burn rate, when they race, is identical.
>>>>>> The bike goes faster because it's more efficient, duh. It suffers lower loss,
>>>>>> the runner suffers greater loss. Where exactly is the runner's handicap?
>>>>>
>>>>> And the solution is ..... <drum roll> ... every time the runner's front foot
>>>>> hits the pavement, it STOPS DEAD! It's a colossal kinetic energy waste.
>>>>> Then as he pushes off, he has to recover that energy. The cyclist suffers
>>>>> nothing comparable.
>>>>
>>>> I’m not sure I buy that.
>>>>
>>>> The wheel patch that comes into contact with the road, also has to meet the
>>>> road relatively at rest also, and this is no different than the foot. Good
>>>> runners are already pulling back on that foot with the hamstring even while
>>>> the foot is in front of the runner’s center of mass.
>>>
>>>
>>> https://en.wikipedia.org/wiki/Zeno%27s_paradoxes
>
>> Could you elaborate on the relevance you see?
>
>
> No. You should be able to figure it out, mathematician that you state
> you are.
> Did you actually read the cited article?
>
>

Yes, I read it. I also studied the Zeno school in college. This predated
any understanding of convergent infinite series or the calculus.

Did you have a point you were trying to make?

>
>>>>> To make it clearer, picture two sprinters, side by side, one on
>>>>> roller skates. What happens when the skater's front foot lands?
>>>>> It couldn't be clearer.
>>>>>
>>>>> An interesting question arises - why can no one answer this question?
>>>>> My guess is, walking and running is so deep in our bones, we're numb
>>>>> to the stop/start aspect of the activity, it's invisible.
>>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>>
>
>

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

RichD <r_delaney2001@yahoo.com> wrote:
> On April 6, bodk...@gmail.com wrote:
>>>>>>>>> A bicyclist will dust a runner on foot, whether a peak speed
>>>>>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
>>>>>>>>> Why is a bike faster than Nike?
>>>>>>> The bike goes faster because it's more efficient, duh.
>>>>>>> Where exactly is the runner's handicap?
>>>>>> And the solution is ..... <drum roll> ... every time the runner's
>>>>>> front foot hits the pavement, it STOPS DEAD! It's a colossal kinetic
>>>>>> energy waste. Then as he pushes off, he has to recover that energy. The
>>>>>> cyclist suffers nothing comparable.
>>
>>>>> I'm not sure I buy that.
>>
>>>> Walking and running in humans involves a constant exchange
>>>> of potential and kinetic energy.
>>>> As the leg comes down the kinetic energy is stored
>>>> as potential energy in muscles and tendons,
>>>> and in compressing or flexing bones.
>>>> When the leg extends again most of this energy is restored.
>>
>>> The human body isn't a tennis ball!
>>> Kinetic energy isn't "stored as potential energy in the muscles",
>>> it's DISSIPATED.
>>
>> Consider a tumbling pass by a gymnast, which concludes with a
>> double-back somersault that is HIGHER than the person can jump
>> from a standing start. A lot higher. Where do you think that comes from?
>
> Pre-stressing the muscles, priming them.
>
> You're an observant fellow. The gymnasts do get some phenomenal
> air. The problem is, your powers of reasoning don't match your powers
> of observation.
>
> The human body is 99% viscous. The idea, the explanation, that a gymnast
> exploits kinetic --> potential --> kinetic energy conversion, bouncing like a
> ball, is preposterous. Gymnastics isn't alchemy, altering the material
> properties of the body.
>
> What happens is that after a leap and drop, compressing at the
> bottom, the muscles respond extraordinarily; they become stronger,
> literally. It's muscular and neural chemistry, not Newton. They
> aren't bouncing!

Literally stronger, you say. Stronger than what can be applied by will in a
standing jump.
I wonder what makes the muscles stronger! Perhaps you can explain that.

>
> Anyway, this is all a scatterbrain tangent to the debate. Energy
> conversion up and down has no relevance to FORWARD momentum!
>
>>>>> The wheel patch that comes into contact with the road, also has to meet the
>>>>> road relatively at rest also, and this is no different than the foot.
>>>> Yes, same story.
>>
>>> Same story?
>>> YOU DON'T EVEN KNOW HOW A WHEEL WORKS!
>>> Yes, the tire, at points of contact with the road, is
>>> "at rest relative to the road", i.e. it doesn't skid;
>>> no skid ==> no friction loss, duh, that's why Allah invented wheels.
>>> But the tire doesn't COMPLETELY HALT ITS FORWARD MOTION,
>>> as does the shoe at contact.
>>
>> If you run correctly, your foot does not have forward motion at the point
>> of contact. The leg is fully extended a tenth of a second or so before
>> contact, and by the time it reaches the ground, the foot is already moving
>> backwards towards the center of gravity. If this were not true, your shoes
>> would have a little skid every time the foot made contact with the ground,
>> as the friction between the foot and the ground slowed the foot to a rest.
>
> So, let's see...
> The foot is moving backward at contact with the road, like a wheel.

At the point of contact, yes, relative to the body’s center of mass. Not
moving forward relative to the road, no.

> Not forward, so there's no loss of speed or kinetic energy.
> The foot/road collision does not place extra burden on the runner,
> they blend smoothly.
> Hence, the runner's cardiovascular output, like the cyclist, goes
> entirely into overcoming air and road resistance (and internal losses).
> Therefore, bike and Nike travel at the same speed.

Well, no, that’s not the conclusion to be drawn.

> QED
>
> I learn something new every day on this board.
>
> Let's delve your thesis deeper, that the shoe is moving backward at impact.
>
> The hip joint moves forward, carried by the torso, relative to the road.
> The knee moves forward, relative to the hip, as the leg extends.
> The knee flexes a moment before impact, pulling the foot backward,
> relative to the knee.
> Therefore, since the foot moves backward, relative to the KNEE, it
> must also move backward relative to the ROAD!

No, that’s not what I said either. Perhaps the best thing you can do is
look at slow-motion video of a runner, specifically for kinesiology
studies.

>
> wow, I'm inspired....
> The next time I'm caught in a plane crash, two seconds before impact,
> I plan to leap straight up. Moving upward, relative to the plane, means
> I'm moving upward relative to the ground (like the foot/knee/road).
> Thus I survive, when everybody else splatters.
>
> This could herald a new era in airline safety -
>
>
> --
> Rich
>
>

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

RichD <r_delaney2001@yahoo.com> wrote:

> On April 6, J. J. Lodder wrote:
> >>>>>> A bicyclist will dust a runner on foot, whether a peak speed
> >>>>>> sprint, or long distance. Explain this, at the Physics 101 level.
> >>>>>> Why is a bike faster than Nike?
> >>>> The bike goes faster because it's more efficient, duh. It suffers lower
> >>>> loss, the runner suffers greater loss. Where exactly is the runner's
> >>>> handicap?
> >>> And the solution is ..... <drum roll> ... every time the runner's
> >>> front foot hits the pavement, it STOPS DEAD! It's a colossal kinetic
> >>> energy waste. Then as he pushes off, he has to recover that energy. The
> >>> cyclist suffers nothing comparable.
> > >
> >> I'm not sure I buy that.
> >
> > You shouldn't, because it is nonsense.
> > It is only the 'unsprung weight' (in car terms) that wastes energy.
> > (so the sole of the shoe)
> > Walking and running in humans involves a constant exchange
> > of potential and kinetic energy.
> > As the leg comes down the kinetic energy is stored
> > as potential energy in muscles and tendons,
> > and in compressing or flexing bones.
> > When the leg extends again most of this energy is restored.
>
> Unbelievable.
>
> The human body isn't a tennis ball!
> Kinetic energy isn't "stored as potential energy in the muscles",
> it's DISSIPATED.

You really should have a look at a biomechanics textbook.
If your naive idea that the kinetic energy in a downgoing leg
is dissipated on contact with the ground was true
running at speed would be impossible,

Jan

> The jumpers out of the World Trade Center, 2001 - what was
> their bounce, at terminal speed?
>
> Furthermore - stringing out your idiotic thesis - if the kinetic
> energy COMING DOWN is "stored," it will restore UP. How
> does that contribute to FORWARD momentum?
>
> >> The wheel patch that comes into contact with the road, also has to meet the
> >> road relatively at rest also, and this is no different than the foot.
> >
> > Yes, same story.
>
> Same story? Same story?!?!
> YOU DON'T EVEN KNOW HOW A WHEEL WORKS!
>
> Yes, the tire, at points of contact with the road, is
> "at rest relative to the road", i.e. it doesn't skid;
> no skid ==> no friction loss, duh, that's why Allah invented wheels.
>
> But the tire doesn't COMPLETELY HALT ITS FORWARD MOTION,
> as does the shoe at contact.
>
> Unbelievable.
>
> --
> Rich

On April 7, bodk...@gmail.com wrote:
>>>>> Walking and running in humans involves a constant exchange
>>>>> of potential and kinetic energy.
>>>>> As the leg comes down the kinetic energy is stored
>>>>> as potential energy in muscles and tendons,
>>>>> and in compressing or flexing bones.
>>>>> When the leg extends again most of this energy is restored.
>
>>>> The human body isn't a tennis ball!
>>>> Kinetic energy isn't "stored as potential energy in the muscles",
>>>> it's DISSIPATED.
>
>>> Consider a tumbling pass by a gymnast, which concludes with a
>>> double-back somersault that is HIGHER than the person can jump
>>> from a standing start. A lot higher. Where do you think that comes from?
>
>> Pre-stressing the muscles, priming them.
>> The human body is 99% viscous. The idea, the explanation, that a gymnast
>> exploits kinetic --> potential --> kinetic energy conversion, bouncing like a
>> ball, is preposterous. Gymnastics isn't alchemy, altering the material
>> properties of the body.
>> What happens is that after a leap and drop, compressing at the
>> bottom, the muscles respond extraordinarily; they become stronger,
>> literally. It's muscular and neural chemistry, not Newton. They
>> aren't bouncing!
>
> Literally stronger, you say. Stronger than what can be applied by will in a
> standing jump.
> I wonder what makes the muscles stronger! Perhaps you can explain that.

As already mentioned, it's called pre-stressing.

Muscle strength isn't determined by size, but efficiency -
how many muscle fibers can be recruited, by the nerve fibers.
Muscle growth follows from development of nerve fibers,
during training.

In action, it depends on the efficiency of those nerve fibers.
Crouching before the jump, activates more nerves. And
dropping from two feet, into the crouch, activates even more,
as the muscles instinctively cushion the fall, they're pre-stressed.

That's how the gymnasts do it. Not because their bodies magically
turn into hard rubber.

You're welcome.

--
Rich

On April 7, J. J. Lodder wrote:
>> The human body isn't a tennis ball!
>> Kinetic energy isn't "stored as potential energy in the muscles",
>> it's DISSIPATED.
>
> You really should have a look at a biomechanics textbook.
> If your naive idea that the kinetic energy in a downgoing leg
> is dissipated on contact with the ground was true
> running at speed would be impossible,

This grows wearisome.
OK, I guess you haven't studied much physics.

The motion can be decomposed into horizontal and vertical components.

I) Vertical

Fill a sack with lard. Throw it onto the ground. Report back to us
on the observed result.
This is called 'energy dissipation'. Or, using big college words,
zero coefficient of restitution.

II) Horizontal

When an object suddenly STOPS - like the sole of the shoe -
its velocity goes to zero. There's a formula which says its
kinetic energy also goes to zero.

The object may be connected to other objects through
connectors called 'joints'; ankles and knees, to use big
college words, in a complicated structure called the human body.

Those other bits may continue forward motion, their kinetic
energy does not go to zero.

There's something called 'conservation of energy' - that's really
advanced college - which says the bit that stopped must replenish
its kinetic energy, by a process called 'sucrose combustion', which
makes you tired after a while. So eat a bowl of spaghetti before a
10 km race.

A bicyclist's sole doesn't stop, every second. He doesn't get so tired,
and he can go faster.

You're welcome.

--
Rich