YouTube - We Still Don’t Know How Bicycles Work

On Tuesday, January 26, 2021 at 10:47:54 AM UTC-8, Bertrand wrote:
Steve, did you notice the part that said, "This calculator is designed to give the approximate circumference of any ellipse."? There is no formula for finding the circumference of an oval. Mathematics like most other sciences are limited in scope. We cannot even measure the actual orbit of the Earth after how many millennia?

Yes, but it seems good enough for "Government Work" ;-)
Sort of irritating that it says "approximate" without indicating *how* approximate.
There's a more accurate formula he https://sciencing.com/calculate-circ...l-5948695.html
Science may have its limitations, but it's the best tool we have for finding out how stuff works.
First of all, "oval" is an imprecise term. Not all ovals are ellipses. A
typical oval race track, for example, is not an ellipse, and it's easy to
calculate its circumference.

Concerning ellipses, there are absolutely exact formulas for the circumference:

https://en.wikipedia.org/wiki/Ellipse#Circumference

The formulas are not in simple closed form, but that doesn't mean that they
don't exist, or that the problem is somehow beyond the scope of mathematics. If
understanding or implementing a mathematical solution is beyond the capabilities
of a particular individual, that's a different issue.
https://www.askdifference.com/oval-v...ess%20than%201. There is NO mathematical formula that can give a precise circumference of an oval/ellipse.

Your statements are rather a curiosity since all of the mathematics texts I have read are quite specific that you can have a close but not precise circumference of an oval. i.e. "An oval looks like an elongated circle and is most commonly called an ellipse in geometry. Although there is no single, simple formula for calculating the circumference of an ellipse, one formula is more accurate than others."

That this is true is beyond question. And the equally invalid statement that "we don't know how a bicycle works" is also untrue. Bicycles with geometry outside of normal values are balanced by the rider. They are forced by muscular power of the rider to operate inside of those normal values. These bicycles will NOT balance themselves without a human doing so. Inside of normal values the stability of a bicycle runs from almost unstable (many rapidly acting racing bikes) to completely stable at speed so that a rider can ride them even around corners simply by leaning his weight. Of course ALL of this requires traction so you absolutely cannot balance a bike on surfaces without traction any more than a man can walk on surfaces without traction..

On Tuesday, January 26, 2021 at 11:58:26 AM UTC-8, AMuzi wrote:
On 1/26/2021 12:29 PM, Tom Kunich wrote:
On Tuesday, January 26, 2021 at 10:22:31 AM UTC-8, Steve Weeks wrote:
Steve, did you notice the part that said, "This calculator is designed to give the approximate circumference of any ellipse."? There is no formula for finding the circumference of an oval. Mathematics like most other sciences are limited in scope. We cannot even measure the actual orbit of the Earth after how many millennia?
Yes, but it seems good enough for "Government Work" ;-)
Sort of irritating that it says "approximate" without indicating *how* approximate.
There's a more accurate formula he https://sciencing.com/calculate-circ...l-5948695.html
Science may have its limitations, but it's the best tool we have for finding out how stuff works.
I should add that a part of what is called "man made climate change" is due almost entirely to the elliptical orbit of the Earth about the Sun and the manner of the Earth being tilted on its axis in relation to the Sun.

First you wrote 'oval' meaning 'ellipse'. Those are
different things (ellipses being a small subset of ovals) in
terms of Euclidean geometry.

I don't know what you mean by orbit but it's surely not an
actual ellipse.

Well, you can describe it that way, an ellipse is incomplete oval that has exactly the same mathematical problem as an oval.

On 1/26/2021 3:00 PM, AMuzi wrote:
On 1/26/2021 1:39 PM, Frank Krygowski wrote:
On 1/26/2021 1:47 PM, Bertrand wrote:
Steve, did you notice the part that said, "This
calculator is designed to give the approximate
circumference of any ellipse."? There is no formula for
finding the circumference of an oval. Mathematics like
most other sciences are limited in scope. We cannot even
measure the actual orbit of the Earth after how many
millennia?

Yes, but it seems good enough for "Government Work" ;-)
Sort of irritating that it says "approximate" without
indicating *how* approximate.
There's a more accurate formula he
https://sciencing.com/calculate-circ...l-5948695.html

Science may have its limitations, but it's the best tool
we have for finding out how stuff works.

First of all, "oval" is an imprecise term.Â* Not all ovals
are ellipses. A typical oval race track, for example, is
not an ellipse, and it's easy to calculate its circumference.

Concerning ellipses, there are absolutely exact formulas
for the circumference:

https://en.wikipedia.org/wiki/Ellipse#Circumference

The formulas are not in simple closed form, but that
doesn't mean that they don't exist, or that the problem is
somehow beyond the scope of mathematics.Â* If
understanding or implementing a mathematical solution is
beyond the capabilities of a particular individual, that's
a different issue.

Let me add that my ancient bound copy of _Standard Handbook
for Mechanical Engineers_ (AKA Marks' Handbook) has on page
2-18 "Length of perimeter of ellipse..." followed by three
pretty simple formulas. The trick is, the equation defining
one constant K is a converging infinite series.

The Handbook doesn't even blink an eye at this, figuratively
speaking. In practice, you simply evaluate K using as many
terms as necessary to generate the accuracy you need. This
is perfectly acceptable, because in the real physical world
nothing is measured or manufactured to absolute perfection.

However, infinite series may be incomprehensible to those
with, shall we say, limited education. I imagine the concept
of Pi must also be baffling to those people. ("You mean it
goes on forever??? That means we don't know it's value!!!")


Well then, you're not approaching the problem correctly!

https://rationalwiki.org/wiki/Indiana_Pi_Bill

Yes, I heard of that befo "Let's pass a law defining Pi = 3.2000" The
Indiana House did pass it, in 1897. Luckily, it got no further.

Anyone want to guess which political party dominated Indiana when that
happened? ;-)

https://en.wikipedia.org/wiki/Politi...gth_in_Indiana


--
- Frank Krygowski

On Tue, 26 Jan 2021 08:35:23 -0800, Tom Kunich scribed:

On Monday, January 25, 2021 at 5:17:55 PM UTC-8, Steve Weeks wrote:
On Monday, January 25, 2021 at 3:44:02 PM UTC-6,
wrote:

Why don't you tell us about that math that can measure the
circumference of an oval?
Google is your friend: the formula is PI * SquareRoot of 2 * ((1/2 long
axis)squared + (1/2 short axis)squared).
Or even easier:
http://www.csgnetwork.com/
circumellipse.html#:~:text=The%20circumference%20i s%20in%20whatever,
2%20short%20axis)squared).
Steve, did you notice the part that said, "This calculator is designed
to give the approximate circumference of any ellipse."? There is no
formula for finding the circumference of an oval.

You have been given a formula.

Mathematics like most
other sciences are limited in scope.

What you forgot to specify in your initial request is the degree of
accuracy you are now seeking to impose. It s called changing the goal
posts. If your claim is true, then bicycle frames made from val tube
would have been impossible to build.


We cannot even measure the actual
orbit of the Earth after how many millennia?

Yet, over all those exact same millennia, humans have been able to
return to their starting point of a journey. astronauts have been to the
mon and back and funny little tonka trucks have collected and returned
samples from various asteroids, etc from with in out solar system and
even 'dumb space junk; is now cicling the sun and doing the same.

So like a lot of your posts, you are again incorrect.

On Tue, 26 Jan 2021 10:29:18 -0800, Tom Kunich scribed:

On Tuesday, January 26, 2021 at 10:22:31 AM UTC-8, Steve Weeks wrote:
Steve, did you notice the part that said, "This calculator is
designed to give the approximate circumference of any ellipse."?
There is no formula for finding the circumference of an oval.
Mathematics like most other sciences are limited in scope. We cannot
even measure the actual orbit of the Earth after how many millennia?
Yes, but it seems good enough for "Government Work" ;-)
Sort of irritating that it says "approximate" without indicating *how*
approximate.
There's a more accurate formula he
https://sciencing.com/calculate-circ...l-5948695.html Science
may have its limitations, but it's the best tool we have for finding
out how stuff works.
I should add that a part of what is called "man made climate change" is
due almost entirely to the elliptical orbit of the Earth about the Sun
and the manner of the Earth being tilted on its axis in relation to the
Sun.

Oh, decisions, decisions.
Always someone with an opinion.
Who should one believe? That David Attenborough fellow or that school
drop out with no further study or qualifications; little tommy.

https://www.imdb.com/title/tt11989890/
David Attenborourgh; a Life on Our Planet

Am 25.01.2021 um 22:44 schrieb Tom Kunich:
On Monday, January 25, 2021 at 10:57:32 AM UTC-8, Frank Krygowski
wrote:

But a warning: Those guys use math.
Why don't you tell us about that math that can measure the
circumference of a oval?

Math does not "measure" but "calculate". Before you can start using
math, you need a precise description what you mean by "oval" (and as
soon as you give a precise definition, someboda can find a formula for
its circumference).

The simplest version of an oval (also called "stadium" according to
wikipedia) is a circle cut through in the middle where the halves are
connected by straight lines, so it is defined by
r = "Radius of each semi-circle"
a = "distance between the two centers of the semi-circles"

https://en.wikipedia.org/wiki/Stadium_(geometry)

For this oval, the formula is quite simply
2( pi * r + a)

On Tuesday, January 26, 2021 at 5:52:19 PM UTC-8, Frank Krygowski wrote:
On 1/26/2021 3:00 PM, AMuzi wrote:
On 1/26/2021 1:39 PM, Frank Krygowski wrote:
On 1/26/2021 1:47 PM, Bertrand wrote:
Steve, did you notice the part that said, "This
calculator is designed to give the approximate
circumference of any ellipse."? There is no formula for
finding the circumference of an oval. Mathematics like
most other sciences are limited in scope. We cannot even
measure the actual orbit of the Earth after how many
millennia?

Yes, but it seems good enough for "Government Work" ;-)
Sort of irritating that it says "approximate" without
indicating *how* approximate.
There's a more accurate formula he
https://sciencing.com/calculate-circ...l-5948695.html

Science may have its limitations, but it's the best tool
we have for finding out how stuff works.

First of all, "oval" is an imprecise term. Not all ovals
are ellipses. A typical oval race track, for example, is
not an ellipse, and it's easy to calculate its circumference.

Concerning ellipses, there are absolutely exact formulas
for the circumference:

https://en.wikipedia.org/wiki/Ellipse#Circumference

The formulas are not in simple closed form, but that
doesn't mean that they don't exist, or that the problem is
somehow beyond the scope of mathematics. If
understanding or implementing a mathematical solution is
beyond the capabilities of a particular individual, that's
a different issue.

Let me add that my ancient bound copy of _Standard Handbook
for Mechanical Engineers_ (AKA Marks' Handbook) has on page
2-18 "Length of perimeter of ellipse..." followed by three
pretty simple formulas. The trick is, the equation defining
one constant K is a converging infinite series.

The Handbook doesn't even blink an eye at this, figuratively
speaking. In practice, you simply evaluate K using as many
terms as necessary to generate the accuracy you need. This
is perfectly acceptable, because in the real physical world
nothing is measured or manufactured to absolute perfection.

However, infinite series may be incomprehensible to those
with, shall we say, limited education. I imagine the concept
of Pi must also be baffling to those people. ("You mean it
goes on forever??? That means we don't know it's value!!!")


Well then, you're not approaching the problem correctly!

https://rationalwiki.org/wiki/Indiana_Pi_Bill
Yes, I heard of that befo "Let's pass a law defining Pi = 3.2000" The
Indiana House did pass it, in 1897. Luckily, it got no further.

Anyone want to guess which political party dominated Indiana when that
happened? ;-)

https://en.wikipedia.org/wiki/Politi...gth_in_Indiana

Le me get this straight, since you cannot argue that we "still don't know how a bicycle works" you want to talk about laws made in the 1800's? Why don't you tell us that the law that Indiana passed that forbid girls riding to schools on bicycles because they might show some panties was because of the political party and not because people in Indiana are crazy? You have reached a level displaying your stupidity that makes it clear why I've never met a mechanical engineer from Indiana.

On Wednesday, January 27, 2021 at 1:34:38 AM UTC-8, Rolf Mantel wrote:
Am 25.01.2021 um 22:44 schrieb Tom Kunich:
On Monday, January 25, 2021 at 10:57:32 AM UTC-8, Frank Krygowski
wrote:

But a warning: Those guys use math.
Why don't you tell us about that math that can measure the
circumference of a oval?
Math does not "measure" but "calculate". Before you can start using
math, you need a precise description what you mean by "oval" (and as
soon as you give a precise definition, someboda can find a formula for
its circumference).

The simplest version of an oval (also called "stadium" according to
wikipedia) is a circle cut through in the middle where the halves are
connected by straight lines, so it is defined by
r = "Radius of each semi-circle"
a = "distance between the two centers of the semi-circles"

https://en.wikipedia.org/wiki/Stadium_(geometry)

For this oval, the formula is quite simply
2( pi * r + a)

On Wednesday, January 27, 2021 at 1:34:38 AM UTC-8, Rolf Mantel wrote:
Am 25.01.2021 um 22:44 schrieb Tom Kunich:
On Monday, January 25, 2021 at 10:57:32 AM UTC-8, Frank Krygowski
wrote:

But a warning: Those guys use math.
Why don't you tell us about that math that can measure the
circumference of a oval?
Math does not "measure" but "calculate". Before you can start using
math, you need a precise description what you mean by "oval" (and as
soon as you give a precise definition, someboda can find a formula for
its circumference).

The simplest version of an oval (also called "stadium" according to
wikipedia) is a circle cut through in the middle where the halves are
connected by straight lines, so it is defined by
r = "Radius of each semi-circle"
a = "distance between the two centers of the semi-circles"

https://en.wikipedia.org/wiki/Stadium_(geometry)

For this oval, the formula is quite simply
2( pi * r + a)
Please do not argue the meanings of words when you know what is meant. And do not take a single special case that can be measured accurately and pretend that it is fitting for all cases. Tell us the perimeter of the orbit of Pluto and then we can see your accuracies?

On 1/27/2021 12:19 PM, Tom Kunich wrote:
On Wednesday, January 27, 2021 at 1:34:38 AM UTC-8, Rolf Mantel wrote:
Am 25.01.2021 um 22:44 schrieb Tom Kunich:
On Monday, January 25, 2021 at 10:57:32 AM UTC-8, Frank Krygowski
wrote:

But a warning: Those guys use math.
Why don't you tell us about that math that can measure the
circumference of a oval?
Math does not "measure" but "calculate". Before you can start using
math, you need a precise description what you mean by "oval" (and as
soon as you give a precise definition, someboda can find a formula for
its circumference).

The simplest version of an oval (also called "stadium" according to
wikipedia) is a circle cut through in the middle where the halves are
connected by straight lines, so it is defined by
r = "Radius of each semi-circle"
a = "distance between the two centers of the semi-circles"

https://en.wikipedia.org/wiki/Stadium_(geometry)

For this oval, the formula is quite simply
2( pi * r + a)
Please do not argue the meanings of words when you know what is meant. And do not take a single special case that can be measured accurately and pretend that it is fitting for all cases. Tell us the perimeter of the orbit of Pluto and then we can see your accuracies?


A planet's orbit is variable because it is affected by the
various motions, masses and distances of the other planets,
other smaller crud, its own wobble and so on.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971