[paul cotter]

An early start to countering the bullshit, I salute your dedication and persistence, sir.

[alancalverd]

Let's get back to the windlass.

We have a weightless, frictionless rope around a 0.5 m diameter cylinder that can rotate on frictionless pivots. The moment of inertia of the cylinder is 1 kg.m². We apply a brake, hang a 4 N bucket on the rope, then release the brake.  Conventionally and by common sense the torque is a constant 1 N.m  so the cylinder rotates with a constant angular acceleration of 1 rad/sec². Very reasonable.

But suppose the torque  was 1 N.m/rad. The initial acceleration would be 1 sec^-1, which is, frankly, meaningless, and after one turn (2π rad) the torque would have increased!

[hamdani yusuf (OP)]

It shows that defining 1 radian as dimensionless number with value of 1 is problematic.

Not at all. As the initial figure is 3600 revolutions per minute, the angular speed is (3600/60) x 2π = 377 rad/sec. If you want to know the appropriate strobe frequency for a single mark on a rotating cylinder, it's obviously 3600/60 = 60 Hz.  Where's the problem?

It happens that dividing a circle into 2π radians is more convenient for physics than any other measure of angle, but you could propose a "coherent" standard where a circle has a value of 1. Then the angular speed would be 60 c/sec, the strobe frequency would be 60 Hz, and, for instance, the angle we call π/4 would be 0.125c. So what?

1 Radian in SI is defined as a dimensionless number with value of 1, in order for it to appear and disappear freely in equations like v=ωr, or F=Iα without affecting the numerical value. If you replace it with a constant which doesn't equal 1, you are not following SI's definition of the radian. This implies that you are admitting that SI units for rotational quantities are not perfect.

[hamdani yusuf (OP)]

Let's get back to the windlass.

We have a weightless, frictionless rope around a 0.5 m diameter cylinder that can rotate on frictionless pivots. The moment of inertia of the cylinder is 1 kg.m². We apply a brake, hang a 4 N bucket on the rope, then release the brake.  Conventionally and by common sense the torque is a constant 1 N.m  so the cylinder rotates with a constant angular acceleration of 1 rad/sec². Very reasonable.

But suppose the torque  was 1 N.m/rad. The initial acceleration would be 1 sec^-1, which is, frankly, meaningless, and after one turn (2π rad) the torque would have increased!

You are confused because you are mixing SI unit for angular inertia with the equationally consistent unit for angular force.

[hamdani yusuf (OP)]

As promised in previous video, now we will discuss about causes of the problems in current SI units for rotational quantities.

[paul cotter]

Post #1181 by Alan is entirely consistent and if you cannot see that you are more confused than I had previously thought. Or maybe you are being deliberately obstinate because you have been soundly proved to be in error and you can't accept reality.

[alancalverd]

1 Radian in SI is defined as a dimensionless number with value of 1

No.

The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI) and is the standard unit of angular measure used in many areas of mathematics. It is defined such that one radian is the angle subtended at the centre of a circle by an arc that is equal in length to the radius.[2] The unit was formerly an SI supplementary unit and is currently a dimensionless SI derived unit,[2] defined in the SI as 1 rad = 1[3] and expressed in terms of the SI base unit metre (m) as rad = m/m.[4] Angles without explicitly specified units are generally assumed to be measured in radians, especially in mathematical writing.

If you stick to the facts, you won't be confused by your own fantasies!

[alancalverd]

You are confused because you are mixing SI unit for angular inertia with the equationally consistent unit for angular force.

Me confused? Surely  α = τ/I. All I have done is substitute your proposed unit of τ.

[paul cotter]

Hamdani  is so confused by basic science that he thinks those who understand these matters are themselves confused!  My advice to anyone who wishes to challenge accepted science: you must fully understand the existing understanding before attempting to mount a challenge. Hamdani falls well short of this basic requirement.

[hamdani yusuf (OP)]

Post #1181 by Alan is entirely consistent and if you cannot see that you are more confused than I had previously thought. Or maybe you are being deliberately obstinate because you have been soundly proved to be in error and you can't accept reality.

Can you identify an error in my derivation video?
You can watch it in Reply #1173

[hamdani yusuf (OP)]

1 Radian in SI is defined as a dimensionless number with value of 1

No.

The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI) and is the standard unit of angular measure used in many areas of mathematics. It is defined such that one radian is the angle subtended at the centre of a circle by an arc that is equal in length to the radius.[2] The unit was formerly an SI supplementary unit and is currently a dimensionless SI derived unit,[2] defined in the SI as 1 rad = 1[3] and expressed in terms of the SI base unit metre (m) as rad = m/m.[4] Angles without explicitly specified units are generally assumed to be measured in radians, especially in mathematical writing.

If you stick to the facts, you won't be confused by your own fantasies!

I do think that you should be consistent in deriving units of physical quantities according to all relevant definitions and equations.
In equation v = ωr,
According to current SI, if
v = 1 m/s
ω = 1 rad/s
r = 1 m
then

ωr = 1 m.rad/s
--> 1 m/s = 1 m.rad/s
1 rad = 1 (unitless)

How do you fix this?

[hamdani yusuf (OP)]

You are confused because you are mixing SI unit for angular inertia with the equationally consistent unit for angular force.

Me confused? Surely  α = τ/I. All I have done is substitute your proposed unit of τ.

You also have to substitute the unit for angular inertia.
Otherwise, the radian on the left hand side of the equation ghostly appear or disappear from the right hand side of the equation, like in current SI system.

[hamdani yusuf (OP)]

Let's get back to the windlass.

We have a weightless, frictionless rope around a 0.5 m diameter cylinder that can rotate on frictionless pivots. The moment of inertia of the cylinder is 1 kg.m². We apply a brake, hang a 4 N bucket on the rope, then release the brake.  Conventionally and by common sense the torque is a constant 1 N.m  so the cylinder rotates with a constant angular acceleration of 1 rad/sec². Very reasonable.

But suppose the torque  was 1 N.m/rad. The initial acceleration would be 1 sec^-1, which is, frankly, meaningless, and after one turn (2π rad) the torque would have increased!

You are confused because you are mixing SI unit for angular inertia with the equationally consistent unit for angular force.

I hope the table below can help you understand and remember the proposed unit system for rotational quantities. It's a preview from my next video to cover more general type of rotational motion, where the radial component is not necessarily zero.

[alancalverd]

Oh dear. You have equated force and torque.
What do you mean by "radial" units?
Everyone else uses watts for power.
Whish is why we don't like using W to signify anything else
You haven't given a derivation for "angular work" or "radial work".
and so forth

Around 50 years ago my colleague Christine  and I were building a radiation calorimeter, capable of measuring one microdegree temperature change, using what was then the most advanced analog electronics, programmable phase-locked arbitrary waveform generators, turbomolecular pumps with electronic vacuum gauges, and PID ambient temperature control systems, all either our own design or hot off the manufacturer's next-year catalog. We shared a birthday, so we used to laugh at our daily horoscope. The day we came to switch it all on, we read: "Capricorn - It is better to leave electrical work to an expert."

I commend the astrologer's advice to the honorable gentleman: leave SI standards to those who understand physics.

[alancalverd]

How do you fix this?

By understanding the meaning of rad, and knowing that v = ds/dt, ω = dθ/dt and s = rθ.

[hamdani yusuf (OP)]

Oh dear. You have equated force and torque.
What do you mean by "radial" units?
Everyone else uses watts for power.
Whish is why we don't like using W to signify anything else
You haven't given a derivation for "angular work" or "radial work".
and so forth

Around 50 years ago my colleague Christine  and I were building a radiation calorimeter, capable of measuring one microdegree temperature change, using what was then the most advanced analog electronics, programmable phase-locked arbitrary waveform generators, turbomolecular pumps with electronic vacuum gauges, and PID ambient temperature control systems, all either our own design or hot off the manufacturer's next-year catalog. We shared a birthday, so we used to laugh at our daily horoscope. The day we came to switch it all on, we read: "Capricorn - It is better to leave electrical work to an expert."

I commend the astrologer's advice to the honorable gentleman: leave SI standards to those who understand physics.

Angular work is the integral of angular force with respect to angular displacement.
It's analogous to tangential work, which is the integral of tangential force with respect to tangential displacement.
As mentioned in my video, time and energy are anchoring units, where their tangential and angular types are the same. The other angular quantities are derived from them. My derivation video has shown the process step by step thoroughly that average high school students would be able to follow.

You shouldn't follow astrologer's advice.

[hamdani yusuf (OP)]

How do you fix this?

By understanding the meaning of rad, and knowing that v = ds/dt, ω = dθ/dt and s = rθ.

Let's take a simple system with a constant rotational radius and angular velocity.
v = 1 m/s
ω = 1 rad/s
thus r = 1 m, according to SI
for every t = 1 s,
θ = 1 radian
s = 1 m

The equation
s = rθ
Leads to the conclusion
1 m = 1 m . 1 rad
1 rad = 1

On the other hand,
2π rad/s = 1 cycle/second = 1 Hz = 1/s
which leads to
1 rad = 1/(2π)
A contradiction as shown by the Quora user I quoted in reply #1178

[hamdani yusuf (OP)]

Dietrich Bonhoeffer's WARNING on the Terrifying Theory of Stupidity

The Terrible Truth About Human Stupidity ? Bonhoeffer?s Forgotten Warning
Is stupidity less about a lack of intelligence and more about a refusal to think?

In this thought-provoking and educational video essay, we explore theologian and philosopher Dietrich Bonhoeffer?s powerful warning about human stupidity ? a social and psychological phenomenon that goes far beyond individual ignorance.

🔎 What you?ll discover:
✅ Why even intelligent people can support destructive ideas
✅ How groupthink, social pressure and conformity affect the collective psyche
✅ Practical tools for maintaining your intellectual independence amid the avalanche of misinformation

Using an in-depth analysis that combines philosophy, psychology, neuroscience and media, we investigate how stupidity can manifest itself in modern societies, fueled by information bubbles, algorithms and ideological manipulations.

💡 This video is an invitation to critical thinking, self-awareness, and active resistance to blind conformity ? a timely call in a world increasingly saturated with noise and superficiality.

🧠 Key themes:

Collective stupidity and individual responsibility

Mass manipulation and social behavior

The human psyche in the face of authority and misinformation

Bonhoeffer, Hannah Arendt, and the risks of passive thinking

🗣️ Bonhoeffer's reflection:

?Against stupidity, we are defenseless.?

An urgent reminder: resisting organized stupidity is one of the greatest responsibilities of the free individual.

💬 Question for you:
What belief or idea are you willing to question this week? Comment below ? let's reflect together.

👍 If you value content that stimulates the mind and spirit, like, subscribe, and share with someone who is ready to think beyond the obvious.

⸻
📌 Keywords: human stupidity, psyche, Bonhoeffer, conformism, misinformation, critical thinking, social manipulation, political philosophy, social psychology, collective intelligence, individual responsibility

📢 Disclaimer:
This video is for educational and informative purposes only. We do not promote or glorify historical regimes, harmful ideologies or any form of intolerance. All references are made for analysis, reflection and learning. We repudiate any expression of hatred, discrimination or violence.

[hamdani yusuf (OP)]

A history of mad attempts to fix English spelling

English spelling is broken. Often the letters we write down on the page bear little resemblance to the words we say out loud. Many attempts have been made to fix this, by medieval monks and American presidents. So let's investigate some of these attempts and find out why they failed.

Can English spelling be fixed, or is it doomed to remain nightmare for learners? Let's find out.


#spelling #english #linguistics

==CHAPTERS==
0:00 Introduction
0:22 The problem with English
1:26 Orrmin the monnk
5:24 N4mbers for vowels
10:13 N8mbers for everything
12:35 Noah Webster
14:29 Benjamin Franklin
15:11 President Theodore Roosevelt
17:00 Why change failed
14:48 Is spelling changing?
19:55 Should it change?

Consistency doesn't seem to be the human's particular strength.

[alancalverd]

2π rad/s = 1 cycle/second = 1 Hz = 1/s

Only in the specific case of continuous circular motion, which you have not stated. A standard instrument turn in an airplane is π rad/minute, but you couldn't call it 0.052 Hz unless you are in a spin or spiral dive, which is not a happy place to be.

English spelling is broken.

Inappropriate use of "broken". English spelling is interesting because the words have many historical sources and there is no official body to limit the vocabulary, which makes it a very robust and flexible language, but it's no more of a "nightmare" than Chinese. You just have to learn the words individually. If you want to use a language whose spelling and pronunciation are always logical and consistent, you can use German. But for some reason, more folk prefer English.

What belief or idea are you willing to question this week?

Any and every belief that is not supported by observation.

Consistency doesn't seem to be the human's particular strength.

Consistency can be weakness. Evolution and adaptability work better in a dynamic world. Otherwise we'd be stuck with Genesis, phlogiston, and an ultraviolet catastrophe. Farseebox (all Saxon roots, consistent pronunciation, like Fernsehapparat) or television (Latin/Greek bastard word that everyone uses)? Mind you, my favorite word of all time was written on the HT rectifier of an old German valve television: "Fernsehapparathochspannunggleichricter" - absolutely logical!