[paul cotter]

That's fine by me, BC, I certainly take your word for it.

[hamdani yusuf (OP)]

List of authors in a creation of international standards.

Is there such a list available?

Is the new standard document anonymous? Or worse, undocumented?

[alancalverd]

The International Electrotechnical Commission standards I worked on are traceable to Working Groups, whose composition changes from time to time. I guess you could refer to WG minutes if you really cared, but the fact that that are adopted by manufacturers for international trade is what matters: if they are incompatible or unworkable, or in some way transgress the laws of physics, they get updated as required.

[Bored chemist]

Is the new standard document anonymous? Or worse, undocumented?

Pick an ISO standard and try to find out who wrote it.

[hamdani yusuf (OP)]

Why the radian doesn't show up in the unit of power?

Because it is irrelevant. A watt is a watt.

It failed the basic unit analysis.
If non-standard units were used, you will get wrong results.
Power equals torque times angular velocity.
1 Joule per second equals 1 Joule per radian times 1 radian per second.
1 Joule per second equals 1 Joule per degree times 1 degree per second.
Likewise, distance equals velocity times time.
If you walk at 1 meter per second for one second, you cover 1 meter distance.
If you walk at 1 mile per hour for one hour, you cover 1 mile distance.
You should be able to convert the unit before you calculate the numbers, or after the calculation.

[hamdani yusuf (OP)]

To change a standard, saying that everyone is wrong isn't enough. It needs to be supported by strong evidence and argumentation to demonstrate that the new standard is more useful than the old one.

And you have not got close to doing that.

A thousand miles journey starts with a single step.

Only if it's in the right direction.

The proposed new standards are directed to more consistent units according to unit analysis.
The gradient descent method shows that if you know that current position is suboptimal, a random step to any direction is often better than staying still, as long as there is a correct feedback mechanism.

[alancalverd]

The proposed new standards are directed to more consistent units according to unit analysis.

If you mean dimensional analysis, it doesn't help at all.

I think you (and maybe others) have been misled by the notion of "rotational analogs of linear quantities".

[hamdani yusuf (OP)]

The proposed new standards are directed to more consistent units according to unit analysis.

If you mean dimensional analysis, it doesn't help at all.

No. It's unit analysis. If you use miles instead of kilometer, you must include the conversion factor.

[hamdani yusuf (OP)]

I think you (and maybe others) have been misled by the notion of "rotational analogs of linear quantities".

I think you (and maybe others) have been misled by the deceptively simple formula for torque, without considering that it's correlated to other rotational quantities. As I mentioned in my video, torque is only one third of rotational quantities with problematic standard units. The other two are angular momentum and rotational inertia.

[Bored chemist]

as long as there is a correct feedback mechanism..

We give you the feedback.
It doesn't seem to help.

Pick an ISO standard and try to find out who wrote it.

[hamdani yusuf (OP)]

Kinetic energy of a spinning object is the sum of its parts.
Ek = 1/2 m. v^2 = 1/2 I. ω^2
I= m. v^2/(ω^2)
Thus any unit of rotational inertia must contain unit for mass, square of unit for length, and inverse of square of unit for angle, since the time unit cancels out. In SI it's kg.m^2/rad^2.

Here's some examples of valid but non-standard unit for rotational inertia,
ounce.inch^2/degree^2
ounce.inch^2/sextant^2
kg.m^2/rotation^2
kg.m^2/zam^2

[hamdani yusuf (OP)]

as long as there is a correct feedback mechanism..

We give you the feedback.
It doesn't seem to help.

Pick an ISO standard and try to find out who wrote it.

What should be changed in my proposed new standard units for rotational quantities? Why do you think the changes are necessary?

[Bored chemist]

What should be changed in my proposed new standard units for rotational quantities?

It should be deleted.

Why do you think the changes are necessary?

Because the proposals serve no purpose.

[Bored chemist]

Quote from: Bored chemist on 04/03/2025 18:36:30
Pick an ISO standard and try to find out who wrote it.

[hamdani yusuf (OP)]

You, Hamdani, have fallen into delusions of grandeur, thinking that you are smarter than the current body of scientific discipline.

You have fallen into a logical fallacy called argument from authority.

No.
There's nothing wrong with recognising the authority of authorities.

Recognizing doesn't mean always agree blindly without question. It has some value for making decisions, especially if we don't have the first hand information ourselves.

As a kid, I first learned about torque and its usage in static systems, where angular momentum and rotational inertia can be ignored. Current standard unit for torque didn't seem to cause any problem.
But when dynamic system is involved, angular momentum and rotational inertia can NOT be ignored anymore. That's when I had a suspicion that unit analysis of torque, angular momentum, and rotational inertia were problematic.

[hamdani yusuf (OP)]

What should be changed in my proposed new standard units for rotational quantities?

It should be deleted.

Why do you think the changes are necessary?

Because the proposals serve no purpose.

You might have failed to see the purpose of the new standard units because you never have to use them to solve your problems. But someone else do use them and need more consistent units. Some of them may prefer to use non-standard units, e.g. when the rotational angle is very small or very large (multiple turns).

[hamdani yusuf (OP)]

https://en.wikipedia.org/wiki/Angle#Dimensional_analysis
Plane angle may be defined as θ = s/r, where θ is the magnitude in radians of the subtended angle, s is circular arc length, and r is radius. One radian corresponds to the angle for which s = r, hence 1 radian = 1 m/m = 1.[9] However, rad is only to be used to express angles, not to express ratios of lengths in general.[7] A similar calculation using the area of a circular sector θ = 2A/r2 gives 1 radian as 1 m2/m2 = 1.[10] The key fact is that the radian is a dimensionless unit equal to 1. In SI 2019, the SI radian is defined accordingly as 1 rad = 1.[11] It is a long-established practice in mathematics and across all areas of science to make use of rad = 1.[4][12]

Giacomo Prando writes "the current state of affairs leads inevitably to ghostly appearances and disappearances of the radian in the dimensional analysis of physical equations".[13] For example, an object hanging by a string from a pulley will rise or drop by y = rθ centimetres, where r is the magnitude of the radius of the pulley in centimetres and θ is the magnitude of the angle through which the pulley turns in radians. When multiplying r by θ, the unit radian does not appear in the product, nor does the unit centimetre?because both factors are magnitudes (numbers). Similarly in the formula for the angular velocity of a rolling wheel, ω = v/r, radians appear in the units of ω but not on the right hand side.[14] Anthony French calls this phenomenon "a perennial problem in the teaching of mechanics".[15] Oberhofer says that the typical advice of ignoring radians during dimensional analysis and adding or removing radians in units according to convention and contextual knowledge is "pedagogically unsatisfying".[16]

In 1993 the American Association of Physics Teachers Metric Committee specified that the radian should explicitly appear in quantities only when different numerical values would be obtained when other angle measures were used, such as in the quantities of angle measure (rad), angular speed (rad/s), angular acceleration (rad/s2), and torsional stiffness (N⋅m/rad), and not in the quantities of torque (N⋅m) and angular momentum (kg⋅m2/s).[17]

At least a dozen scientists between 1936 and 2022 have made proposals to treat the radian as a base unit of measurement for a base quantity (and dimension) of "plane angle".[18][19][20] Quincey's review of proposals outlines two classes of proposal. The first option changes the unit of a radius to meters per radian, but this is incompatible with dimensional analysis for the area of a circle, πr2. The other option is to introduce a dimensional constant. According to Quincey this approach is "logically rigorous" compared to SI, but requires "the modification of many familiar mathematical and physical equations".[21] A dimensional constant for angle is "rather strange" and the difficulty of modifying equations to add the dimensional constant is likely to preclude widespread use.[20]

It's obvious that I'm not the only one who's not satisfied by the current standard units for some rotational quantities for their inconsistencies with each other. The problem has already been identified at least since 1936, although no satisfying solution has been found.
The first option is to change the unit of a radius to meters per radian, but this creates new incompatibility. It was rejected in favor of keeping the old incompatibilities instead. It seems like human thought has its own version of inertia.
These incompatibilities can be eliminated by making a distinction between geometric radius and rotational radius. While geometric radius is still measured in meter, rotational radius is measured in meter per radian because it represents the ratio between arc length of the rotational motion and its angular distance.

[alancalverd]

No. It's unit analysis. If you use miles instead of kilometer, you must include the conversion factor.

And whatever units you use, if they are consistent  (all SI, or all FPS.....) between torque and moment of inertia, the result of applying a constant torque to a freely rotating body is always rad/sec². That's all you need to teach and learn.

 

In 1993 the American Association of Physics Teachers Metric Committee specified that the radian should explicitly appear in quantities only when different numerical values would be obtained when other angle measures were used,

Now suppose you want to calculate α in grad/sec², or rpm/sec.  This means you will have to define Hamdani torque as something other than just force x distance, depending on what units you want to use for angle. But you exert and measure torque by just hanging a weight on a bar.....

[hamdani yusuf (OP)]

And whatever units you use, if they are consistent  (all SI, or all FPS.....) between torque and moment of inertia, the result of applying a constant torque to a freely rotating body is always rad/sec2. That's all you need to teach and learn.

Not necessarily. It can be any unit of rotational angle divided by time squared. It can be turn per minute squared.

[alancalverd]

But if you use consistent imperial units, foot-pounds and lbm.ft², or consistent SI units N.m and kg.m², α is automatically in rad/sec², just as you were taught in school.

In the absence of a problem, why invoke a "solution" that only applies to free rotation?