'New' type of angle measurement to often replace radians

Click For Summary

Discussion Overview

The discussion revolves around the proposal of a new type of angle measurement that could potentially replace radians in certain contexts, particularly in applications like raytracing. Participants explore the implications of defining angles as fractions of a circle, such as using unity to represent a quarter circle as 0.25, and the practicality of this approach compared to traditional measurements like radians and degrees.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants suggest that defining angles as fractions of a circle (e.g., 0.25 for a quarter circle) could simplify calculations in certain projects, like raytracing.
  • Others argue that this approach may lead to the loss of important calculus results that are valid only when angles are measured in radians.
  • There is a comparison made to "grads," which are used in engineering, where 1 grad equals a right angle, and participants discuss the relationship between this and the proposed new measurement system.
  • Some participants note that while the idea of using revolutions or cycles as angle measurements is not new, it is not commonly implemented in calculators for trigonometric functions.
  • One participant expresses uncertainty about fully replacing radians but sees value in using the new system alongside existing ones.
  • Another participant shares anecdotal experiences from their work, mentioning the use of revolutions in practical applications, suggesting that this method has been encountered in real-world scenarios.

Areas of Agreement / Disagreement

Participants express a mix of opinions, with some supporting the idea of a new measurement system while others emphasize the importance of radians for calculus and traditional applications. The discussion remains unresolved, with multiple competing views on the utility and implications of the proposed angle measurement.

Contextual Notes

Participants highlight limitations in the current use of angle measurements in calculators and the potential for confusion regarding the definitions of "grads" and the proposed new measure. There are also references to specific applications where different angle measurements might be more practical, but these are not universally accepted.

Twinbee
Messages
116
Reaction score
0
Maybe I'm biased because of the kind of projects I'm pursuing (raytracing), but I can't help feeling that for many areas, instead of defining a circle in terms of radians (or degrees for that matter), we should simply use unity and define say, a quarter of a circle as being 0.25.

Obviously a radian has the same length as the radius of a given circle, and I understand that radians have their place (for example, angular velocity in physics), and can help to reduce the number of unnecessary factors. But for other projects, defining angles from zero to one can also help reduce the factors.

Because of the above I'm ending up defining my own trig commands, e.g.:
MySin(0.125) = 0.7071... (1/8th of a circle)
MySin(0.25) = 1... (1/4th of a circle)
etc.

Has anyone else found this could be useful or is it just me?
 
Last edited:
Mathematics news on Phys.org
You lose all the nice calculus results like this
 
It's not that far from "grads", used by engineers building roads, etc. where 1 grad is a right angle. 4 of your measures = 1 grad= 90 degrees= pi/2 radian.

However, as Office Shredder says, calculus formulas like d(sin(x))/dx= cos(x), d(cos(x))/dx= - sin(x), \int sin(x)dx= -cos(x)+ C, \int cos(x) dx= sin(x)+ C are only true for x measured in radians.
 
HallsofIvy said:
It's not that far from "grads", used by engineers building roads, etc. where 1 grad is a right angle. 4 of your measures = 1 grad= 90 degrees= pi/2 radian.

I thought a grad was 1/400th of a circle
 
This is not a new idea, many people do use a complete revolution as the unit of an angle. Do you know what "rpm" and "Hz" stand for?
 
@Redbelly98: Yes, but I never see any calculators use 'revs' or 'cycles' in addition to degrees or radians, for use in trigonometric functions. That seems pretty strange because as you said, they're used everywhere. So I need to define the functions separately (which the excellent CCalc (console calculator) for example allows one to do thankfully).

Just to clarify, I'm certainly not advocating that we completely replace radians (for the reasons given in the above posts). I'm on the fence about using 'my' system as default, but my bias could certainly be affecting that particular judgment. I just think that using it in addition to the other two popular systems would be very useful.

Again, is there anyone other than me who would find revs instead of radians more useful for their everyday math/sciency stuff?
 
Last edited:
Office_Shredder said:
I thought a grad was 1/400th of a circle
You are right- I mispoke. There are 100 grads to a right angle. That way engineers can think of grades as "percentages".

What I should have said was "4 of your measures = 100 grads= 90 degrees= pi/2 radian." so that 1 of this "new measure" is 25 grads= 22.5 degrees= \pi/8 radians.
 
Twinbee said:
@Redbelly98: Yes, but I never see any calculators use 'revs' or 'cycles' in addition to degrees or radians, for use in trigonometric functions. That seems pretty strange because as you said, they're used everywhere. So I need to define the functions separately (which the excellent CCalc (console calculator) for example allows one to do thankfully).

Just to clarify, I'm certainly not advocating that we completely replace radians (for the reasons given in the above posts). I'm on the fence about using 'my' system as default, but my bias could certainly be affecting that particular judgment. I just think that using it in addition to the other two popular systems would be very useful.

Again, is there anyone other than me who would find revs instead of radians more useful for their everyday math/sciency stuff?
Wave frequency is typically given in terms of "Herz" and, of course, automotive engineers and mechanics often use "rpm".
 
And then there was the advice my thesis advisor gave me, "When you open up a valve in a vacuum system all the way, be sure to back it off a quarter of a turn so that the threads don't seize up over time."

We also would refer to motions of adjustment screws as "2 turns", "half a turn", etc.

EDIT: I vaguely remember, while I was working out numerical solutions to a DC motor's motion a couple of years ago, that I was using revolutions. But that might have been simply a conversion of the output, after letting the code work things out in radians first.
 
Last edited:

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 1 ·
Replies
1
Views
8K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 35 ·
2
Replies
35
Views
11K
Replies
24
Views
8K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K