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Re:Mass and angular momentum, left ambiguous by Einstein, ge... by hinkley on Friday July 15, 2022 @02:52PM (#32111543)
Maybe a year ago, possibly here, I finally saw gyroscopic precession demonstrated in a way that didn’t invoke magic thinking. The person simply pointed out that the mistake is in thinking of the rotating mass as a stationary object, when in fact you are applying the lateral force to a different spot on the object at each time interval, leading to very strange vectors.
Re:Mass and angular momentum, left ambiguous by Einstein, ge... by ridiculous_fish on Friday July 15, 2022 @08:37PM (#32114246)
Here's an insight that helped me: gyroscopic precession is the rotational analog of a circular orbit.

A circular orbit is when a linear force is applied orthogonal to linear velocity. The direction changes, but not magnitude (speed).

Gyroscopic precession is when a rotational force (torque) is applied orthogonal to rotational velocity. The axis of rotation changes but not magnitude (rotational speed).

Re:Mass and angular momentum, left ambiguous by Einstein, ge... by polishdude20 on Friday July 15, 2022 @03:47PM (#32112026)
Is there a link to a resource on this or was it just in person? I'd love to hear the intuition you describe!
Re:Mass and angular momentum, left ambiguous by Einstein, ge... by aliraheem on Friday July 15, 2022 @04:59PM (#32112755)
Here it is https://science.howstuffworks.com/gyroscope.htm#pt2

I've never thought much of it.

Re:Mass and angular momentum, left ambiguous by Einstein, ge... by leephillips on Friday July 15, 2022 @05:59PM (#32113238)
The misleading and faulty explanation in this link talks about the “desire” of a point on the wheel to move in a certain direction. Now that’s some magical thinking.
Re:Mass and angular momentum, left ambiguous by Einstein, ge... by gumby on Friday July 15, 2022 @08:16PM (#32114116)
You might want to read “The Intentional Stance” by Daniel Dennett, a philosophical treatise basically on how we usefully ascribe desire or intention to inanimate objects and phenomena as a mental model (for example, saying that “The thermostat tries to keep the temperature between 20 and 30”).

(This is not a comment on the precession video itself, which haven’t clicked on)

Re:Mass and angular momentum, left ambiguous by Einstein, ge... by leephillips on Friday July 15, 2022 @08:20PM (#32114135)
I’m well aware of this manner of speaking. Everyone is. If you did look at what I was commenting on (not a video) you might agree that its use in that case doesn’t help, at all. Or not.

I’ll look up the Dennett article, thanks.

Re:Mass and angular momentum, left ambiguous by Einstein, ge... by lucideer on Friday July 15, 2022 @09:15PM (#32114449)
I haven't read the Dennett article but in this specific context, "desire" just seems like a simple proxy for momentum. What am I missing?
Re:Mass and angular momentum, left ambiguous by Einstein, ge... by aliraheem on Saturday July 16, 2022 @02:37PM (#32120671)
I agree.

I don't see how this is not magical thinking but the rules of arithmetic are.

Re:Mass and angular momentum, left ambiguous by Einstein, ge... by roflyear on Friday July 15, 2022 @10:57PM (#32114870)
What an awful site on mobile.
Re:Mass and angular momentum, left ambiguous by Einstein, ge... by xhrpost on Saturday July 16, 2022 @12:28AM (#32115230)
Hmm, can this explanation work in reverse? I've always found the conservation of momentum to be very confusing. Why does a spinning body cause an orthogonal rotation upon itself and thus any rigid body it's attached to? I know there's math to explain it, but it just doesn't seem intuitive to understand.
Re:Mass and angular momentum, left ambiguous by Einstein, ge... by leephillips on Friday July 15, 2022 @05:46PM (#32113159)
Does this have something to do with the article?

I don’t recall any “magic thinking” in the explanation of precession in my introductory undergraduate physics text. Just Newton’s laws and vector cross-products.

“you are applying the lateral force to a different spot on the object at each time interval” : how is that applied when the force is gravity, applied to every point of the object at every time?

Re:Mass and angular momentum, left ambiguous by Einstein, ge... by lucideer on Friday July 15, 2022 @09:11PM (#32114424)
> how is that applied when the force is gravity, applied to every point of the object at every time?

It's about the point of suspension resisting gravity. The axis is "held" at a point, applying an "upward" force (resisting gravity). With gravity as you say evenly acting, the point opposite that through the centre of gravity will have a downward vector. The natural result of these opposing vectors might be rotation through the centre of gravity, but when those rotational forces are applied to moving targets you get suspension from the product.