What happens at the exact center?
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What happens at the exact center?
Say we have a record player with a record spindle. You can play a 12-inch record on it by putting the spindle through the hole at the center of the record. The record, with the spindle, then rotates at a certain speed when the record plays.
Say you're five inches from the center. Then that point moves around the center at a certain speed. Now say you're four inches from the center. Then that point moves slower around the center. Three inches, two inches, one inch, it moves slower and slower. On the spindle the selected point moves slower still until you reach the exact center where at that point, the spindle isn't moving at all!
If you don't believe it, test it out. It also proves you can have a dimensionless point in physical space.
There's a certain similarity between this example and the eye of the hurricane.
PhilX
Say you're five inches from the center. Then that point moves around the center at a certain speed. Now say you're four inches from the center. Then that point moves slower around the center. Three inches, two inches, one inch, it moves slower and slower. On the spindle the selected point moves slower still until you reach the exact center where at that point, the spindle isn't moving at all!
If you don't believe it, test it out. It also proves you can have a dimensionless point in physical space.
There's a certain similarity between this example and the eye of the hurricane.
PhilX
Re: What happens at the exact center?
The center point might not be moving relative to the rest of the record but it is still rotating which is a kind of movement. How do you define movement, is it always changing your location in space, or can it be just changing your orientation in the same location?Philosophy Explorer wrote: โThu May 17, 2018 11:01 am Say we have a record player with a record spindle. You can play a 12-inch record on it by putting the spindle through the hole at the center of the record. The record, with the spindle, then rotates at a certain speed when the record plays.
Say you're five inches from the center. Then that point moves around the center at a certain speed. Now say you're four inches from the center. Then that point moves slower around the center. Three inches, two inches, one inch, it moves slower and slower. On the spindle the selected point moves slower still until you reach the exact center where at that point, the spindle isn't moving at all!
If you don't believe it, test it out. It also proves you can have a dimensionless point in physical space.
There's a certain similarity between this example and the eye of the hurricane.
PhilX
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Re: What happens at the exact center?
Why do you say the exact center point is rotating? Movement means changing your location over timethedoc wrote: โThu May 17, 2018 1:52 pmThe center point might not be moving relative to the rest of the record but it is still rotating which is a kind of movement. How do you define movement, is it always changing your location in space, or can it be just changing your orientation in the same location?Philosophy Explorer wrote: โThu May 17, 2018 11:01 am Say we have a record player with a record spindle. You can play a 12-inch record on it by putting the spindle through the hole at the center of the record. The record, with the spindle, then rotates at a certain speed when the record plays.
Say you're five inches from the center. Then that point moves around the center at a certain speed. Now say you're four inches from the center. Then that point moves slower around the center. Three inches, two inches, one inch, it moves slower and slower. On the spindle the selected point moves slower still until you reach the exact center where at that point, the spindle isn't moving at all!
If you don't believe it, test it out. It also proves you can have a dimensionless point in physical space.
There's a certain similarity between this example and the eye of the hurricane.
PhilX
(r x t = d). Since I contend the exact center isn't moving, then its orientation remains the same.
PhilX
Re: What happens at the exact center?
In theory, considering all centers extend from further centers, a unified pure "center" or 1 dimensional existence would be infinite movement as no-movement.
Re: What happens at the exact center?
Mathematically speaking, there is no orientation of a point. It (or an axis actually) cannot 'face' another way without linear movement. It necessarily has zero angular momentum and cannot be said to be moving.
The center indeed does not move, but it has no orientation to remain the same. If it did, it would be moving.Philosophy Explorer wrote: โThu May 17, 2018 2:02 pmSince I contend the exact center isn't moving, then its orientation remains the same.
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In physics, there is nothing at the axis, so all the matter is moving relative to the axis, but not uniformly since the temperature is not zero. It's the average that counts.
In physics, there is no such thing as a axis that is not accelerating in some way. More formally, I can think of no examples of a thing (even an abstract one like the center of gravity of the solar system) whose first three derivatives are all zero, in any reference frame.
Re: What happens at the exact center?
Noax wrote: โThu May 17, 2018 5:13 pmMathematically speaking, there is no orientation of a point. It (or an axis actually) cannot 'face' another way without linear movement. It necessarily has zero angular momentum and cannot be said to be moving.
The 0d point and 1d line are axioms of mathematics that are justified by the corresponding arguments which extend from them. What if the axiom of the 0d point was inverted to a 1d structure directed into itself ad-infinitum so no separation occurs?
The center indeed does not move, but it has no orientation to remain the same. If it did, it would be moving.Philosophy Explorer wrote: โThu May 17, 2018 2:02 pmSince I contend the exact center isn't moving, then its orientation remains the same.
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In physics, there is nothing at the axis, so all the matter is moving relative to the axis, but not uniformly since the temperature is not zero. It's the average that counts.
In physics, there is no such thing as a axis that is not accelerating in some way. More formally, I can think of no examples of a thing (even an abstract one like the center of gravity of the solar system) whose first three derivatives are all zero, in any reference frame.
Re: What happens at the exact center?
Interesting philosophical discussion but unfortunately it has nothing to do with reality and practical matters.
Re: What happens at the exact center?
That was not very practical for you to state that... Where the metaphysics which inevitably led to the scientific method not practical if they led to what was practical?
Re: What happens at the exact center?
Scientific discoveries are made by those who look at the way the world is, not by those who imagine how they would like it to be.
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Re: What happens at the exact center?
When I made my discoveries in the field of sales, I did it through years of testing and experimentation with the observation and keeping meaningful records that was required. And yet I say I barely scratched the surface as more discoveries may await others. In my case, after some failures, serendipity found me and set me on the right paths (because serendipity found me twice and I have the ability to analyze). In my case doc, you also need to imagine how you would like things to be (but be honest about it) so that you know what you're shooting for (in my case, it was to know that I could improve upon my sales rate and I did).thedoc wrote: โSun May 20, 2018 4:02 amScientific discoveries are made by those who look at the way the world is, not by those who imagine how they would like it to be.
I say it's okay to dream and imagine, but you must work at it to achieve as I've done for myself and others. So to sum, you need both.
PhilX
Re: What happens at the exact center?
I should have been more clear, I was referring to imagining about some never achievable fantasy world. Imagining about changing the real world is OK, and from what I have seen you have based all your speculation on real world situations.Philosophy Explorer wrote: โSun May 20, 2018 4:33 amWhen I made my discoveries in the field of sales, I did it through years of testing and experimentation with the observation and keeping meaningful records that was required. And yet I say I barely scratched the surface as more discoveries may await others. In my case, after some failures, serendipity found me and set me on the right paths (because serendipity found me twice and I have the ability to analyze). In my case doc, you also need to imagine how you would like things to be (but be honest about it) so that you know what you're shooting for (in my case, it was to know that I could improve upon my sales rate and I did).
I say it's okay to dream and imagine, but you must work at it to achieve as I've done for myself and others. So to sum, you need both.
PhilX
Re: What happens at the exact center?
There is an equation for this,
w:angular speed
t: time
ฮธ: angular displacement
r: distance from center of rotation
v: linear speed
w= dฮธ/dt = v/r
v=wr
For a record that is rotating at constant angular speed, the linear speed of a point on the record is proportional to the distance from the center, I.e. r. Since at the center r=0, the mathematics says that it must be stationary!
w:angular speed
t: time
ฮธ: angular displacement
r: distance from center of rotation
v: linear speed
w= dฮธ/dt = v/r
v=wr
For a record that is rotating at constant angular speed, the linear speed of a point on the record is proportional to the distance from the center, I.e. r. Since at the center r=0, the mathematics says that it must be stationary!
Re: What happens at the exact center?
The center point is changing it's orientation 360 degrees with each rotation of the record. Are you saying that changing the direction each rotation is not a movement?Philosophy Explorer wrote: โThu May 17, 2018 2:02 pmWhy do you say the exact center point is rotating? Movement means changing your location over timethedoc wrote: โThu May 17, 2018 1:52 pm
The center point might not be moving relative to the rest of the record but it is still rotating which is a kind of movement. How do you define movement, is it always changing your location in space, or can it be just changing your orientation in the same location?
(r x t = d). Since I contend the exact center isn't moving, then its orientation remains the same.
PhilX
Re: What happens at the exact center?
The equations by Averroes are correct, and they say there is no orientation of the center point.
w= dฮธ/dt = v/r
v/r = 0/0, an undefined meaningless value. Orientation is undefined if rotation is undefined (the latter being a change of orientation). The term concerns only points not at the center.
So yes, we're saying that there is no movement of the center axis during the rotation of the remainder of the object.
Again, this is a mathematical description that has little to do with reality. Physical mass doesn't have a location to be at the center axis, and certainly would not rotate in place if it did. But an elementary particle (something not a collection of smaller things) has no orientation. It is not something that can be meaningfully expressed or measured.
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Re: What happens at the exact center?
As I said, the closer you get to the center of the record or spindle, the slower either one moves which you can test out for yourself doc. This means there is no movement at the center which also means the center doesn't rotate and we have a paradox since the rest of the record and spindle moves (however fast they move).thedoc wrote: โSun May 20, 2018 10:37 pmThe center point is changing it's orientation 360 degrees with each rotation of the record. Are you saying that changing the direction each rotation is not a movement?Philosophy Explorer wrote: โThu May 17, 2018 2:02 pmWhy do you say the exact center point is rotating? Movement means changing your location over timethedoc wrote: โThu May 17, 2018 1:52 pm
The center point might not be moving relative to the rest of the record but it is still rotating which is a kind of movement. How do you define movement, is it always changing your location in space, or can it be just changing your orientation in the same location?
(r x t = d). Since I contend the exact center isn't moving, then its orientation remains the same.
PhilX
PhilX