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The perfect circle or sphere.

LuxFerum

Philosopher
L
Joined
Dec 19, 2002
Messages
5,390
Is there something in this universe that is perfectly round?
I think that the event horizon of a black hole is a perfect sphere, but I'm not sure.
Maybe some sub-atomic particle could be classified as a perfect sphere.
What do you think?
 
LuxFerum said:
Is there something in this universe that is perfectly round?
Click to expand...
Possibly, but we have no way of finding out. To be able to prove something was perfectly round we would require measurement instruments that have infinite precision, since we're talking about continuous variables here.
 
Re: Re: The perfect circle or sphere.

Iconoclast said:
Possibly, but we have no way of finding out. To be able to prove something was perfectly round we would require measurement instruments that have infinite precision, since we're talking about continuous variables here.
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Not really, we can prove it by showing that if is not perfectly round, it would lead to absurd conclusions.
 
Re: Re: Re: Re: The perfect circle or sphere.

Diogenes said:



What are you saying?


Iconoclast's, observation seems to satisfy your question..
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What Im saying, is that we don't need to have infinite precision.

There is a limit in the universe on how precise you can be.

If you want to be more precise than that, the particule that you are using will have an amount of energie so big that will create a black hole.

Therefore there is nothing below that level.
 
LuxFerum said:

I think that the event horizon of a black hole is a perfect sphere, but I'm not sure.
Click to expand...
Not if it is spinning.

How 'bout a water blob in deep outerspace. Would it become a perfect sphere given enough time? (Actually I don't now how you would keep it liquid.)

Walt
 
Re: Re: Re: Re: Re: The perfect circle or sphere.

LuxFerum said:

What Im saying, is that we don't need to have infinite precision.

There is a limit in the universe on how precise you can be.
Click to expand...

Well, you probable threw them off by starting the thread with the word PERFECT.

;)
 
Re: Re: Re: Re: Re: The perfect circle or sphere.

LuxFerum said:
There is a limit in the universe on how precise you can be.
Click to expand...
Well that answers your question doesn't it. I'd not thought of the problem of Plank length, but obviously that precludes any possibility of a perfect circle existing anywhere regardless of the fact that we couldn't verify it even if it did exist.

Or.... when you said "perfect" did you mean to use the oxymoronic term "perfect enough"?
 
Lux,

The answer is "no".
Sooner or later, as you zero in, it's going to get grainy.

BJ
 
Re: Re: Re: Re: Re: Re: The perfect circle or sphere.

Iconoclast said:

Well that answers your question doesn't it. I'd not thought of the problem of Plank length, but obviously that precludes any possibility of a perfect circle existing anywhere regardless of the fact that we couldn't verify it even if it did exist.

Or.... when you said "perfect" did you mean to use the oxymoronic term "perfect enough"?
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Hell not, if is nothing below that point, there is no sense in say that some irregularity will show up.
 
Re: Re: Re: Re: Re: Re: The perfect circle or sphere.

Jim_MDP said:


Well, you probable threw them off by starting the thread with the word PERFECT.

;)
Click to expand...
By perfect I mean

Fulfilling exactly the definition.
 
BillyJoe said:
Lux,

The answer is "no".
Sooner or later, as you zero in, it's going to get grainy.

BJ
Click to expand...
There is no way something can get grainy if you are using the smalest grain possible.
 
Re: Re: Re: Re: Re: Re: Re: The perfect circle or sphere.

LuxFerum said:
By perfect I mean

Fulfilling exactly the definition.
Click to expand...
Well this is going round in circles.

Are you going to actually tell us your definition of a perfect circle or should we just keep guessing until you tell us to stop?

The mathematical DEFINITION of a perfect circle is one with (exactly) constant radius, and we've shown that a perfect circle can't exist. You do realise that a "circle" exists only in the realm of mathematics don't you? What we call a circle or a sphere in the world of reality is just some imperfect approximation to the mathematically ideal circle. Same goes for a line, a point, a dodecahedron.

How about this: "Is it possible in the real world for a circle or sphere to exist that has a radius that never varies from the mathematical model by more than 1 plank length?"

Assuming that's your question, then the answer is... most probably not. Using (say) a soap bubble as an example, you have to take into account the gravity of every other object in the universe close enough or massive enough to impart a distortion in the surface of the sphere of greater than 0.5 plank length -- or more correclty -- you need to find an area of space that is at all points euclidian to within that distance, an exercise I leave up to the reader.
 
Re: Re: Re: Re: Re: Re: Re: Re: The perfect circle or sphere.

Iconoclast said:
How about this: "Is it possible in the real world for a circle or sphere to exist that has a radius that never varies from the mathematical model by more than 1 plank length?"

Assuming that's your question, then the answer is... most probably not.
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Ah, but what if the circle/sphere is 1 planck length in radius? :D
 
Re: Re: Re: Re: Re: Re: Re: Re: Re: The perfect circle or sphere.

Cecil said:
Ah, but what if the circle/sphere is 1 planck length in radius? :D
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Well how are you gonna see it smart guy!!!! :D;)
 
Re: Re: Re: Re: Re: Re: Re: Re: The perfect circle or sphere.

Iconoclast said:

How about this: "Is it possible in the real world for a circle or sphere to exist that has a radius that never varies from the mathematical model by more than 1 plank length?"
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There is no variation below that level.
To assume that could be a variation below that level but we will never know don't make any sense, it is useless.


Iconoclast said:

Assuming that's your question, then the answer is... most probably not. Using (say) a soap bubble as an example, you have to take into account the gravity of every other object in the universe close enough or massive enough to impart a distortion in the surface of the sphere of greater than 0.5 plank length -- or more correclty -- you need to find an area of space that is at all points euclidian to within that distance, an exercise I leave up to the reader.
Click to expand...
It could be a particle so small that the gravity will not make a distortion between the point where the particle begins to the point where it ends.
Or it could be so big that his distortion of his surrounding leads to a black hole where the is impossible to make the distortion bigger.


What about equipotential sufaces? In a point of the universe where the distortion is irrelevant, this should be perfectly round.
especialy because is not matter is a force.
 
Re: Re: Re: Re: Re: Re: Re: Re: Re: The perfect circle or sphere.

LuxFerum said:
There is no variation below that level.
To assume that could be a variation below that level but we will never know don't make any sense, it is useless.
Click to expand...
You spin me right round, baby
Right round like a record, baby
Right round round round
You spin me right round, baby
Right round like a record, baby
Right round round round
You spin me right round, baby
Right round like a record, baby
Right round round round
You spin me right round, baby
Right round like a record, baby
Right round round round
You spin me right round, baby
Right round like a record, baby
Right round round round

(now everybody!)

You spin me right round, baby
Right round like a record, baby
Right round round round


I think this conversation's over.
 
Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: The perfect circle or sphere.

Iconoclast said:

(now everybody!)
You spin me right round, baby
Right round like a record, baby
Right round round round
I think this conversation's over.
Click to expand...
What the hell are you talking about?:confused:
Use the Occam's razor. There is no point in assuming something indetectable.


Someone here understand what I'm saying or I'm really gone insane. :confused:
 
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