1
   

Does the Arrow Move?

 
 
tcis
 
Reply Thu 1 Jul, 2004 06:42 pm
How can an arrow move toward a target? Does an arrow move?

"The ancient Greek philosopher Zeno approached the problem of space through the question of movement in space. Before the moving body can reach the point of its destination it must pass through half the space intervening between the point of start and the point of destination; and before it can pass through that half it must travel through the half of the half, and so on to infinity. We cannot move from one point of space to another without passing through an infinite number of points in the intervening space. But it is impossible to pass through an infinity of points in a finite time. He further argued that the flying arrow does not move, because at any time during the course of its flight it is at rest in some point of space. Thus Zeno held that movement is only a deceptive appearance and that Reality is one and immutable. The unreality of movement means the unreality of an independent space."
  • Topic Stats
  • Top Replies
  • Link to this Topic
Type: Discussion • Score: 1 • Views: 2,254 • Replies: 28
No top replies

 
extra medium
 
  1  
Reply Thu 1 Jul, 2004 06:57 pm
The problem is solved by some by assuming that space IS NOT infinitely divisible. A bit ironically, this is how Islamic philosophers solved it a few hundred years ago. Modern math, though, has indicated that space is indeed infinitely divisible. So the debate continues.
0 Replies
 
fortune
 
  1  
Reply Thu 1 Jul, 2004 07:10 pm
Too many points, not enough movement. Is movement the measurement of the distance between to places or of the time it takes to traverse that distance?
0 Replies
 
JLNobody
 
  1  
Reply Fri 2 Jul, 2004 12:02 am
It only points out the artificiality of logic. All I know is that I do not ever stand in the way of a flying arrow.
0 Replies
 
Solon
 
  1  
Reply Sat 3 Jul, 2004 12:07 pm
We are standing still and the universe moves around us. Besides, all you have to do is break time down the same way; into infinite points.
0 Replies
 
fortune
 
  1  
Reply Sat 3 Jul, 2004 12:13 pm
Yeah, but if there are infinite points then how is it that we ever get to the end of them?
0 Replies
 
carditel
 
  1  
Reply Sat 3 Jul, 2004 03:19 pm
If someone jumps into the air he exists in only two states - touching the ground or not touching the ground. The action of leaving the ground does not seem to exist. Confused
0 Replies
 
fortune
 
  1  
Reply Sun 4 Jul, 2004 07:35 am
How could space be infinitely divisible? One could measure the distance between two points, but in order to even HAVE points the points themselves must have a diameter, which means in the end you would reach a time when the two points, between which you are measuring, will meet. Wouldn't you?


Never mind this post. I wrote it when i was very tired and not really paying attention.
0 Replies
 
Rick d Israeli
 
  1  
Reply Sun 4 Jul, 2004 03:20 pm
It moves.
0 Replies
 
fresco
 
  1  
Reply Sun 4 Jul, 2004 03:46 pm
Cantor, the mathematician, went insane contemplating "different types of infinity." !

The Zeno problem does however raise the interesting issue of the relationship between a formal mathematical model and "reality". As JLN points out, even "logic" is merely a model which can only be applied selectively.
0 Replies
 
akaMechsmith
 
  1  
Reply Sun 4 Jul, 2004 04:11 pm
JL, I have frequently come across similar little abuses of common sense in some of the "scientific" threads.

To wit; Most recently in a discussion of "black holes" I remarked that there are always limits to the amount of energies (and or matter, interchangeable in this case) that a given object can absorb without seriously changing its characteristics.

For instance a flywheel- Add enough speed or heat you will no longer have a flywheel. You will have something but it won't be a flywheel.

Add enough energy to a black hole you will no longer have a black hole. You will have something but it won't be a "black hole". Personally I suspect it would be called a galaxy Confused

So to me it's clear, The infinite number of points in the path of the arrow is simply a mathematical construction that probably has no counterpart in an observable (and possibly real) Universe.

Occasionally the physicists are as amusing as the preachers Crying or Very sad
0 Replies
 
thethinkfactory
 
  1  
Reply Sun 4 Jul, 2004 05:33 pm
I have been reading about M-theory of Space and time. Space and time - acording to this theory - are atomistic and therefore made of decrete units.

If this were true then there is not an infinite amount of time for the arrow to move nor an infinite amount of space. There would be a finite (although large) amount of descrete units of time and space for the arrow to move in.

The smallest unit according to this thoery is the same length as the Planck era or 10-42 seconds.

TF
0 Replies
 
satt fs
 
  1  
Reply Sun 4 Jul, 2004 05:47 pm
Discrete time may be an answer.

However even with a continous time:
An attempt is sometimes easier than expected.
(.. Or, fear often exaggerates danger.)
0 Replies
 
JLNobody
 
  1  
Reply Sun 4 Jul, 2004 10:44 pm
I once read that Buddhist theory, whatever that means, holds a notion of time as consisting of discrete units. I don't know which branch or sect of Buddhism that is, but it rings no bells for me.
0 Replies
 
Solon
 
  1  
Reply Sun 4 Jul, 2004 11:14 pm
If you can assume that time can be cut down into infinite chunks, then you can just as easily assume that it can't be.
0 Replies
 
thethinkfactory
 
  1  
Reply Mon 5 Jul, 2004 04:06 pm
Solon,

How could a person cut down time into infinite chunks?

If you mean cutting it down into finite chunks - of course you can assume it need not be so. This simply means that discrete time and non-discrete time are not contradictory.

JLN:

Those dang Buddhists - they are smart for being so skinny... Wink

TF
0 Replies
 
Solon
 
  1  
Reply Mon 5 Jul, 2004 07:54 pm
Discrete time isn't the answer to this problem in particular. Just assume the universe is moving around the arrow (in space&time), so the arrow doesn't move.
0 Replies
 
JLNobody
 
  1  
Reply Mon 5 Jul, 2004 08:25 pm
This debate reminds me of one between to zen monks. One held that when the flag flaps in the breeze, the air is moving the flag. The other argued that the flag is moving the air around it. Just then their teacher came along, and they asked him to artibrate. He told them that if they looked closely they would see that it is their minds that were doing the flapping. Laughing
0 Replies
 
john-nyc
 
  1  
Reply Mon 5 Jul, 2004 09:13 pm
How long is the arrow?
0 Replies
 
JLNobody
 
  1  
Reply Mon 5 Jul, 2004 09:23 pm
From which end?
0 Replies
 
 

Related Topics

How can we be sure? - Discussion by Raishu-tensho
Proof of nonexistence of free will - Discussion by litewave
Destroy My Belief System, Please! - Discussion by Thomas
Star Wars in Philosophy. - Discussion by Logicus
Existence of Everything. - Discussion by Logicus
Is it better to be feared or loved? - Discussion by Black King
Paradigm shifts - Question by Cyracuz
 
  1. Forums
  2. » Does the Arrow Move?
Copyright © 2024 MadLab, LLC :: Terms of Service :: Privacy Policy :: Page generated in 0.03 seconds on 04/26/2024 at 03:33:34