
#1
Jan1713, 12:20 PM

P: 31

When an object move in space, what decides where it moves to? For instance there's no rule saying you can't move from 0 to 3, but have to move from 0 to 1 simply because 1 is next to 0 in terms of distance.




#2
Jan1713, 12:28 PM

C. Spirit
Sci Advisor
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P: 4,915

I'm not entirely sure what your question is but I believe what you are asking about is the principle of stationary action: http://en.wikipedia.org/wiki/Principle_of_least_action




#3
Jan1713, 12:58 PM

P: 31

I'm looking more for a science proof has to do with the particle movement. The smallest distance is known as Planck Length as someone mentioned. (http://en.wikipedia.org/wiki/Planck_length) So if you move through Planck Length from point A to point B, what decides where you show up when you hit point B, because with Planck Length being the smallest distance it seems like you've skipped this distance and ended up in a new place. Does movement of any length and size comes down to this as a minimum?




#4
Jan1813, 04:56 AM

Sci Advisor
PF Gold
P: 11,341

Question about movement 



#5
Jan1813, 05:31 AM

P: 1,197

There are no "proofs"; the physical interpretation of the Planck length still seems to depend on what theory you subscribe to. But I think it is important to note that under a common interpretation, it is defined as the shortest "measurable" length, not the shortest length.




#6
Jan1813, 07:46 AM

P: 2,861

I'm no expert on this but...
It sounds like the OP is assuming particles can only occupy positions that are on a plank scale grid. Are there theories that suggest this might be the case? 



#7
Jan1813, 09:00 AM

P: 70

As for the second part of this question I'm not sure what you mean by selecting arbitrary numbers and saying there is no rule against moving from one to the other. If you are using them as a measure of displacement from a starting point, in meters say, then there is a general rule that you have to move 1, 2 meters before you can have moved 3, unless you found a suitable method of teleportation. Have I misunderstood the question? * http://en.wikipedia.org/wiki/Kinetic_energy 



#8
Jan1813, 09:17 AM

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P: 11,341

Whatever the answer is to the above, I think that Space must be assumed to be monotonic  at least when considering three dimensional space. But when the multidimensional space of String Theory is brought into it, this may not be right. 



#9
Jan1813, 09:24 AM

P: 158

Or are you referring to the discrete nature of energies and confusing this with the inability of a particle to stay at a location with not being able to move through it?
Let's say there is some minimum movement for a particle based on a discrete energy that causes it to move some distance from A to B, as it's semi stable able to occupy those locations space. That does not indicate that it did not pass through an infinite number of possible locations in between. My interpretation from quantum mechanics is that there are a number of discrete locations that could be inhabited by a particle but I believe this is the nature of the particle not the nature of space and motion itself. Although if someone wouldn't mind explaining the physical path followed by a particle during tunneling. 



#10
Jan1813, 09:26 AM

P: 31

I understand the object is supposed to move in the direction of the applied force, I'm just not sure how the object ends up at that position after the displacement. To me it seems like every movement made is going through multiples of Planck Length, and since movement is possible, there must be a smooth transition for an object to travel from one location to the next. Like something is telling you, after you move away from point A, you will end up in point B. I guess my question would be what goes on between Planck Length that displaces you to the next position.




#11
Jan1813, 09:29 AM

Mentor
P: 28,783

Zz. 



#12
Jan1813, 09:49 AM

P: 10

When a paritlce moves from A > B is its motion broken into finitely many small jumps as I think the OP is suggesting, or is the motion more accurately described as a smooth transition with no possible way to break it down into steps?
Is there/Has there been a way to prove this theoretically one way or another? 



#13
Jan1813, 09:53 AM

P: 10

Maybe it's easier to think of a probability density instead of a point particle. So then you can invision a continuous smooth shift in the most likely place for the particle to exist, because I guess you can assign an infinite number of points in space with a probability function.




#14
Jan1913, 05:48 AM

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P: 3,337





#15
Jan1913, 11:23 AM

P: 79

BTW you may be interested in reading up on Zeno's paradox.... 



#16
Jan2113, 02:01 PM

P: 31

After some thought, I think force decides the direction the object is supposed to travel, but not the destination. Since force remain constant at all places, but the place you travel to is different. So does that mean the space you're in uses force to find the destination you travel to? And does bending space generate a force in return. Just some thought, hopefully I'm not off topic.




#17
Jan2113, 10:32 PM

HW Helper
P: 3,337

yeah, and no. I would agree with some of the stuff you're saying. (Talking about nonquantum physics now). Force is the instantaneous rate of change of momentum, so the force tells us how the motion is changing in that instant. I don't understand what you mean by "Since force remain constant at all places, but the place you travel to is different." Do you mean that if the force is constant, then the place you travel to can still be different? This is because force only tells us the second differential of position, so if we know the constant force, then there are still two (vector) unknowns, which correspond to initial position and initial velocity.




#18
Jan2313, 06:59 AM

P: 31

What you said is correct, I'm just wondering where the information of the destination is held. The idea about moving object with force is credited to BenG549 and the direction is through someone I met online. I think I'll stop here. There might be more questions in the future.



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