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Post by Evilduck on Nov 9, 2006 0:27:09 GMT -5
Jeff's post about .999... reminded me of Zeno's paradox, which goes as follows:
Motion does not exist. For an arrow to reach it's target, first it must cover half the distance, then a quarter, then an eighth, then a sixteenth of the distance and so on. If the interval between arrow and target is halved each time, the arrow will never reach the target.
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Post by caffine10x on Nov 9, 2006 2:41:35 GMT -5
its sorta true. I remember someone said that when you push your finger into your palm, you never really touch it. What you feel are the electrons repeling against each other. If the force is great enough, you will break the bonds between atoms, but you will never actually touch it.
So when you cut, lets say metal, you never really "cut" metal but you just split the bonds between the atoms.
I could be totally wrong...
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Post by BlueDolphin on Nov 9, 2006 15:38:40 GMT -5
Well that is a bit different. Physically, when we say touch we really mean bring close enough together to make a force between them. So we are touching the table even if the atoms arn't
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Post by dietspam16 on Nov 9, 2006 16:04:43 GMT -5
Personally, I find Zeno's paradox to be a really well-phrased pile of crap.
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Post by BlueDolphin on Nov 9, 2006 16:09:58 GMT -5
Why is that?
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Post by Monolith on Nov 9, 2006 17:39:11 GMT -5
I don't see why that means that motion does not exist. In fact, it has nothing to do with motion, just location. Velocity does not equal displacement.
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Post by Arachis on Nov 9, 2006 19:28:00 GMT -5
I agree with nick.
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Post by Evilduck on Nov 9, 2006 23:07:06 GMT -5
Motion is displacement.
Also, the other part of the paradox is that at any instant in time the arrow appears to be standing still. If you take a picture in mid flight, there is nothing about the arrow that indicates it is moving. Essentially the arrow is never moving because it is always in a "freeze frame" state.
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Post by Little Miss Odd on Nov 9, 2006 23:09:02 GMT -5
Jeff's post about .999... reminded me of Zeno's paradox, which goes as follows: Motion does not exist. For an arrow to reach it's target, first it must cover half the distance, then a quarter, then an eighth, then a sixteenth of the distance and so on. If the interval between arrow and target is halved each time, the arrow will never reach the target. So we're just imagining the arrow going from point A to point B? I fail to see how anyone can think this disproves motion. At any single point in time, the arrow, which we shall now turn into a point because we have that prerogative, is at some position x. By taking an interval of time t that approaches 0 you simply show that the function of the arrow's flight is continuous. The arrow is never at rest until it hits the damn target, because infinity is a concept, and with a big red bullseye in the way, the arrow can't exactly continue on forever. Zeno was a very special little boy, and he's just lucky he never had to take physics. Because it becomes rather obvious he wouldn't have survived a day in Yochum's classroom.
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Post by Archagon on Nov 9, 2006 23:12:54 GMT -5
Zeno just got pwned. ;D
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Post by Monolith on Nov 12, 2006 19:15:25 GMT -5
After a quick jog through my College Physics textbook, motion is a vague term encompassing displacement, velocity, and aceleration. You could also go by Newton's definition (an object in motion stays in motion) which would reffer explicitly to velocity. That rather silly little 'paradox' fails to even address the concept of constant velocity, and instead treats the 'motion' (i.e. displacement over time) as a curve with an asymptope at the destination's location, which is not true unless the object is decelerating. Unless I'm wrong on some point, case closed.
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Post by Paveltc on Nov 12, 2006 23:52:02 GMT -5
Zeno's paradox about the division of space is one of his other ones.
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Post by Monolith on Nov 13, 2006 2:06:42 GMT -5
That sounds better but is still flawed. An arrow will only not be moving if time is completely frozen, i.e. delta time equals 0. If you add more of these instants together: 0+0=0 and thus time is not passing. So it is true that an object is not moving when time is not passing.
F- for Mr. Zeno.
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Post by dietspam16 on Nov 13, 2006 11:13:30 GMT -5
So far all anyone has done is prove my original point.
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Post by Arachis on Nov 13, 2006 13:38:37 GMT -5
the other flaw is that zeno assumes that velocity is equal to distance over time, whereas in fact, distance over time is just the method we use to calculate velocity. Even if you take an arrow and freeze time so that it is not moving, it still has a motion associated with it.
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