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Why is a straight line easier to draw fast than slow.

  1. Jan 3, 2008 #1
    Probably an easy question
    I thought that its easier to do things when you have more time.
  2. jcsd
  3. Jan 3, 2008 #2
    i right now dont have the answer ,but certainly it is an interesting question
  4. Jan 3, 2008 #3


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    There is an assumption in your question that a line that is "successfully drawn" is a line that is smooth, but is there an assumption that this same line be accurate? I don't think you considered this.

    You see, you might be able to draw a smooth line quickly, but can it be just any line? What if you are trying to follow a specific path? like say, detailing on a car? When detailers paint lines, they go slow.

    As for why you get a smooth line, that has to do with the difference between gross motor coordination and fine motor coordination.
  5. Jan 3, 2008 #4
    I think the easy answer might be the momentum of your hand and arm is much greater therefore less likely to deviate.
  6. Jan 3, 2008 #5
    Great question. With a little effort here I come and - Happy New Year to all. This is so refreshing and simple.

    Well, simple maybe but doesn't stop just yet.

    I think its about tremors in the muscles and avoiding obstacles from muscles and paper. Maybe it won't be accurate under all angles - thats ok. However, for that little time perhaps a man is becoming a projectile with a perfect motion instead of being only human with erratic motion.
  7. Jan 3, 2008 #6
    Well, if you draw any straight line, that's true. But if you have to draw a straight line through two given points, then it depends.
    The trick here I think is that your muscles bust out when you draw fast (or just any movements) like a spring and the trajectory is normally in a straight line
  8. Jan 3, 2008 #7


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    I would say momentum + not much time for your muscles to do the standard shiver.

    Another thing is, there wouldn't be much room for movement in the other dimension because you're restricting the amount of time you can take between A and B, if you go slow you should notice that the time isn't always constant, but it should be for going fast. Something similar to gyroscopic inertia.
  9. Jan 3, 2008 #8
    Good point, my fast lines are no more accurate for a predefined shape.
    Last edited: Jan 3, 2008
  10. Jan 3, 2008 #9


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    Right. But think it further. If might look straight, but did it hit the mark?

    Straight isn't the only criterion. Accuracy is too.

    Say you're drawing carefully - you're trying to draw a straight line from A to B - and your arm zigs and zags by 1mm. You get a wobbly line that deviates by 1mm, but you hit your mark.

    Now do the same thing, but do it quickly. Did it miss B by less than 1mm? I'll bet not. I'll bet it's off by a lot.

    I suspect that the OP is comparing apples to oranges. When drawing slowly, he's considering wobbliness and accuracy. When drawing quickly, he's is dropping the accuracy criteria.
  11. Jan 3, 2008 #10
    Kinda different, but it may be related. You can draw near perfect circles on a chalkboard(or similar, large drawing surface) by rotating your arm around the shoulder, using the shoulder joint to make a circle. It may be a similar but opposite effect, that achieves straight lines....maybe having to do with extending your arm straight out, as opposed to just moving the whole thing along as you draw.
    Last edited: Jan 3, 2008
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