Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Why I like spheres and how things may tend to look like them

  1. Jul 16, 2010 #1
    In space-time I like to think of objects going through a "stream" of movements that remain concrete in the 4 dimensions of space-time, all movements being inter-related with one another with respect to the frame of reference. But let's compress this stream so only what remains is the overall average of the movements made by the object in space-time. I envision a sort of spherical shape. The less an object tends to move it's parts the more it will appear to be spherical in form.

    Imagine a tree, to help look at this image http://www.sustland.umn.edu/implement/images/planting_fig1a.gif

    Gives you an idea as to how an object can appear to look like a sphere. A tree doesn't move very quickly relative to the earth year, or the ground for that matter, so it doesn't really change its form much from that of a sphere.

    Now imagine a human being, in the form illustrated by Leonardo Da Vinci
    http://www.enchantedlearning.com/artists/davinci/gifs/proportions.GIF

    As you can see, the human doesn't look like that much of a sphere. Overtime, on average however, the human will tend to look like a sphere. Waving your limbs around in the 3 dimensions of space will allow you to see that you can indeed look more like a sphere, but this is only averaged overtime.

    The connection to the tree and the human is this: The tree moves a lot slower relative to the human being. The human being moves a lot faster relative to the tree. The tree will tend to look more like a sphere because of it's relative speed to that of the ground of Earth or it's inertness, if I am using that right.

    The Earth looks quite like a sphere, though it's moving fast. But we're talking relativity.

    Am I making sense here or is this ridiculous?
     
  2. jcsd
  3. Jul 17, 2010 #2

    Math Is Hard

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I don't see this as meaningful to a philosopher or a physicist, but I can see how a poet, novelist, or filmmaker could create something mentally entertaining with it.
     
  4. Jul 17, 2010 #3
    Thank you for your comments, Math is Hard. I, too, do not find any application for such thought. It is just peculiar that things will tend to shape themselves as spheres in this universe, if you suppose time a little differently.

    I thought about this for many animals and things. The hardest one so far is the snake, which would have to wiggle quite a bit to tend to look like a sphere. But indeed, it would, averaged overtime. So many things tend to look like spheres. Also, as something ages, it's sphere size changes. A baby for instance has a smaller sphere than an adult.

    We think of atoms in two different ways. Bohr's Model, which describes the atom as a 'mini solar system'. Doesn't this, sort of as well look like a sphere? Then we see the wave probability of the atom and it's particles and we find that, averaged over time yet again, the particle will tend to look like a sphere or a billiard ball. Even in wave form, it tends to look like a sphere.

    You find spheres all over in nature, including the planets, stars, galaxies tend to spiral and turn in nature. There are a lot.

    My question is: Why? Why do things tend to look like spheres? Is it because of the 3 dimensions of space, or is there another more subtle reason to this? Do Membranes in M-theory have anything to do with this line of logic? Probability of tendency in shape?

    I do see, though, that this is far from applicable in Philosophy or Physics, but the thought that reality tends to work this way still exists and we can be left to ponder why.
     
  5. Jul 17, 2010 #4
    It is actually an ancient question in metaphysics and physics dealing with idea that symmetry or proportion apply to everything.

    Modern physical theories tend to have what is called "supersymmetry". This is a type of symmetry that always looks the same from every direction, even if you cut the figure into little pieces. For example, cut one of your spheres up and you just get more spheres. A holographic picture of a ball is a common example of this type of symmetry. No matter how many piecies you cut the holographic film into each piece retains the overall picture of ball instead of a corner here, a center piece there.
     
  6. Jul 19, 2010 #5

    fuzzyfelt

    User Avatar
    Gold Member

    Last edited: Jul 20, 2010
  7. Aug 14, 2010 #6
    I like spheres because they represent flat planes in a coordinate matrix skewed by centripetal force. I wonder if anyone ever thinks that the same way the Earth appears flat on the surface, the solar system, galaxy, etc. might just appear flat because of our location on its "surface." I don't know how this could be possible considering that galaxies are observed to be flat at a far distance, but then maybe each galaxy is just a "plate" on the surface of an expanding sphere. Anyway, the point wasn't really to speculate but to illustrate that there is a perceptual tension between 2D planes and sphere-surfaces where centripetal force is present - I just wonder how much this effect could explain.
     
  8. Aug 15, 2010 #7
    Who needs centripetal force? A large enough sphere will appear to be flat in local areas, regardless of what forces are acting on it.
     
  9. Aug 15, 2010 #8
    I guess that's a good point, but wouldn't that be true of any 3D shape, such as an egg or a doughnut? I like the centripetal force because it causes the sphere's surface to be literally flat in terms of all lines of force being perpendicular to the surface. Would this be true of any other 3D shape?
     
  10. Aug 15, 2010 #9
    Sure. But objects with a much higher curvature would have to be relatively larger to provide that same sense of "flatness".
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook