If matter really consists of mostly empty space, why do objects have defined boundaries?

Probably a layman's question in terms of physics, but I've read some on the idea that some physicists claim matter doesn't exist in the common sense, because all matter is really made up of atoms, which are subatomic particles vibrating around large empty space.

If this is the case, why can I, for example, push against a brick wall and experience nothing but resistance to the object? If the brick wall consists of subatomic particles vibrating around mainly empty space, and my body is of this same makeup, why is a seemingly real physical/material resistance encountered? What is the quantum-physics explanation of this?



Vandan thanks for the detailed answer.

You say these forces are magnetic, at least at the sub-atomic level. This sounds like a stupid question to me, but if an external magnet was held near my hand or the brick, why does it not change anything within the magnetic force bonding the particles together?

Are electric forces also at work? What other forces come into play at the atomic or molecular level? Are all of these forces well understood by modern physics?

7 Answers

  • 9 years ago
    Favorite Answer

    I think it's time for you to buy or rent a copy of "The Elegant Universe" by Brian Greene to get the straight skinny on the subject. You have several misconceptions that need to be set straight.

    For one, "...matter doesn't exist in the common sense, because all matter is really made up of atoms, which are subatomic particles vibrating around large empty space."

    Atoms are not "subatomic" particles, they are atomic particles. Sub means lower than; in this case, lower than the atom. Atoms are on the same level as atoms, not lower than. Lower than, components of an atom, include protons, neutrons, and electrons. These are subatomic particles; they are components to the atom.

    There are even subatomic particles to the protons and neutrons. They are called quarks, which are components of the protons and neutrons. One might even call quarks sub-subatomic particles; although no one ever does.

    On the other hand, the electron has no further definable components. It's about as "subatomic" as one can get.

    That aside, your comment asserting matter doesn't exist because it's made up of atoms overlooks the fact that atoms are mass. They are matter. In fact, matter exists because of the atoms, without which there would be no matter. Atoms (actually their quarks) are the lowest unit of matter.

    You are right about one thing; there is a whole lot of space, unoccupied by mass round each atom. But that's where that emptiness ends, with the mass. In fact, each and every atom is surrounded by an electro-magnetic force (EMF) field. And that fills in all the space between the atoms. The EMF comes from all those bonded electrons flitting about each atom.

    It is in fact the EMF of the atoms in your chair that keeps the atoms in your butt from merging with the atoms of the chair as you sink slowly into the center of the Earth. That is, the EMF of the chair pan and the EMF of your butt atoms repel each other. (Yep, I said your butt is repulsive.) And that's why you don't drop on through the chair and the Earth under the pull of gravity.

    In fact, two bodies, like your chair pan and your butt, do not really touch each other at their boundaries. Their respective atoms and molecules are kept apart by the repulsion between their respective EMF fields.

    At the atomic level, you would see irregular layout of the atoms along the surfaces. But that evens out as we pull back and look at surfaces without the aid of powerful viewing devices. With the naked eye, many, if not most, objects appear to have sharp, but smooth surface boundaries. But at the atomic level, they are really quite irregular.

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  • 9 years ago

    You have good answers already. In answer to your additional details, the forces are NOT magnetic at the sub-atomic level. It's called the "electromagnetic force" but what's going on between electrons and protons at that level is that aspect of the electromagnetic force called "electrostatic attraction". It's a positive charge attracting a negative charge, and vice versa. This is not affected by magnets.

    Yes, it's an electric force.

    Magnetic forces do come into effect in magnetic materials, because electrons are also tiny magnets. But most materials do not get affected by magnets because electrons come in magnetic pairs, one north-south and one south-north, which cancel out any such effects.

    The electromagnetic force is extremely well understood by modern physics.

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  • Vandan
    Lv 4
    9 years ago

    Although these very small things are moving in a relatively large space... There are trillions probably more like quadrillions or even octillions of atoms there... And these are all bound together by magnetic forces.... These are then held in shape by yet more magnetism... The names of the 2 forces inside the atom are the strong and weak atomic force... The strong is the gluon force holding quarks together... The weak is that which holds the nucleus together...

    In the brick itself now that we are out of the atom... We get to the intermolecular forces... Now these then hold the substance together... And form a new substance or object... Because of all of these forces you then get the resistance...

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  • 9 years ago

    Imagine you're standing in an open field. In one hand you have a baseball attached to a 10 foot rope. You stand in one place and spin the ball on the rope around you, creating an open space, but one where another person could not stand safety. Now imagine there's another person swinging their own baseball on a rope. The two of you would have at least 20 ft between you, but you effectively take up a lot of space.

    Now imagine instead of a baseball, it's a penny. And instead of 10 ft of rope, it's 10 miles of rope. And you're floating, and the penny is spinning around you in all directions. Also the penny is moving so fast that it could be said to be in any point in its trajectory at any time. That's what it would be like to be a Hydrogen atom.

    While it is mostly empty space in the middle, you would have a hard time getting past the effective shell created by the super fast penny.

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  • 9 years ago

    The field created by the electrons in the atoms of the surface of the skin is being repelled by the field created by the electrons in the atoms of the wall.

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  • 9 years ago

    What we experience as contact between surfaces of objects is the effect electric repulsion between the electric fields of the surface electrons.

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  • 3 years ago

    Electromagnetic forces carry us up. that's real: once you push the mouse button such as your finger, or bash your head on a wood door physique, the stress by ability of which that interplay happens is the comparable by way of fact the stress that sticks a party balloon to the wall once you rub it on your hair, or that makes magnets come mutually. that's basically manifesting over a plenty shorter distance. All that belongings you concept grow to be 'solid' particularly isn't solid in any respect, that's basically a cloud that bounces off different clouds by way of fact of power fields between them. meanwhile, real solid count- i.e. neutronium- is so dense that in case you had a bite the size of a grain of rice on your hand, it may weigh basically approximately 50 cases as plenty by way of fact the Sears Tower, and could slip by using your arms, harm its way for the period of the floor devoid of even pretty slowing down, and proceed drilling its way by using bedrock in direction of the midsection of the Earth. And a sphere of neutronium the size of a significant watermelon could have as plenty floor gravity by way of fact the Earth itself.

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