Ask A Scientist Physics Archive

name         Danny
status       other
grade        other
location     N/A

Question -   Hi! I am an average 17 year old studying at college in
the UK. this may sound odd but.. are any of us actually here? I
understand that atoms have a nucleus and electrons that orbit etc... and
that every and anything is made out of them in a specific arrangement
which makes different materials BUT in between them is Nothing. But if
there is nothing there how can we exist? that would mean were 99.9%
nothing if I am correct, but how do we see feel taste and sense things if
were not there? A lot of questions your maybe thinking but out of general
curiosity WHY?
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Danny-
    It seems to me that most of nature is mostly nothing with occasional
interesting somethings.
It can take a lot of roaming around to find the interesting somethings,
but that is what is important, cause they are actually out there,
  doing important acts to other important-but-scarce somethings,
whether you find them or not.
It is always the little somethings in the mostly-void that really matter.

So personally, I think you really exist, OK?

Of course this is all beer and philosophy, not science.

Jim Swenson
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Hi, Danny,

You are absolutely right in that we are almost entirely "nothing", by which
I presume we both mean vacuum.

First, I would like to point out that the vacuum is extremely complicated.
It contains large amounts of matter which is in negative energy states, but
which can briefly appear in our world in accordance with the Heisenberg
Uncertainty Principle.  A high energy photon (quantum of light), for
example, can produce an electron-positron pair out of the vacuum.  It must
do it in the field of a nucleus or other charged particle to conserve energy
and momentum, but it does produce particles (an electron and a positron = a
positive electron = an anti-electron) out of the vacuum, so they must have
been there before!

The more important answer to your questions is that particles interact while
separated by the exchange of particles (bosons) which carry the force field.
So photons carry the electromagnetic field and, for example are responsible
for the forces between electrons and the nucleus to which they are bound by
the electromagnetic force.  Similarly, quarks carry the strong force which
binds 3 quarks together in a proton or neutron and the protons and neutrons
together in a nucleus, the intermediate bosons carry the weak force which is
responsible for radioactive decays, and presumably gravitons (as yet
unobserved) carry the gravitational force.

Strangely, the universe is even emptier than you describe since particles
such as electrons, quarks and photons are point particles.  That means they
have ZERO size!

It is indeed a weird universe, but it is our universe.  In fact, all these
weird features may be essential to make a universe in which human life is
possible.  I could say a lot more about this, but in the end I cannot
explain it.  In fact, nobody can!

Best, Dick Plano, Professor of Physics emeritus, Rutgers University
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Danny,
What is between the particles, what composes most of your "volume" are the
forces between the particles.  Energy is constantly passing back and
forth between the particles that compose everything.  Both waves and
temporary particles (muons, pions, gluons, photons, etc.) are constantly
traveling from particle to particle, carrying this energy all around.

Consider "chicken wire".  This is a wire fencing with very little mass,
mostly empty space between the wires, usually woven in a hexagonal pattern.
Although chicken wire is almost "empty", it is still very strong.  The design
gives it the strength, not the mass.

Compared to the volume it takes up, a well-designed bridge has very little
steel.  The structure and rivets give the bridge most of its strength.
Steel bars joined with duct tape, or bars joined in squares rather than
triangles, would produce a collapsed bridge.

Your body's affects on the rest of the universe are not due to the huge
amount of material.  The energy stored within the atoms, kinetic energy and
mass energy (i.e. mc^2), and within the forces, potential energy, powers the
interactions.  The forces transfer the energy.  Your body exists, you body
is there, mostly due to its forces and energies.  The chosen atoms, put
together in the chosen designs, direct those forces and energies to do as
needed.  Your body is much more than atoms.

God bless you,
Ken Mellendorf
Math, Science, Engineering
Illinois Central College
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In one sense you are correct -- space is mostly empty. However, this is
really an artifact of holding on to a macroscopic view that electrons are
particles whizzing around a nucleus. That is not how nature behaves at the
atomic level. The position and momentum of an electron is probabilistic so
that all you can say about the position of an electron is that it has a
certain probability of being located at a particular position. In that
sense the electron "fills" all the space.

Vince Calder
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