Ask A Scientist© Physics Archive

name         Richard H.
status       educator
age          50s

Question -   My position is that nothing "nonphysical" (ie, supernatural,
immaterial) can exist in our universe. How can I clearly explain to
high school students that "waves" (as in a photon can be both a
particle and a wave) and "energy" are not "nonphysical" things, but
are physical things (that obey the laws of physics, like all other
physical things that exist in our world). Thanks for helping.
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Richard,
         I would not actually say a photon is a particle and a wave.  Before
modern times, the "model" of the universe included two kinds of objects:
particles and waves.  It has turned out that this model is incorrect.  There
are many kinds of objects in the universe.  Most of these objects have some
particle properties and some wave properties.  Electrons have more particle
than wave properties, but they do have a few wave properties.  Photons have
quite a few properties of both particles and waves.  There are no pure
particles or pure waves until you get to objects much bigger than an average
molecule.
         Physics does not claim that "nonphysical" things cannot exist.
Physics claims that "nonphysical" things are not part of the model of the
universe that we use.  Some objects in quantum mechanics may or may not
exist.  We have never seen a gluon.  We do not know whether they exist.
Models of quarks and gluons do explain high energy experimental results.  We
do not know whether it is the correct explanation.
         Physics provides a way to understand how the universe works.  It
assumes that there is some order to things.  It assumes that we can
understand this order.  It in turn provides us with tools to make
predictions about the physical world.  If G-d chooses to temporarily alter
how something behaves, physics does not try to explain it.  It is not part
of the model.  When G-d lets things proceed on their own is what physicists
attempt to deal with.

Dr. Ken Mellendorf
Illinois Central College
========================================================
Since I do not agree with the proposition, I do not know of reasons to support
it.

The meanings of the words "nothing", "nonphysical", "can", "exist", "our", and
"universe" are rather ambiguous, and of course change with time.  Your 
statement
could be justifiable if and only if we assume that one has a priori and 
complete
knowledge of knowns, unknowns, knowables, and unknowables of and for all 
times.

How could we be aware of existence or lack of existence of non-physicals 
if we,
as physical being, are limited to physical probes and means to sense 
effects and
establish existence?

With regards to waves, energy, and the like, these are words used to denote
observable physical phenomena or concepts that convey the effects, 
implications,
or consequences of physical phenomena.   These are or ought to be observable
directly or indirectly (through their effect) by way of physical examination.

AK

--
Ali Khounsary, Ph.D.
Advanced Photon Source
Argonne National Laboratory
========================================================
Hi, Richard !!!

You propose that "nothing nonphysical can exist in our universe",
like - for instance - supernatural or immaterial. And you wish to
explain that "waves" and "energy" are nonphysical things but
obey laws of physics like all other physical things, so that they
belong to the physical world..

Well, first of all, you know that theories are created aiming to explain
a given existing phenomenon. The phenomenon "light" can be
explained like particles that travel in linear course, but shows
interference properties, which proves that are waves ( only waves
behave like this ).

To explain the atom, the scientists developed several models :
Thomson, Rutherford, Bohr, Orbital Model (probability of finding
electrons) and now the Quarks theory.

Einstein said : E=mc2 so that matter is a "concentrated form of
energy". The gravity can attract light and make it bend. Is gravity
a physical or non-physical phenomenon ?? Gravity exists, for sure !!
But nobody knows exactly what gravity is. Do we live in a universe
where the gravity is "positive" and is there another part of the
universe where the gravity is "negative" ??  Is there gravity waves ??

And, what about the "negative" charge of the electron ?? What is
electrical charge ? Why is that a "negative" charge attracts a "positive"
charge ?? Newton proposed that light is emission of particles.
Christian Huygens said that light is a wave.
Maxwell proposed that light is an "electromagnetic" wave
resulting from the movement of an electric charge and proved that
its velocity is the velocity of light. Plank said that energy can be
considered as "quanta" and Einstein explained the nature of
photons with the use of this concept.

As you can see, this is the evolution of theory, alway running
behind the facts.

Now - at last !!! - back to your question in the point you say
that "nothing non-physical can exist in our universe", and
"wave and energy are non-physical things but are ideed
physical, as the obey laws of physics". I believe that it is
NOT an easy task the explain and you have to be flexibel
and consider that the last word has not till now been pronounced.
One simple question may origin a lot of other questions.
A new doubt, a new question requires a new key, a new
explanation. Nothing supernatural, for sure, everything
has to have its explanation.

I do not believe in Ghosts, but that they exist...they exist !!!

Alcir Grohmann
========================================================
Perhaps you should use terms like "testable" and "non-testable" in place 
of the
terms "physical" and "non-physical".

Science is about things that can be studied using the scientific 
method.  That is,
observations lead to hypotheses that are then tested.  If a hypothesis 
cannot be
tested then it is of no value in science.  A test is used to look for 
cause and
effect relationships.   When a hypothesis is shown to be true by testing (and
independent verification by other groups) it becomes a part of the "physical
laws".  Note that sometimes the tests are beyond current technology and it 
is many
years before they can be performed and the physical laws updated.

While scientists may have opinions about non-testable concepts, we must be 
careful
not to view them in the same way as we do scientific theories.  In the 
situation
you are describing I would simply say that science has nothing to say about
certain subjects, other than that they are non-testable.  Remember that for
something to be incorporated into the "physical laws" the results of the test
should be reproducible.

  Greg Bradburn
========================================================
Dear Richard. Perhaps you would read my texplanations of
'How do we See' and 'Time'
These are on www.distantview.net

Kind regards.
Prof. Leonard Shaw
=========================================================