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Origin of Energy
Name: Elvis D.
Status: student
Age: N/A
Location: N/A
Country: N/A
Date: N/A
Question:
Energy can neither be created nor can be
destroyed but only can be transformed.
This is one of the most important statement in physics, "The Law
of the Conservation of Energy"
If this is true, then when did the first energy come from? i.e.
Was energy created at the origin of the universe?
Replies:
There are two issues here. Neither is easy, nor obvious:
The first is that "energy" is an abstraction. This is a
difficult concept to get a grip on because energy is slipped into
our thinking so "smoothly" and so soon in our physics
education. It is made to appear so sacred, so "obvious" that who
dares challenge the conservation laws! But look what happens in the
practice of teaching "elementary" physics. We immediately invoke
friction-free inclined planes, pulleys, etc. because if we do not
then "energy" is not conserved because of friction and heat losses.
Then enters thermodynamics: which deals with the conversions of
mechanical work and heat, but look what has to be done -- idealized
"reversible" infinitely slow processes must be invoked to "save" the
laws of conservation.
Theoreticians, especially Emmy Noether, in the 1930's were truly
concerned about the laws of conservation and another aspect of
physical laws, namely their symmetry. She proved mathematically
that a quantity is conserved, if and only if, some element of
symmetry is preserved. Energy is "conserved" because the equations
governing energy are symmetric with respect to "time". Momentum is
"conserved" because the equations governing momentum are symmetric
with respect to "space coordinates". Angular momentum is
"conserved" because the equations governing angular momentum are
symmetric with respect to "rotation".
We should not lose sight of the fact that the properties of some
very obscure particles were predicted based upon other conservation
laws holding true, without the particles ever having been observed
experimentally. That is certainly a leap of "faith".
The second part of your question has to do with what happened
"once upon a time" in the first microscopic fractions of a second
after the creation of the Universe. And to the extent that I am
able to fathom the problem, the honest answer is, "No one knows.".
Vince Calder
Elvis,
If the universe began with a "Big Bang", then the energy had to have already
been here.
One theory is that it was all compressed into tightly packed matter. Energy
can be in the form of matter, based on Einstein's E=mc^2. That tightly
packed matter then exploded, much of the matter-energy converting into other
forms.
Another theory is oscillation. The universe has always been here, and
always will be. The universe expands to a certain limit, and then it
collapses back to its compressed form. The universe does this repeatedly.
It always has been oscillating and always will be oscillating.
Both of the above assume that the universe is all that exists. It is
possible that other sources of energy do exist, other universes, other
dimensions, a variety of possibilities. Because we would have no way to
measure such a thing, science tends to limit itself to the first two
options. We really have no way to know which is true.
Dr. Ken Mellendorf
Physics Instructor
Illinois Central College
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Update: June 2012
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