Grandpa -
My question is entirely that of curiosity.
I was watching an episode of star trek the other day when I had a
thought. My question is pertaining to Einstein's special theory of relativity in an absolute vacuum.
Consider the following: an object in space, in a complete vacuum without
any boundaries or reference points. Essentially
an empty universe. Let's say that
the object was moving at a certain velocity, any velocity, doesn't matter what
it is. Velocity by definition is,
distance traveled per unit time. Now
without any reference points distance cannot be calculated and conversely
neither can velocity. So the thought came to me.
Is there such a thing as velocity in a complete vacuum? Since velocity is relative it cannot be calculated in a
vacuum, so it can therefore be assumed that velocity does not exist in a vacuum
(my entire question in dependant on the preceding postulate).
Einstein's special theory of relativity states that matter cannot travel
at or beyond the speed of light. So, my question is, can the special theory of
relativity be applied to such a scenario, where velocity cannot be measured or
even exist for that matter?
Thank you for you time in reading my email. I
hope that I didn't burden you with an ignorant question, since I'm only 18 years
old and am not exactly "well versed" in any of Einstein's theories
cosmology, or whatever field of physics this question may be related to.
Jake Marar
Sent
from AllExperts.com at 24 Aug 2000
Note:
Grandpa is also a listed expert for physics at this site - Some examples come
from there.
Jake -
Very good thinking process. From
thinking like this, many new things come.
There is much that travels in essentially a complete vacuum.
Most of matter is empty space. The
electrons associated with an atom or molecule travel within a vacuum.
Your question is not about vacuum, but about an empty universe, except
for the one object under consideration. Wherever
you are considering it from, we may regard it to have a velocity with respect to
that place. If you must consider
this object without existing yourself, you have an interesting mind experiment.
You are, of course, imagining the impossible, and this puts us in a place
where we cannot know the answers. The
thought process is nonetheless a very good exercise.
As I do the mind experiment, I think:
"This object could not have a velocity.
This object would be the universe.
The universe is 'all that is,' and this imagined object is 'all that is.' There could be no 'space' outside this object.
Now I will imagine that I am the object.
Where can I travel to? There
is no place to go. On what road may
I travel? There is no road. I am the universe; I cannot travel to non-existent places
taking non-existent routes. Now if
I could wiggle my fingers, then I could consider their velocity relative to
other parts of me, but now I am not a single object; now I am many objects, and
that was not the question. I can
imagine that object splitting into two objects and separating at some velocity.
Then I would have linear velocity relative to the other object.
I still could not have rotational motion of one object about the other,
though I could have rotation of either object about its own axis, because I
could see that motion relative to the other object.
With three objects, I could have two of them rotating about one another
and observe that from the third object."
Space is a concept, which comes about due to the existence of
"stuff," for the space to be between. Space is not a thing; it is nothing, (no thing), except a
mind-made concept. The concept of
"love" between two people is like this; it can exist only if the two
people exist. The problem that
makes "space" seem more material to us, is that we imagine it to have
"dimensions." Those
dimensions exist only because there is "stuff" to measure the distance
between. We have a psychological
need to assign dimensions to concepts (that are not things) we want to
understand. A child tries to assign
dimensions to love by holding his hands wide apart and declaring, "I love
you this much."
Great scientists, including Albert Einstein, considered at great
length the issue of space as either "nothing," or as an
"ether." Science is still
not completely agreed on this issue. Your
question, using your phrase "complete vacuum," must be considering
space as not consisting of an "ether," but consisting of exactly
nothing. If there were an
"ether," then we could consider your object's travel
"through" that ether at some "velocity" relative to that
ether.
We are used to thinking of "places" as things.
I could show you an empty table and ask you, "How much space is
there between the two oranges?" You
would answer, "What two oranges?"
But if I put two oranges on the table about three feet apart and then
asked the same question, you would answer, "About three feet."
Those same three feet were there without the oranges, but no
"space" between oranges was recognized. We can all see that "area" of the table, but that's
because we may associate the "space" with all kinds of other things -
the edges of the table, for example, ourselves or the carpet and other things in
the room.
You're right that velocity only exists with reference to something.
We are traveling about a thousand miles per hour rotating with the Earth. Many thousands of miles per hour around the Sun, and much
faster than that as we travel with the Sun around the galaxy - and I suppose
again even faster than that as we travel with our Milky Way around the universe.
If we buy the big bang concept of the beginning (or this particular
beginning) - then we have at the outset, your proposition.
A point with nothing else around it.
That one point contains all the energy/mass that will become the entire
universe. Since it is our regard
that nothing else exists outside that point, I've often wondered - "Is
there space (empty) outside that point?"
I think, with the assumption of the big bang, that the answer has to be
no. There is not only nothing out
there, but no space for anything either. There
is no "out there." The
one point is the only "place" that exists.
I am not a big proponent of the big bang - and the second law (of
thermodynamics) bothers me.
I'm going to attach an essay I wrote years ago - for your possible
interest. I cannot answer your
question with more than hints. What
you are doing is common in physics. We
call them "mind experiments." I
think I remember a word (which I cannot find in the dictionary) "gedankin."
I think it's the German word Einstein used, meaning roughly, "mind
experiment." There are many
things we cannot test with "real" experiments, and so we use gedankins
to consider these things.
- Grandpa