| Topic: |
Science > Physics |
| User: |
"" |
| Date: |
04 Oct 2005 02:25:05 PM |
| Object: |
Light independent orientation (Lio) |
By counting the steps taken on a walk to the next village we can
measure the distance to it, and this measurement can be improved. No
thing is eternal, so an earthquake might change this distance, but we
can find out, that the length of the path is independent from how
quick we move and other pecularities. Distance is the constant, not
changing property of things, a part of the form or space , in
opposition to time, where we choose a most regular movement, to measure
the change of other movements.
Mathematical functions are in analogy to this, are alike this with
constants (like space), with an independent variable (like time or a
most regular motion), giving any movement as the dependent variable.
Since James Clerk Maxwell wrote 1873/1891 in
"A Treatise on Electricity and Magnetism" just on the first pages about
the three fundamental units in physics: "In the present state of
science the most universal standard of length which we could assume
would be the wave length .... of light (with well defined lines in its
spectrum)....Such a standard would be independent of any changes in the
dimension of earth, and should be adopted by those who expect their
writings to be more permanent than that body." we achieved with light
the most precise measurements, up to the spectacular distances of the
voyager. Here we could measure the distance by counting the
oscillations of electromagnetic waves (to put it simple), and so the
precision was independent of the distance of the voyager. And this led
to GPS, a modern means of orientation.
To measure the distance to the next village, we need something which is
different from it, a yard stick, our step. So in a way in dealing with
light it might be useful to have something different from it, (and may
be also in light observed in thought-experiments) and there might be
some other use.
Of course we cannot take light out of our universe, as there is only
our universe, just as we canot miss one flapping of the wings of a
butterfly. But when we step on a scale, we can consider just one
physical property, without relating it to the humidity on mars or the
emotional state of our mind.
Besides distance there is direction.
The nice people of the Science Museum in London
http://www.sciencemuseum.org.uk/
caring for a pendulum of Foucault gave away a secret to me: if we would
take the pendulum to the north or south pole the earth will rotate once
a day under it. But how long is this, expressed with our clocks ? It's
more like four minutes less than 24 hours. From it i conclude, there is
a space with directions and the observation of the fix-stars can give
some impression of it, as they are so far away, that their and our
movement will not affect it much. This is prominent example of Light
independent orientation (Lio)
For the same purpose in spacecrafts a gyroscope is used, often on a
platform together with instruments measuring acceleration.It's not only
good to fix a direction in space, it's for this reason also good for
measuring time. If we take for example earth rotation as the standard,
which it was till recently, when is one revolution completed ? This can
be measured by pendulum or gyroscope and than it's independent in
observing light (from the stars).
But there is much more to orientation so finally, i would ask You to
provide Your examples of Lio.
Sincerely Yours
Hero
.
|
|
| User: "" |
|
| Title: Re: Light independent orientation (Lio) |
09 Oct 2005 10:53:23 AM |
|
|
wrote:
.....
Another example of Lio is the movement of the waters, the tides. Tea
in cups will respond to the movements of the untrained waiter, bringing
it to Your table, as he did not learn yet to counteract the movements
of the body by keeping his hand steady in respect to the room. Water
masses at different locations in earth have different distances from
the moon and so the gravitational pull is different too (NB. the effect
is greatest on tangents from moon to earth, where it is at right angles
with the gravitational pull of earth), the sun is pulling too and there
are the movements of earth, around the sun, around the center of the
system earth-moon and the rotation of earth in space - each component
expresses in a tide, denoted by letters like M and S, and the "harmonic
analysis" of Lord Kelvin explicitely delivers the K1 tide, 4 Minutes
less than 24 hours, and K2 in half the time, reflecting the rotation of
earth in space.
Any more examples known?
Actually, do the instruments measuring acceleration in space crafts
measure rocket thrust only or do they measure gravitational
acceleration too ?
Have fun
Hero
.
|
|
|
|
|
Related Articles |
|
|
