This is an excerpt from my Tour the Force.
Experiment #1
Set up:
1) 1 pc 4" x 3" x 16 Ga sheet of 99% cold rolled copper suspended by two
60" long fishing lines at two neighbouring corners (to prevent spinning)
in a vertical orientation of its plane with its lower edge 1/16" above a
wooden desk.
2) 1 sheet squared paper taped on top of the desk and used as a rough
scale.
3) 1 permanent magnet from a speaker with its soft steel core removed
and with an approximate pull of 15 lbs. on contact with mild steel.
Observations :
a) - When the magnet is being brought to the proximity of the copper
sheet perpendicularly to its plane, the sheet is initially repulsed from
the vertical. Then the copper slowly returns back to vertical and
steadies with no observable declination in a steady field of the magnet
left motionless in the immediate proximity of the sheet. If there is any
remanent decline from a vertical due to the claimed diamagnetism of
copper, it is too small to be observed by this set up.
- The faster is the approach of the magnet to the sheet, the faster and
greater is the initial declination of the sheet, up to a point when the
rate of effect reverses.
b) - When the magnet is being retracted from the sheet, the sheet
follows it out of the vertical up to a point, as if attracted.
- The faster is the retraction of the magnet from the sheet, the faster
and greater is the initial declination of the sheet, up to a point when
the effect reverses
The qualitative behaviour seems independent of the magnet orientation
in both cases.
Experiment #2
Set up is the same, except the same sheet of copper was thermally
annealed at approximately 700 C.
Observations:
Yields the same qualitative results, but it is readily observable that
they are quantitatively pronounced compared to #1 with no observable
declination of the sheet from vertical in a steady magnetic field.
Experiment #3
Set up is the same, except the same sheet of copper was work hardened
to a point of brittleness
Observations:
a) The sheet almost ceases to get initially repulsed by approaching
magnetic field.
b) The sheet is noticeably attracted by a steady magnetic field. *
* Even though the sheet may have been contaminated by steel from a
hammer and an anvil, the contamination could not be high enough to
account for the degree of declination in a steady field. I should have
annealed it again and see. It did not occur to me at the time. I am
sorry that I was sloppy. Since this observation was not relevant to
further argumentation, I did not bother to redo it.
Experiment #4
Set up is the same except that the sheet is replaced by a piece of 99%
pure cold rolled copper 3/4" diameter round bar of the same weight as
the sheet. It is again suspended in horizontal position by two 60" long
fishing lines at its ends (to prevent spinning), with its lower edge
1/16" above a wooden desk.
Observations:
This experiment yields the same qualitative results as experiment #1
and #2, but barely observable.
My conclusion here was that the entrapped air was responsible for the
declinations.
Regards Slavek. Use as you may.
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