Doubochinski’s
Pendulum
preliminary thoughts
Ernest Wong
# 1
NZYPT 2015 Question 6
Make a light pendulum with a small magnet at the free end.
An adjacent electromagnet connected to an AC power source of a much higher frequency than the natural frequency of the pendulum can lead to undamped oscillations with various amplitudes.
Study and explain the phenomenon.
# 2
Previous Work
# 3
Discovery
# 4
In 1968–1969,
the brothers, Danil and Yakov Doubochinski,
discovered interesting phenomenons with this pendulum.
They called it amplitude quantization.
# 5
Usually the max angles of the pendulum
Restricting to discrete values.
Amplitude
Quantization
# 6
Moreover, these amplitudes are
Stable
Video Demo
# 7
Intro Reading
# 7
But magazine known for its
pseudoscience
Very readable
Mechanisms
# 7
Phase regulation
Velocity modulation
Velocity Modulation
# 7
Articles In the Past
# 7
1973
1989
2000
Asynchronous Excitation of Undamped Oscillations
# 7
1973
Velocity modulation
Exhibits in systems with short interaction space.
Articles In the Past
# 7
1973
1989
2000
More...
# 8
2006
Doubonchinsky’s Pendulum
By Ernest Wong
