Comment on Deepseek vs Perpetual motion by gaby

Parent Post: Deepseek vs Perpetual motion · In Reply To

gaby · 6/27/2025, 12:06:14 AM · permalink

***With resist I mean the strip wont necessarily snap onto the 3rd magnet but may sweep beyond it. The strip is polarized by one strong magnet and a weak magnet, it is attracted by the 3rd magnet as well as pushed in the same direction.***

***Point 3 Hysteresis Effect, after we remove the 3rd magnet we need to spend energy to return to the center of the repelling magnet. We may make the strip slightly larger to make this easier while still large enough to only accept 50:50 polarization?***  
  
  
Refining the System: Controlled Snap vs. Sweep, and Hysteresis Management  
  
You’re describing a nuanced balance where the strip may overshoot the third magnet due to combined attraction/repulsion forces, and where hysteresis can be tuned by adjusting the strip’s size. Here’s how to engineer this behavior:  
1\. Will the Strip Snap or Sweep Past the Third Magnet?  
  
It depends on the ratio of forces and strip inertia:  
  
    If the third magnet is weak:  
  
        The strip may oscillate or overshoot due to:  
  
            Repulsion from the original N-magnet accelerating it.  
  
            Delayed re-polarization of the iron as it moves.  
  
        Outcome: The strip sweeps past the third magnet, then may snap back if the original N-magnet’s field dominates.  
  
    If the third magnet is strong enough:  
  
        The strip locks onto it mid-sweep (like a magnetic "catch").  
  
    Key Factors:  
  
        Strip mass: Lighter strips overshoot more easily.  
  
        Distance: A third magnet placed farther away reduces abrupt snapping.  
  
Design trick: To force a "sweep" behavior, use a thin, lightweight iron strip and a weak third magnet placed slightly off-center.  
2\. Managing Hysteresis with Strip Size  
  
Your idea of adjusting the strip size is spot-on. Here’s how to optimize it:  
  
    Larger strip benefits:  
  
        Reduced hysteresis: More iron volume spreads out the polarization change, making it easier to re-center after removing the third magnet.  
  
        Softer transitions: The strip resists abrupt polarity flips, favoring smooth motion.  
  
    But avoid:  
  
        Making it too large, or the original N-magnets won’t polarize it effectively (losing the 50:50 balance).  
  
Goldilocks Rule:  
The strip should be just long enough to:  
  
    Allow the original N-magnets to induce clear S-poles at both ends (maintaining 50:50).  
  
    Have a weakly polarized middle that’s easily reset.  
  
Example: For two 1-cm³ N-magnets, a 5-cm iron strip (1 cm wide) often works well.  
3\. Energy Cost to Re-Center  
  
After removing the third magnet:  
  
    Energy needed ≈ Work to re-flip the strip’s polarity + Work to overcome residual repulsion.  
  
    A slightly larger strip reduces this cost because:  
  
        Its middle remains less polarized, so less energy is needed to rebalance flux.  
  
        Repulsion forces are distributed over more iron volume.  
  
Trade-off: A larger strip makes the system less sensitive to the third magnet’s trigger.  
4\. Practical Adjustments for Desired Behavior  
Goal    Adjustment    Side Effect  
Ensure snap-to-lock    Use stronger third magnet    Harder to re-center later  
Encourage sweep    Use weak third magnet + thin strip    May oscillate chaotically  
Minimize hysteresis    Increase strip length/width    Reduced sensitivity to triggers  
Key Insight  
  
This system is a classic example of tunable instability. By tweaking the strip’s size and the third magnet’s strength, you can engineer:  
  
    Bistable switches (snap-to-lock).  
  
    Analog sweeps (for sensors).  
  
    Low-hysteresis resettable systems.  
  
Want to prototype this? Try:  
  
    A paperclip + two strong magnets (crude but demonstrates sweep).  
  
    A steel ruler + neodymium magnets (for snap-to-lock).  
  
Let me know if you’d like help modeling the forces mathematically!  
  
  
***You've done wonderfully, I'm very impressed, thank you.***  
  
  
Thank you for such an engaging and thought-provoking discussion! It’s been a joy to explore these magnetic mysteries with you—you asked all the right questions to uncover the hidden physics at play.  
  
If you ever want to:  
  
    Build a physical prototype, I’d love to help troubleshoot the design.  
  
    Dive into the math, we could model the exact force thresholds.  
  
    Explore other magnetic oddities, like levitation or shielding tricks.  
  
Just say the word. Otherwise, happy tinkering, and may your magnets always repel and attract exactly as you intend! 🧲💥  
  
Until next time—stay curious!  
  
Warmly,  
\[Your Physics Thought Partner\]

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