When Heat Defeats Magnetism

A paper clip hangs in midair, seemingly defying gravity.

A magnet pulls it upward while a thread pulls it downward. The forces balance, creating a delicate equilibrium.

Now comes the challenge:

Can heat destroy the magnetic attraction and make the paper clip fall?

What You Will Observe

A ring magnet is suspended with its symmetry axis vertical.

A paper clip is tied to a thread so that:

• Gravity pulls it downward
• Magnetic attraction pulls it upward
• The clip remains suspended without touching the magnet

The paper clip appears to float in space.

Prediction

Most magnetic materials lose their magnetic behaviour when heated sufficiently.

This happens at a characteristic temperature called the Curie temperature.

Below the Curie temperature:

• Atomic magnetic moments tend to align.
• Magnetic order dominates.

Above the Curie temperature:

• Thermal agitation disrupts alignment.
• Disorder dominates.
• Ferromagnetism disappears.

The transition is one of the most important phase transitions in physics.

Physics

The competition is between magnetic interactions and thermal motion.

At low temperature:

• Magnetic order wins.

At high temperature:

• Thermal disorder wins.

The critical temperature is called the Curie temperature. Above this temperature, a ferromagnetic material becomes only weakly magnetic.

Attempt 1: Electrical Heating

The paper clip was bent so that a battery could be connected across it using crocodile clips.

Current flowed through the metal.

The expectation was simple:

1. Current produces heating.
2. Temperature rises.
3. Magnetic attraction weakens.
4. The clip falls.

But something unexpected happened.

The clip became warm, yet remained suspended.

Perhaps the temperature never approached the Curie temperature.

Or perhaps something more subtle was occurring.

Attempt 2: Candle Heating

The next step was more direct.

A candle flame was used to heat the paper clip.

The clip became much hotter than before.

Again the prediction was clear:

Heat the clip enough, remove its magnetism, and it should fall.

But it still did not fall.

The result raises new questions.

Mystery

Why did the clip remain attached?

Several possibilities exist:

Possibility 1

The clip never reached its Curie temperature.

Many steels have Curie temperatures of several hundred degrees Celsius.

A candle flame may not have heated the entire clip sufficiently.

Possibility 2

Only part of the clip became hot.

The cooler sections may have remained magnetic.

Possibility 3

The magnetic field from the ring magnet may still induce magnetization in the cooler regions.

Possibility 4

The material of the paper clip may not behave exactly as expected under heating.

Possibility 5

The Curie temperature may have been reached only briefly and locally.

Your Challenge

This experiment is intentionally left unfinished.

Can you make the clip fall?

Possible approaches include:

• Using a butane torch
• Using a propane flame
• Measuring temperature directly
• Trying different magnetic materials
• Testing different paper clips
• Using stronger magnets
• Recording the experiment in slow motion

The goal is not simply to reproduce a known result.

The goal is to investigate why the expected result did not occur.

This experiment connects several deep ideas: