Lying on a Bed of Nails

The bed of nails demonstrates how spreading force over a large surface area reduces pressure. A person can safely lie on many nails without injury because the force of their weight is divided among the nails.

Bed of Nails - Harvard Natural Sciences Lecture Demonstrations:

Human Bed of Nails - Cool Science Experiment - SpanglerScienceTV:

📄 How to Make a Bed of Nails - Science Demonstration - Beals Science: https://www.bealsscience.com/post/how-to-make-a-bed-of-nails-science-demonstration

• Place a board on the chest and gently rest a cinder block on top (only under professional supervision).
• Show the same principle using balloons pressed against one nail versus many nails.

• Only use a bed with many closely spaced nails; never attempt with a small number of nails.
• Do not allow unsupervised students to attempt lying on the bed.
• Keep demonstrations simple and avoid risky add-ons like hammers unless performed by trained professionals.
• Ensure nails are smooth, clean, and securely fixed to avoid cuts or punctures.

• Why doesn’t lying on many nails cause injury? (Because the force is spread out over many points, reducing pressure at each point.)
• What would happen if only a few nails were used? (The pressure would be high enough to puncture the skin.)
• How does this relate to walking on snow with snowshoes? (Snowshoes spread weight over a larger area, reducing pressure so you don’t sink.)