Cracking an Egg Underwater

Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★★★ Requires a more experienced teacher
Safety: ★★★ Only to be attempted with adequate safety procedures and trained staff

Categories: Density and Buoyancy, Pressure and Fluids, Food Science and Nutrition

Alternative titles: Underwater Egg Pressure Experiment

Summary

When a raw egg is cracked open underwater at depth, the water pressure holds the egg white and yolk together in a jelly-like sphere. It resembles a floating sea creature and demonstrates how pressure and buoyancy act on fluids without a shell.

Procedure

Take a raw egg while scuba diving or during a controlled underwater demonstration.
Crack the egg shell open at depth (such as 60 feet underwater).
Observe how the egg white and yolk remain together in a floating mass instead of dispersing.
Move your hand or finger near the egg to see how it behaves like a jellyfish in water.
Optionally, clap hands or disturb the egg to see it break apart into pieces.

Links

What Happens When You Crack An Egg Underwater? - LiveScience:

📄 What Happens When You Crack an Egg Underwater? - Nerdist: https://nerdist.com/article/cracking-eggs-underwater-bermuda-institute-ocean-sciences/

Variations

Perform the demonstration at different depths to compare how water pressure affects the egg’s shape.
Recreate a similar effect in a microgravity environment (as teachers have done on parabolic flights).
Compare the behavior of an egg cracked in freshwater vs. saltwater.

Safety Precautions

Only attempt this experiment under proper scuba diving supervision and training.
Do not attempt with raw eggs in public swimming pools (risk of contamination).
Ensure eggs are disposed of properly to avoid environmental impacts.
Avoid sharp shell fragments while cracking the egg.

Questions to Consider

Why doesn’t the egg white and yolk disperse immediately in the water? (Water pressure at depth keeps the parts of the egg together, like an invisible shell.)
How is this effect similar to jellyfish floating in the ocean? (Both are soft-bodied and maintained by water pressure.)
What would happen if you cracked the egg at the surface instead of underwater? (The egg contents would disperse quickly into the water.)
How does this compare to cracking an egg in microgravity? (In both cases, the egg floats together in a sphere because there is no gravity pulling it apart into a flat shape.)