vanish into thin air
to disappear without leaving a trace
The university student vanished into thin air and was never seen again.
Science Experiments Ideas
Place two porcelain egg cups one in front of the other, with an egg in the front one. Blow hard from above on to the edge of the filled cup. Suddenly the egg rises, turns upside down and falls into the empty cup. Because the egg shell is rough, it does nor lie flat against the smooth wall of the egg cup. Air is blown through the gap into the space under the egg, where it becomes compressed. When the pressure of the cushion is great enough, it lifts the egg upwards.