Held by Tension, Shaped by Light
Kyle DeLucia
Award: Top 100
School: sleepy hollow high school
Teacher: leila madani
Category: Contrived
Photo #21090
Held by Tension, Shaped by Light
This enrapturing photo was very simple to set up. It required a bowl of water, paperclips, and a screen.The floating paperclip works because of surface tension, which primarily arises from hydrogen bonding. These are the electrical attractions between the hydrogen atoms of one water molecule and the oxygen atoms of another. At the surface, water molecules cannot form hydrogen bonds above them with the air, so they create stronger bonds with their neighbors below and to the sides. This creates a tightly knit "molecular skin" that is strong enough to support the weight of an entire steel paperclip, despite steel being much denser than water.
This phenomenon also reveals that gravity is actually the weakest of the fundamental forces. The electromagnetic attractions that drive hydrogen bonds are so comparatively powerful that a simple network of molecular bonds can counter the gravitational pull on a metal paperclip. When the paperclip is placed gently onto the surface, the downward force of gravity is balanced out by the electrical attractions at the molecular level.
The photo also demonstrates principles of geometric optics. The paperclip creates a slight depression in the water surface, curving it into a shape that functions like a miniature lens. As light passes through the curved surface, it refracts and bends while moving from one medium to the next. A consequence of refraction is reflection off the transparent water surface. These reflections highlight the depth of curvature of the water surface beneath the paperclips.
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