At Beam Bridge, visitors experience how the thickness of a beam relates to its stiffness by cwalking across a beam laid on its edge and on the same beam laid flat. Walking on the beam both compresses and stretches the beam: there is compression in the wood fibers along the top of the beam and tension in the fibers along the bottom. On its edge, the beam has twice as many fibers resisting the forces that make it sag. However, it has half the fibers to resist bending from side to side. Lying flat, the beam has just the opposite qualities: it has half the fibers resisting the forces that cause it to sag, and twice the resistance to sideways bending.