Spider silk
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Spider silk is a protein fibre or silk spun by spiders. Spiders use silk to make webs or other structures that function as adhesive traps to catch prey, to entangle and restrain prey before biting, to transmit tactile information, or as nests or cocoons to protect their offspring. They can use the silk to suspend themselves from height, to float through the air, or to glide away from predators. Most spiders vary the thickness and adhesiveness of their silk according to its use.
A female specimen of Argiope bruennichi wraps her prey in silk.
Indian Summer by Józef Chełmoński (1875, National Museum in Warsaw) depicts a peasant woman with a thread of gossamer in her hand.
Spider cocoon
An illustration of the differences between toughness, stiffness and strength
N-slit interferometer
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The N-slit interferometer is an extension of the double-slit interferometer also known as Young's double-slit interferometer. One of the first known uses of N-slit arrays in optics was illustrated by Newton. In the first part of the twentieth century, Michelson described various cases of N-slit diffraction.
The diffraction pattern over the interferogram shown above, corresponding to N = 3 slits, was generated using a single spider silk fiber with a diameter of about 25 μm.