- Why can't an ordinary microscope see particles smaller than the wavelength of visible light?
- How did Zsigmondy's ultramicroscope let him detect particles too small to be resolved directly?
- What longstanding scientific debate did Zsigmondy's observations of Brownian motion help settle?
Colloids and Soft Matter
The physics of gels, foams, polymers, and other soft materials.
- Why did chemists before Svedberg struggle to determine whether proteins were discrete molecules or fuzzy colloidal clouds?
- What did Langmuir discover about how molecules arrange themselves in single layers on a surface?
- What distinguishes a macromolecule held together by covalent bonds from a colloid held together by secondary forces?
- How did the acceptance of macromolecule theory make possible the modern plastics and synthetic fiber industries?
- How did de Gennes adapt the mathematics of magnetism to describe liquid crystals and polymers?
- What everyday technologies trace their design principles back to de Gennes's soft matter programme?
- How much faster does damp fabric conduct heat away from the body compared to dry fabric?
- What structural mechanics determine the moment a puffed cereal grain loses its crunch in milk?
- What struck Columbia's wing at launch, and why had it not been treated as a serious risk before?
- How do the hips and the hoop exchange momentum to keep the hoop spinning?
- Why did children solve this physics problem empirically decades before scientists modeled it?
- Why did male jewel beetles try to mate with discarded beer bottles instead of female beetles?
- How did the Australian government respond to the discovery?
- Why does the statistical curliness of individual hair fibres matter for predicting overall ponytail geometry?
- Why do wombats produce cube-shaped droppings instead of the round pellets other animals produce?
- How do spiders extend their legs without extensor muscles, and why does this cause dead spiders to curl up?
- How did Te Faye Yap's team turn a dead spider into a functioning robotic gripper?
- How can a solid material have an internal surface area exceeding 7,000 square metres per gram?
- How did Tomoki Kojima test whether zebra-like stripes reduce biting fly attacks, and on what animals?
- How much did painting cattle with black-and-white stripes reduce fly attacks compared to unpainted controls?
- What hypotheses have been proposed for why high-contrast stripe patterns disrupt biting flies' vision?
- What features of glasswing butterfly and Cicada wing nanostructures are being mimicked to achieve omnidirectional antireflection on fused silica?
- How do these self-assembled isotropic structures differ from the ordered branching architecture of butterfly wing-scale lamellae, and what does that mean for coating applications?
- How does block copolymer self-assembly during polymer processing produce the periodic nanostructures responsible for structural color in 3D-printed parts?
- Why does increasing the molecular weight of a block copolymer shift the reflected structural color toward longer (redder) wavelengths?
- What makes lamellar morphology from roughly equal-volume diblock copolymers analogous to the layered nanostructures found in butterfly wing scales?
- What advantages does a block copolymer self-assembly route offer over lithography for manufacturing structurally colored plastic parts at scale?
- Why does faithfully replicating butterfly wing scale optics require hierarchical nanostructures rather than a single length scale?
- How does template-directed self-assembly using real butterfly wings as sacrificial templates preserve the ridge-lamellae hierarchy in the final inorganic replica?
- How does loading a Bragg reflector with beta-carotene pigment reduce the number of layers needed to reach high reflectance compared to a pigment-free structure?
- Why can pigment absorption inside a photonic structure boost reflectance at wavelengths that lie outside the pigment's own absorption band?
- How does combining pigment with nanostructure suppress iridescence and expand the achievable gamut of non-iridescent colors, as seen in butterfly coloration?
- How can hierarchical micro- and nano-scale laser patterning replicate biological functions such as structural color, superhydrophobicity, and antibacterial surfaces?