Everyone knows that no two snowflakes are identical to one another. That's because they all start out as a simple hexagonal prism - the most basic form of snow crystal - but then encounter a range of atmospheric conditions as they journey down to Earth.
It was two Japanese physicists who made early strides in our understanding of snowflake formation. Ukichiro Nakaya at the University of Hokkaido in the 1930s and Takehiko Gonda in the 1970s at the Science University of Tokyo found that humidity, temperature, air pressure and other conditions are the variables that determine the shape of a snowflake.
Kenneth Libbrecht writes, “Although no two crystals end up exactly alike, the six arms of a single crystal all travel together, so they all grow in synchrony, giving each falling crystal a unique and intricate structure with a recognisable symmetry.”
The conditions in the atmosphere dictate how water molecules are transported to the crystal but, because of the infinitesimal range of conditions, that makes it hard to simulate snowflake growth and explain how particular structures are formed.
Numerical modelling is now being used to reproduce the complex structures. The work is of particular interest to metallurgists as a better understanding of snowflake structures could profoundly affect the strength and ductility of their own final materials on a micro- or even nano-scale.
Libbrecht continues, “Beyond the intrinsic scientific questions, beyond the practical applications of crystal growth, and beyond the meteorological significance of atmospheric ice, we who ponder snowflakes are motivated by a simple and essential desire to comprehend the natural world around us.”
Also in this issue:•Funding bombshell hits UK physics
Dianne Stilwell | alfa
Magnetic nano-imaging on a table top
20.04.2018 | Georg-August-Universität Göttingen
New record on squeezing light to one atom: Atomic Lego guides light below one nanometer
20.04.2018 | ICFO-The Institute of Photonic Sciences
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy