Beautiful Butterfly: The Physics Behind The Colors
Even as a child, I was fascinated by the colors in nature, such as rainbows, butterflies and flowers. This fascination developed into curiosity with age, and as my school studies developed, I became particularly interested in the scientific aspects of the origin and development of colors. I wanted to answer the question: How are the different colors of the butterfly wings related to the nanostructures of scales and pigments? The color on the butterfly wings results either from the pigmentation (chemical color) or from the structure (physical color) of the wing scales. Colors such as yellow, black, red and brown are mainly created by pigments. The interaction of light and structures in and on the surface of butterfly wings, often the size of the wavelength of the light, results in physical colors. These colors are usually bright and dependent on the viewing angle (unlike chemical pigments that spread light diffusely). The colors produced here are usually golden, green, purple and blue. But, where do these colors come from and why do certain species dazzle more than others? To get to the heart of the matter, I identified two key questions: • How are the different colors of the butterfly wings related to the nanostructures of scales and to the pigments? • Using the nanostructure, can you find out the wavelength of the reflected light? In this work, I focus on the structural colors of butterflies and study the physics behind them. This includes parachuting in areas such as diffraction gratings, scattering of light, interference in thin films, and multilayer interference. In order to experience the greatest possible diversity, I selected butterflies from different species for the measurements. Using the spectrometer, I measured the light reflected from butterflies. High-resolution microscopes such as the laser microscope and the scanning electron microscope gave me the opportunity to study the detailed nanostructures of the wing. In addition, I was able to analyze and evaluate my results using existing physical models and MATLAB simulations (Maxwell equations).
The expansion of ticks in the valley of Poschiavo: a growing threat to the future?
In recent years, the ticks have reached the valley of Poschiavo and so far no study has been done to determine their diffusion. Recently, this presence has become a much discussed topic as these ticks can be carriers of pathogenes and represent a danger to humans. The goal of this work is to analyze the current situation in the valley of Poschiavo to understand in which areas the ticks are widespread, if they are carriers of pathogens and which factors could have an influence on their expansion. Several methods have been used for data collection. Ticks were found on ungulates killed during the high hunt in autumn 2016. In spring 2017, ticks were collected in various areas of the valley using the flag method that involves dragging a cotton cloth onto the ground. Some of the collected ticks were sent to a laboratory to identify the presence of the Borrelia burgdorferi, the pathogen responsible for Lyme borreliosis. To understand the evolution of the presence of ticks in the valley, the doctors and veterinarians were interviewed. Finally, to identify any climate changes related to the diffusion of ticks, the evolution of the tem-perature and relative humidity measured by two meteorological stations in the valley of Poschiavo since 1980 have been analyzed. Thanks to this study it was possible to highlight for the first time the presence in the valley of Poschiavo of ticks wich are bearer of the Borrelia burgdorferi. In fact, the bacterium was present in 26% of the analyzed ticks. Currently, the thicks populate the southern part of the valley, from the lake of Poschiavo to Campocologno, a small area in the central part of the valley and the area around Poschiavo and San Carlo. The interviews carried out showed that in recent years the ticks in the valley have increased and that the climate change could be a possible cause. In fact, since 1980 the temperature measured on the bottom of the valley has increased on average by 1.5 ° C and also the relative humidity has risen slightly. These changes could affect the diffusion of ticks in the valley of Poschiavo. In the future the temperatures will rise further and consequently the climate of the Poschiavo valley will most likely be more suited to the life of the ticks favoring their in-crease.
Effect of Air Resonance by Wind Speed Difference on Falling fruit
This study completes an air vibration equation expressed wind speed slope and wind speed. First, preliminary experiments identified air vibrations when wind speed differences occurred over distance. Several air fans were connected in series and the rotational speed of the air fan was adjusted to vary the wind speed with distance. At this time, only certain pendulum oscillates during a particular wind speed slope. It was expected that the pendulum would shake because the frequency of the air due to the slope of the wind speed was equal to the natural frequency of the pendulum. In addition, relatively short pendulum swings in large wind speed slope, long pendulum swings in short wind speed slope. After calculating the natural frequency of the seasonal growth of fruit using the physical factors model, we experiment how resonant frequency was related with cone length, angular width, wind speed, velocity and secondary derivative. the actual experiment analyzed the natural frequency of the fruit and resonance from the air vibration as the linear function of the wind speed, velocity, and secondary derivative. The experiment determined that the pendulum of a specified number of frequencies resonated with a particular wind speed pattern. It is judged that the vibration of air is related to first derivative of wind speed depending on speed and distance. However, it is very difficult to express the flow of nonlinear fluids as a function of simple function, particularly the effects of air vibrations caused by wind speed second derivative, which appeared to be associated with forces. This is a task that needs to be solved through further research.