Fourier Analysis
Fourier series A Fourier series is a way to represent a function as the sum of simple sine waves. A simple trigonometric function consists of a smooth surface. If you continue to add these trigonometric functions, … more
Formation Model of Columnar Joint
Formation of Columnar Joint A columnar joint appears as a polyhedral pillar, such as a tetragonal, pentagonal, or hexagonal shape. Its shape depends on the rate at which the lava solidifies. Columnar joints are often mistakenly … more
Differentiation
Differentiation The differentiation is to find the amount of change at a point on a graph f(x). This is like the process of finding the slope of the tangent line when you can draw a tangent … more
Stellar Parallax
Parallax When an object is close to me, you can use a ruler to measure the distance. But, it isn’t easy to measure when the object is away from me. In this case, how can you … more
Horizontal Coordinate System
Celestial coordinate system A celestial sphere is an abstract sphere centered on an observer. All objects in the sky can be conceived as projected upon the celestial sphere’s inner surface. Horizontal Coordinate System The horizontal Coordinate … more
Equatorial Coordinate System
Celestial coordinate system A celestial sphere is an abstract sphere centered on an observer. All objects in the sky can be conceived as projected upon the celestial sphere’s inner surface. Equatorial system The equatorial coordinate system … more
Constellations
Constellations If you look at the sky where there is no light on a clear night, there are so many stars that can not count. Thousands of years ago, the ancients linked stars to create constellations … more
Chemical Change of Candle
Paraffin, the main ingredient of candles Paraffin, the main ingredient of candles, is alkane hydrocarbons in which 20 to 40 carbon atoms are linked in a chain. It does not dissolve in water as a polar … more
Celestial Equator and the Ecliptic
The tilt relationship of the celestial sphere and ecliptic The celestial equator is the enlargement of the earth’s equator to the celestial sphere. Therefore, the celestial equator can be represented by a line fixed on the … more
Theo Jansen Mechanism
Theo Jansen He is the leading artist of kinetic art with the nickname of Da Vinci in the 21st century. He is famous for making wind-driven structures using simple materials such as PET bottles, tubes, and … more
Charles’s Law
Charle’s Law Assuming constant pressure, increasing the temperature of the gas will speed up the molecular motion. As the gas often collides with the vessel wall, the volume increases. Conversely, if you lower the temperature of … more