Author Archives: Yihao Yan

String theory – the other way of interpreting our universe

Posted on April 27, 2019 by Yihao Yan

The string theory is a very interesting idea that propose another totally different way of thinking what made up our universe. Although this theory is very arguable because it can never be tested in our labs so that a lot of physicist do not like this theory, but it indeed gives a very unique prospective … Continue reading String theory – the other way of interpreting our universe → Continue reading →

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Introduction to various spacecraft propulsion methods

Posted on April 27, 2019 by Yihao Yan

Space propulsion is different from regular propulsion methods that deal with situations on the ground or in the air. It’s also different from launch propulsion which space propulsion methods exclusively deal with propulsion systems used in vacuum of space. Before introducing different propulsion methods, there are couple of concepts that are really important related to … Continue reading Introduction to various spacecraft propulsion methods → Continue reading →

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Extrasolar planets — Earth-like planets

Posted on April 7, 2019 by Yihao Yan

Extrasolar planets is one of the most interesting astronomical research topics. It can help us answer questions such as whether there are aliens, or is it possible for us to find another “Earth” to live on. An extrasolar planet is defined as a planet that is outside of solar system. The history of extrasolar planet … Continue reading Extrasolar planets — Earth-like planets → Continue reading →

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The Mysterious Black Hole

Posted on March 12, 2019 by Yihao Yan

The black hole is one of the most amazing and mysterious object in our universe. In 1916, Karl Schwarzschild first provided the solution to general relativity that characterize a black hole. Black hole is the remnant of super massive star’s explosion, and it has such a strong gravitational pull that nothing can escape, not even … Continue reading The Mysterious Black Hole → Continue reading →

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Composition of Solar System

Posted on March 12, 2019 by Yihao Yan

The solar system is a planetary system consisted of star Sun, planets, comets and other objects orbiting around the Sun, and Earth is one of them. The major mass of solar system is from the Sun. The sun is a G2 main-sequence star at the center of solar system which contains about 99.86% of total … Continue reading Composition of Solar System → Continue reading →

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The window of universe — Various types of Telescope

Posted on February 10, 2019 by Yihao Yan

The science of astronomy is about the telescopes. Without them, our naked eyes can only see thousands of stars in the night sky away from city lights. We get to see galaxies, stars, nebulas and other celestial objects that are light years away from us through telescopes. Furthermore, as the technology improved over the last … Continue reading The window of universe — Various types of Telescope → Continue reading →

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Historical Astronomers in Context – Johannes Kepler

Posted on January 26, 2019 by Yihao Yan

Johannes Kepler. (Dec.27.1571 – Nov.15.1630) He was important to astronomy for his revolutionary discovery of laws of planetary motion, and his books Astronomia nova, Harmonices Mundi, and Epitome Astronomiae Copernicanae. His laws of planetary motion describe how planets orbit around the Sun and the relationship between their period and their orbit length. His works contribute to Newton’s theory … Continue reading Historical Astronomers in Context – Johannes Kepler → Continue reading →

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Picture the enormous universe

Posted on January 20, 2019 by Yihao Yan

The vast size of universe is so hard to picture in one image because its size is unbelievably enormous compared to human and Earth. Our planet Earth has the size around 12,742 km diameter. And the nearest object to us is moon which is approximately 384,400 km from us. The number is already huge in … Continue reading Picture the enormous universe → Continue reading →

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