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Gravity is a force of attraction that exists between any two masses, any two bodies, any two particles. Gravity is not just the attraction between objects and the Earth. It is an attraction that exists between all objects, everywhere in the universe. Sir Isaac Newton (1642 -- 1727) discovered that a force is required to change the speed or ...
A cluster of stars, dust, and gas held together by gravity. GAMMA-RAYS Penetrating short wave electromagnetic radiation of very high frequency. GEOSYNCHRONOUS An orbit in which a satellite's rate of revolution matches the Earth's rate of rotation. This allows the satellite to stay over the same site on the Earth's surface at all times.
3. Activity: Explain that the sheet represents spacetime, the large object represents the Sun and the smaller object represents a planet. Have the students pull the edges of the sheet outward. Make sure the sheet is taut. Roll the lighter balls across the sheet. Note how they travel in a straight line. Place the heavy object in the center of ...
Stars evolve, or change, over time. It may take millions of years or it may take billions of years for a star to complete its life cycle. A star is a brilliantly glowing sphere of hot gas whose energy is produced by an internal nuclear fusion process. Stars are contained in galaxies. A galaxy contains not only stars, but clouds of gas and dust.
纸面参数上，Gravity 配备了两个 40mm 的全频扬声器和 Rubber edge 双被动振膜，使用了 TI 的 数字功放；从实际听感来说，Gravity 的声音风格是比较中性的，三频比较均衡，以 Bose SoundLink Mini II 作为对比的话，Gravity 音染没有那么重，中低频量更少但更有弹性。. Gravity ...
Galileo designed a variety of scientific instruments. Among them was the hydrostatic balance. This was an instrument used to find the specific gravity of objects by weighing them in water. Go to Imagine the Universe! (A site for ages 14 and up.) The StarChild site is a service of the High Energy Astrophysics Science Archive Research Center ...
What makes the Sun shine? Answer: The simple answer is that deep inside the core of the Sun, enough protons can collide into each other with enough speed that they stick together to form a helium nucleus and generate a tremendous amount of energy at the same time. This process is called nuclear fusion.
Galaxies range from a few thousand to a million light-years in diameter. A galaxy is a cluster of stars, dust, and gas which is held together by gravity. Galaxies are scattered throughout the universe and they vary greatly in size. A galaxy may be alone or it may be in a large group of galaxies called a "supercluster".
It is in the clouds of dust and gas that stars are born. As more and more of the gas (which is mostly hydrogen) is pulled together by gravity into a cloud, the cloud starts to spin. The gas atoms start to bump into each other faster and faster. This creates heat energy. The cloud gets hotter and hotter. Finally, it gets so hot within the cloud ...
Black Holes. Some scientists believe that there is a black hole here in our very own Milky Way. Black holes are extremely compact space objects that were once massive stars which collapsed inward due to the force of their own gravity. Consequently, black holes are very dense. If it were not for the effect that black holes have on the objects ...
