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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 ...
An invisible object in outer space formed when a massive star collapses from its own gravity. A black hole has such a strong pull of gravity that not even light can escape from it. BLUR To make less clear, to run together. BIG BANG THEORY A theory that says the universe began with a super-powerful explosion. BOLT A flash of lightning. BOULDER
The Capture Theory: This theory proposes that the Moon was formed somewhere else in the solar system, and was later captured by the gravitational field of the Earth. The Moon's different chemical composition could be explained if it formed elsewhere in the solar system, however, capture into the Moon's present orbit is very improbable.
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. These clouds are called nebulae, and it is in a nebula where stars are born. In the nebula is hydrogen gas which is pulled together by ...
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.
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 ...
Dark matter is composed of particles that do not absorb, reflect, or emit light, so they cannot be detected by observing electromagnetic radiation. Dark matter is material that cannot be seen directly. We know that dark matter exists because of the effect it has on objects that we can observe directly. Scientists study dark matter by looking at ...
Gravity then pulled in more matter from areas of lower density and the clumps grew. After about 200 million years of this clumping, there was enough matter in one place that the temperature got high enough for nuclear fusion to begin - providing the engine for stars to glow.
