Friday, April 18, 2008

Galaxies

Elish, Dan. Galaxies. Marshall Cavendish Benchmark: 2007. ISBN: 9780761420477.

Scientists believe in the Big Bang theory. The Big Bang theory presents that there was a giant flash and all the matter and energy came into being. For many years, scientists believed that there was only one galaxy, until recent research. In space, there are billions of galaxies but only three of them can be seen with the naked eye. Galaxies are so large that miles and kilometers are not big enough to measure them. Scientists use light years to measure galaxies. Light years move very fast, at a speed of 186,000 miles per second. A spiral galaxy is liike our Milky Way. It is a collection of stars with a bulge at the center. Last, are the quasars. Quasars are so bright that they have the light of a trillion suns. Black holes power them. Black holes suck almost anything into them and don't let it out.
The pictures are very interesting because you know some of them are taken from space. Also, you learn about what we have never seen.

Reviewed by B.T., Van Buren 7th Grade

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