Bigger Than You Can Imagine

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It is tough for the average person to get a proper grasp of the size of things in the universe.  To help us, scientists often use analogies.  For example, if the sun were an orange, the earth would be a grain of sand thirty feet away.

On a map of the universe the size of a city block, our solar system would be too small to appear.  A period at the end of a sentence would be fifty thousand times too large to represent the entire solar system.  If our Milky Way galaxy were the size of a dime, the universe would be something like a cloud of dimes four miles in radius.

Once we get outside the Solar system we have to start using a larger unit.  We use the light year, the distance that light travels in a year, about 5.9 trillion miles.  Yet compared to the Universe as a whole, the light year is a small unit of measurement.

The nearest galaxy to ours, the Andromeda galaxy, is 2.2 million light years away.  Beyond that the numbers are so large that astronomers use a unit called the ‘parsec', equal to 3.26 light years.  Soon they have to measure in million parsec units.  And when they deal with the most distant objects known, the quasars, they talk about objects 14 billion light years away, a distance that is inconceivable to most people.

So next time you are asked how big the universe is, just say, ‘it's bigger than you can imagine!'