SCIENCE

Ants, Raisins, and Quarters

by Alex Hutchins

Imagine yourself as an ant walking along the 2 dimensional surface of a balloon that is starting to inflate.  As you walk, you hardly notice the inflation but if you did, you might wonder:  Into what is it inflating?  All you know are the dimensions of length and width, light and dark.  But, your balloon is inflating into a third dimension: of depth.  As long as you remain as an ant in your 2-dimensional world, you will never know or experience anything else.

Now, imagine yourself as you really are, a human being, walking along the street of your city in a 4-dimensional world:  length, width, depth, and time; and, someone tells you that your world, your universe is expanding; but, before you can process that thought they tell you that your universe is not really expanding, it is the distance between the planets is increasing like the raisins in cookie dough being cooked in the oven:  the raisins don’t expand, it is the dough between the raisins that is expanding as the dough is being cooked.

Now, if you can, apply both these ideas (ants and raisins) to our ever expanding universe . . . 

Somewhat mind boggling, is it not?

But, before going further, let’s break it down.

The earth is in a Solar System which is in a Galaxy (along with billions of other Galaxies) that is in the Universe, which is continuing to expand as if it were a balloon or a cookie.

Solar System: Consists of the Sun, and everything bound to it by gravity. This includes the 8 planets and their moons, the asteroids, the dwarf planets, all the Kuiper [sic] belt objects, the meteoroids, comets and interplanetary dust.

Galaxy: large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space. The Milky Way measures about 100,000 light-years across, and is thought to contain 200 billion stars.

Universe: the totality of known or supposed objects and phenomena throughout space; the cosmos; macrocosm.

So, to sum it up:

1. We live on planet Earth which is part of our local Solar System.
2. Our Solar System includes the Sun and everything that orbits the Sun.
3. Our Sun, is just one Star in the Milky Way Galaxy.
4. The Milky Way Galaxy is just one Galaxy in the Universe.

Leaving Our Solar System

NASA's Voyager 1 spacecraft has encountered a new environment more than 11 billion miles from Earth, suggesting that the venerable probe is on the edge of leaving our  solar system (see image below).

The Voyager 1 probe has entered a region of space with a markedly higher flow of charged particles from beyond our solar system, researchers said. Mission scientists suspect this increased flow indicates that the spacecraft — currently 11.1 billion miles (17.8 billion kilometers) from its home planet — may be poised to cross the boundary into interstellar space.

"The laws of physics say that someday Voyager will become the first human-made object to enter interstellar space, but we still do not know exactly when that someday will be," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena, in a statement.  "The latest data indicate that we are clearly in a new region where things are changing more quickly," Stone added. "It is very exciting. We are approaching the solar system's frontier."            Read more

Remember the Star Trek movie where the crew of the Enterprise
encountered the Voyager probe?

How big is our universe?

Well, imagine our solar system as a quarter inside our Galaxy which is referred to as the Milky Way Galaxy.  The nearest star (and hence nearest solar system) is 2 football fields away.  And, it took the Voyager 1 Probe over 30 years of traveling in space to get to close to the edge of our Solar System.