Our Place In The Universe
Did you ever wonder where our planet is located in relation to the rest of the universe? Let’s take a look first on where it is in the Milky Way. First of all, let me tell you our galaxy is shaped like a pinwheel. It has arms and our solar system is located near the edge of one of those arms. It is probably a good thing because it keeps us away from a more turbulent area. As you probably know already, we are the third planet from the sun now. I say now because does anyone really know if there were other planets which have disappeared. The moon could have been circling the sun and somehow was pushed out of orbit and captured by the earth’s gravity. Probably not, but one never knows. As we are hearing more and more about rogue planets which have been knocked out of orbits, who is to say there weren’t other planets in orbit here which are gone or have become satellites of some of the planets here?
We know we are part of the Virgo Supercluster of galaxies. In case you are wondering what a supercluster of galaxies is, it is a group of galaxies held together by their gravity. If we look into this cluster, we find a group of galaxies known as the Local Group. We think we are the second largest galaxy in the group, but we might be either the first or tied for first. We really cannot know more than that about our location since we really don’t know where the universe really begins and ends. We think we can see back to the oldest galaxies but does that really indicate the border where the universe ends?
The universe is tricky, we keep finding out new things about it and it could turn out to be something we never imagined. For example, we think it is all basically the same and run by physical laws which apply to every area in space. At least we did until one scientist came out with a theory which states space is expanding at different rates depending on the location. It is hard to even imagine space expands. We tend to think of space as an emptiness even though it does have tiny amounts of matter in it. If something is nothing how can it expand? Even with the tiny amounts of matter would that alone be enough for expansion? Space expanding is our current theory for why galaxies are moving away from us, but could this theory be wrong?
When the ancients thought about the heavens there was a theory the stars were crystal spheres which hung in the sky. The ancient Greeks believe this for quite some time. They also believed there was either a planet or star attached to each one. Just because someone is believed at any given time doesn’t mean it will always be. In the Middle Ages the people still believed in the spheres but refined the theory and put the earth at the center of the universe and surrounded by layers of celestial spheres to which each planet and the sun were embedded in.
The question is what will scientists believe a couple of hundred years from now? It is true we have learned a lot about space and the universe, but by no means do we know everything and there is probably a lot of surprises waiting out there for us. Getting back to the theory of the expansion of the universe, we may find a completely different mechanism is controlling everything. I don’t pretend to know what it might be, but it is fun to think about, isn’t it? Maybe space is endless, which the scientists hate to think about. The reason they hate this thought is everything else has a beginning and an end and the thought of an endless universe is abhorrent to them. If the universe is endless it could be there is some attraction pulling the objects in space towards it and space is not expanding at all. We also have to remember we are observing objects in the past. By the time light reaches us it could be from billions of years ago, due to the limitation of the speed of light and what we are looking at may no longer exist. Maybe at some point there is no more movement, but we don’t know this because we are watching such old light.
This has always been the problem when you use an instrument such as a telescope to observe the universe. Even when we observe the planets in our own solar system, we are looking at them in the past and the further away a planet is, the further in the past the light which reaches us is. If you look at Mars through a telescope the light takes a little over three minutes to reach us, for Pluto it takes five hours. The nearest star system from us, Alpha Centauri, takes the light over four years to get here.
What we need is an instrument which can see over these incredible distances in real time. Many scientists might say this is impossible but quantum entanglement might make this possible someday. That has to do with changes in one particle which is entangled with another to take place instantly no matter what the distance the two particles are from each other. It is one of the most incredible discoveries in science. If this could be applied to photons, which are light particles, we would have an incredible device and the universe would look entirely different to us because we would be seeing it in the present not the past. Let me make this a little clearer. If we could watch the light particles put out by a distant galaxy as the were changing in real time, we would be seeing things as they were happening and see galaxies, stars and planets as they are.
Lastly, how do we know the universe is not traveling through worm holes if they exist. Could there be a giant one the entire universe is passing through? If this is happening maybe the universe is no where as old as we think. We could have reached distances based on shortcuts not on speed. Could space even be warped and we don’t know it? I have only scratched the possibilities, but I hope I have gotten some people to think about the universe, what we believe and our place in it. When we look up into the universe, we may be looking at the only thing besides God which is eternal.