How Big may be the Universe
How big is the universe? This may be the central question that I try to answer in this article, based on current research in observational astronomy. Though this question seems quite plain and simple, the answer to it is definitely not. Let us see why it is so.
Our globe is a small dot inside the vastness of space, revolving about yet another brighter and larger dot, the Sun, which revolves around the galactic center of the Milky way galaxy. Our galaxy is one of the billions of galaxies that exist inside the Universe! These galaxies form clusters and clusters form super galactic clusters. The scale of complexity keeps on growing to gigantic proportions. It has no end perhaps.
Universe is the totality of space, time, matter and energy. It includes every physical entity that exists. Being a part of the universe, it is difficult to understand how big it really is! Trying to answer the question of how big is the universe, is questioning if the vast expanses of space and time have an edge or an end. Where does it finish? Does it keep going on and on (infinite) or does it have a finite boundary? Let us try to find an answer to this question. Universe size comparison cannot be made with anything else, as it encompasses everything!
There was a time when people had no concept about how big our planet Earth was. Men and women debated about what shape it was and whether it had an edge. To put an end to these questions, adventurers like Magellan underwent sea voyages and circumnavigated across the excellent oceans, to finally see for themselves. However, attempting to answer the question of how big will be the universe, will not yield a solution via a human voyage! The distances are gargantuan and billions of generations would have been born and died even just before one would get halfway across to the nearest galaxy. The reason is that our spacecrafts are not fast enough for exploration of the universe. So, we try to measure the expanses of the universe indirectly by means of the fastest traveling entity, which is light! Read much more on space exploration.
How Big is the Universe in Light Years?
There is no way we can understand how big will be the universe, unless we have a way of measuring huge distances and observing the farthest known objects. Light will be the fastest way of transferring information within the Universe. Actually, the speed of light (roughly 3 x 108 m/s) is unattainable for any physical object. Read a lot more on how does light travel.
The unit of measurement used to determine the distance of far away objects inside the universe is a ‘Light Year’. A light year may be the distance that a ray of light would travel unobstructed in 1 year! 1 light year is roughly 9.46 trillion kilometers! (Trillion is a thousand billion or 1 followed by 12 zeroes following it). The nearest galaxy to our own galaxy, the Andromeda is about two,500,000 light years. Light from the Andromeda would travel two.5 million years ahead of it would reach us! So, all that we see may be the past, as light takes a lot of time to reach us.
So, the only way 1 can know how big will be the universe, can be via observing light from as far as we can. The Hubble space telescope may be the eye that can see the farthest for us and what it sees are things that happened long ago! Which is because, light reaching us started traveling from there millions or billions of years ago. Just being able to observe light from afar is not enough, one needs some way in which we can estimate the distance from where it started. This is achieved via the use of cosmic candles, that are objects for which astronomers have a calibrated relation between distance and brightness. Using such cosmic candles, the farthest reaches of our universe have been explored. Still, 1 cannot say how big will be the universe but 1 can safely say that the observable universe extends for 93 billion light years! It is a number up to which you could not be able to count in a life time!
Read much more on: Amazing Facts About the UniverseHow was the Universe CreatedHubble Telescope FactsWhat lies beyond that observable horizon? There is no way we can know that currently, as light from farther has not yet reached us. According the prevalent theory of origin of the universe, the big bang theory, space time is expanding constantly and at an accelerated rate. The quite space-time, which will be the fabric of the universe, is expanding. So, we have no thought about how big will be the universe nowadays. Neither can we say anything about whether it’s finite or infinite. Whatever theories you hear about universe are all pure speculations. Only thing that can be stated is that it’s really really big and getting bigger by every passing second. Bigger than anything you can think of and full of surprises yet to be found!