Space

The universe of within

In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move (Douglas Adams).

We come to the world as a lump of organic and fluid flesh, we see shapes and feel sensations of the world and try to piece them together with meaning – trying to ultimately become stronger, wiser and more resilient to the forces of the world and beyond. We know what our peers told us and go along with it, questioning the nature of reality on very seldom occasions. The lines of fact and fiction become blurred in our complex environment – owing to there being so much to understand, see and do, we have to make assumptions in order to function, and some of these assumptions may very well be wrong. But how will we ever know the difference between them. A good start would be discussion I suppose. Another would be inner exploration, and a third would be the exploration of the world out from ourselves.

The world is after all a very small and insignificant place in relation to the universe itself. To us, yes, it's very significant, even our lives as the universe continues on without acknowledging any of this. So let's put things into perspective.

The universe is quite large, rough estimates today predict the universe to be around 93 billion light years across. Now that's big. How do we know this, well, this is a figure which has taken centuries of research, understanding and data correlation to find out. It wasn't until recently that we understood the size of our own galaxy (100,000 – 150,000 light years across) let alone the scale of what was beyond. To discover how far an object in the nights sky is from us, we have a few techniques, most of them begin in our own solar system. We can use radio signals to bounce waves from the planets in our solar system and back again and time how long it takes. This gives us an accurate measurement array for the distances to our neighbours. Next, we can use something called parallax measurement. Like how we see the world with two eyes to build up a 3-dimensional picture, using a telescope we look at a nearby star and measure it in relation to the other objects in the sky, then 6 months later, we do it again. This enables us to calculate the shift and work out approximately how far away it is. For this measurement, around 100 light years is the extent of this technique, for any further and the differences on shift become too small. Following this we can use something called 'main sequence fitting'. It relies on our knowledge of how stars of a certain size evolve over time; from brightness to red shift. Red shifting indicates the movement that celestial body has relative to us. If it shifts to a red shift it is moving away from us, if it's blue shifted then it is moving towards us. Not only that, but comparing the age and relative size of these stars we can determine due to the light intensity and red shift comparatively how far they are from that object and work our way back to us. But again, this kind of technique runs into problems in accuracy over large distances, so way back in 1908, Swan Leavitt realised that there was a special class of stars called Cepheid variables. "She made this observation that a certain type of star varies its brightness over time, and the variation in the brightness, the pulsations of these stars, relates directly to how bright they are intrinsically," says Casey. In other words, a brighter Cepheid will "pulsate" more slowly (over the course of many days, in fact) than a dimmer Cepheid. Because astronomers can measure the pulse of a Cepheid relatively easily, they can predict how bright the star is. Then, by observing how bright it actually appears to us, they can calculate its distance.

There are also things called quasars, galaxy mapping, star counting etc to estimate the relative size of the universe. With all of these methods combined we gradually can determine the size of the universe with increasingly more accuracy.

So how small are we – the answer is 'very'.