Lewis Carroll had no idea just how prescient his concept of seeing the world afresh through a looking glass would become in modern times. Alice peering back into Wonderland is nothing on you and I looking at the universe through the eyes of the Hubble Space Telescope.
Projects like the Sloan Digital Sky Survey have attempted to put this vast universe in perspective for us and yet, in reality, the size is incomprehensible. Every youtube video you’ve ever seen showing the size of the universe is deceiving in that the viewpoint moves with a logarithmic scale. Our minds work really well with linear scales where 30 is simply 10 more than 20 and a mere 10 less than 40. Logarithmic scales, like the Richter scale for earthquakes or the measurment of sound in decibels, are misleading in that they appear to move numerically when, in reality, each step-increase, from 4 to 5 or from 5 to 6, represents anywhere from double to ten times the impact of the previous number, increasing exponentially in a tangent. In the case of our beautifully illustrated flight from the Earth out through our solar system, through the Milky Way, out to the Local Galaxies and then into the network of galactic super clusters that make up the visible universe, we are, theoretically, “moving” trillions of times the speed of light as we accomplishing in minutes a journey that has taken light billions of years.
As wonderful a journey as that would be, it lulls us into a false sense of scale. Don’t get me wrong, I love those fly-bys, but they sure make the universe look pedestrian.
The Smithsonian’s National Air and Space Museum has helped put things in perspective with a blog post called Mapping Everything.
Here’s a representation of the local group of galaxies surrounding the Milky Way. Here in the Southern Hemisphere we can see the LMC & SMC quite clearly, the Large & Small Magellan Cloud. Although Andromeda has over two hundred billion stars it appears like a single, smudged star to the naked eye.
When we go out in the countryside and look up at a pitch black night sky, we see a mere five thousand stars from within these “local” galaxies, that’s less than 0.0001% of all those “local” stars.
Lets put the local group of galaxies in perspective. Take a good, long look at the single dot in the middle of the next image. The tiny one, right at the centre. That’s the entire local group, some six to seven billion stars.
Everything beyond that one single dot is a web of billions of galaxies, each comprised of billions of stars. Notice the thin bubble like filaments that appear on these scales, as tens of thousands of galaxies spread out to form super clusters.
As remarkable as this is, you’re not looking at an image of what the universe looks like, you’re looking at an image of what the universe once looked like billions of years ago.
Imagine, if you will, what life would be like if this same quirk of nature played out on Earth. Imagine if you stood atop the Empire State Building with a telescope that, defying the curvature of the Earth, could view any point on the planet. Only the catch is, when you look through your telescope, you see the world as it was, not as it actually is…
Stay with me here… if the world could be viewed on a scale just a fraction of what we’re looking at here, spanning thousands instead of billions of light years, then you’d look across at England and see the industrial revolution unfolding before you. You’d turn your telescope to France and see the Reformation of the 1500s overturning feudal values. Looking at Germany, you’d see hordes of barbarians fighting Roman soldiers. Looking down toward Greece you might catch sight of Socrates and Plato, while viewing further a field, across the Mediterranean sea, you may even catch a glimpse of an aging prophet carrying tablets of stone down the side of Mt Sinai. Looking into Egypt, you’d see the foundations of the pyramids being formed, just square slabs on which a few stones had been laid. Adjust your focal point and look deep into Africa and you may even catch a glimpse of Neanderthals walking out on the Savannah.
In essence, this is what we’re seeing when we look into the heavens at these kind of distances. In fact, in the image above, the only life on Earth at the one billion year mark was bacteria and, perhaps, some basic micro-organisms!
Look at the ring for 5 billion years. That’s what the universe looked like when the Earth was first formed from a vast cloud of dust and debris surrounding a young, brightly burning star, our Sun.
It’s tempting to look at our position as being in the centre of the universe, but that’s an illusion caused by our past light cone. If, as an example, another intelligence species, located some 12 billion light years away from us, was looking out toward the Milky Way, what would they see? We’ll, they’d see the reverse of what we see. They’d see their local galaxies highly defined and “we” would appear billions of years in the past, looking much like the far reaches of our current view. Mind bending, I know.
Although we can see some 12.7 billion light years into space, we don’t see 12.7 billion light years worth of space, we see 12.7 billion light years worth of space-time as it has evolved since the Big Bang. We see a luminous cosmic fossil record of the past.
Lewis Carroll… Eat your heart out…