A look at the stars presentation


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A look at the stars presentation

  1. 1. The universe was born in 1960, or so it seemed to me at the time. From where I stood, in my cot in my first ever bedroom, the universe consisted of blankets and soft toys and faces that sometimes sang nursery rhymes. Albert Einstein said the universe would expand, and so it did to include a house and a driveway and people who inhabited a school and a neighbourhood. It has been expanding at a fairly constant rate ever since.<br />
  2. 2. The universe and I were perhaps ten years old when my older brother took me out into the driveway one night to look at the stars. Now, I had certainly seen stars before in my life, but as far as I can remember this was the first time I actually looked at stars. Stars were insignificant. I cared as little about stars as I cared about the patterns on my bedroom wallpaper or the lint on my school uniform. Stars didn’t move. Stars didn’t talk. Stars didn’t do anything to intrude upon my busy mental life, so why should I or anybody else want to look at them?<br />
  3. 3. Well, I looked. I looked because my brother was fifteen years old at the time and knew everything about science, and if he asked me to look at the stars, well, it was somehow cool to do so. So I looked. The stars didn’t do a damn thing. But while I was looking, my brother began to tell me about them. Rigel, he said, was a blue star. He pointed it out; the bright star above the three stars that make Orion’s Belt. I didn’t know that stars had colours, so I had to stare at it for quite a while to convince myself that indeed it was a wee bit bluer than plain white. <br />
  4. 4. But it was interesting to suddenly discover that stars were as individual as people. They had names and they had colour. Another star, he said, was called Betelgeuse and it was a red giant. It didn’t look very big to me, but I can confirm that the star had a faint red tinge to its glow. He went on to label other stars and tell me the things that made each of them special. Alpha Centauri was the closest to the Earth. Sirius was the brightest. Of course, it wasn’t as bright as Venus but that didn’t matter because Venus was a planet and didn’t really shine.<br />
  5. 5. My universe was stretching quite a bit that night, and my fresh and largely untested mind was struggling to keep up with it. Stars were suns like our own. So why did they only glow at night-time? And what was a planet if it wasn’t a star? I could see Venus, and it looked as much a star as any other dot in the sky.<br />
  6. 6. I can only recite my side of the story. Whatever the impression my wise old brother had tried to make on me that night, he had condensed the nebulous, ignored material of the universe into stars which had names, colour, size, age and distance. It had never occurred to me to ask how high the sky was, but now I could say with authority – because my brother had told me so – that the stars were very, very, very far away, that they were incredibly old and that,… and that quite possibly there were worlds up there with people on them, people who right now were standing in their driveways looking down at us.<br />
  7. 7. We decided to send them a signal using the big red torch we used for camping. The air above our heads was laden with smog and our torch poked a glowing rod through it as electric and scientific as any laser beam I’d seen on TV. I stood for a while waiting for a return signal, but my brother informed me that it might take a while for a response. Perhaps if I went outside the next night, I might see something.<br />
  8. 8. Well, I have looked up at the stars many nights since then, and forty years have transpired. Of the uncountable trillions of photons we released from our torch into the universe that night, a handful may have made it through the atmosphere and out into deep space. In that case they are more than three hundred trillion kilometres from the Earth, more than ten thousand times the diameter of our solar system. They will have fanned out into a cone millions of kilometres wide. Some will have been scattered by interstellar dust into unintended directions. <br />
  9. 9. In the same way, my own energy has been dissipated and scattered and I have little to show for my lack of focus. I still look up at the stars at night. I have this expectation that I know is wrong, this remnant belief from my childhood that if I just stand here and look up at the stars long enough, I will see something happen, something unprecedented and wonderful that will suddenly change the way things are done on Earth, and I will have been amongst the first to see it.<br />
  10. 10. The magic of the stars is not what they do but rather, what their inaction tells us. Characters like Tycho Brahe and Charles Messier catalogued the positions and brightnesses of the stars, four hundred and two hundred years ago respectively, and because of their fastidious obsession we can tell that no star has moved or withered and died in the time since then. More significantly, because we now know how stars work, we can be sure that these same stars have been in our skies, unblemished and unfazed by our progress since at least the time of our earliest hominid ancestors. <br />
  11. 11. Stars are essentially immortal; everyone who has taken the time to look up at the stars has looked up at the same stars that we see today.Aristotle looked these stars. So did Galileo. Columbus and Magellan navigated their ships by them. Copernicus and Kepler deduced the nature of the solar system by looking at them. These are our stars in the sense that they have been with us through every step of our journey, right up to the present day. And yet they are just an infinitesimal sampling of the quadrillions of stars that truly make up our universe. <br />
  12. 12. It was only ninety years ago that a fellow named JacobiusKapteyn looked very carefully at the positions of the stars and determined that they seemed to be arranged in a sort of lens-shape, not about the Earth but about some spot hidden behind a swath of interstellar dust. The thousands of stars that make up the Milky Way, therefore are not the universe but are just the nearest splash of it, about as much of a milk bottle as the bit that dribbles on the table as we lubricate our cornflakes in the morning.<br />
  13. 13. A few years later, a fellow named Edwin Hubble looked at a strange, fuzzy star through his telescope and realised that it wasn’t a star at all but another lens-shaped cluster, as big as our own. This new ‘galaxy’, he determined, lay about eight times as far from us as the farthest edge of our own galaxy, making the universe very much bigger – and emptier – than anyone had ever guessed. What a great time to be an astronomer! Within a single decade, our concept of the universe had expanded in volume a thousand times.<br />
  14. 14. But then comes a fellow by the name of Willem De Sitter, who simply wanted to know if any of these galaxies were moving towards us or away from us and found to his surprise that almost all of them were moving away from us, the furthest of them receding at the greatest speeds. Unintentionally, it was confirmation of a mathematical requirement of Einstein’s theory of relativity, a requirement so ridiculous that Einstein himself had even refused to believe it, which is that the space between the galaxies is swelling up and pushing the galaxies apart from one another.<br />
  15. 15. By my rough reckoning, the universe has swelled by 0.0000002 percent since I first heard about it, thirty years ago. As small an amount as it seems, it means that Andromeda, the galaxy identified by Hubble and the nearest galaxy to our own, is some fifty billion kilometres further away than it was when I was at university. Other galaxies further out have receded even faster.<br />
  16. 16. The stars have always been just a little bit beyond our grasp, but now it is possible to state that fact mathematically: One day, a hundred trillion years from now (give or take) the distance between stars will be so great that the debris from their terminal explosions will no longer be able to coalesce to form new stars. The universe will fade to red and die like a bonfire that’s been torn apart.<br />
  17. 17. A hundred trillion years may seem like a long time, but I would like to put that number up against the (current) size of the universe to give it some context for comparison. If we are ever to venture out into the universe and explore every corner of it before our time runs out, we will have to cover a distance in excess of two billion kilometres a year, every year until the end of time. At that rate of exploration, we would pass Jupiter and Saturn within the first year, Uranus in the next year, and Neptune and Pluto in the third. <br />
  18. 18. This may not sound like too much of an upgrade from what we are doing already with spacecraft like Pioneer and Voyager, but remember that the stars are not all sitting in a straight line and that we will need to expand out into the universe in all directions at once. Double the radius from home and there is suddenly four times as much territory to explore. Increase the radius tenfold and there is a hundred times as much territory to explore. By the time we get to the other end of our own galaxy, the frontier of human exploration will be a sphere with 4,000,000,000,000,000 times the area of the sphere enclosing the planets of our own solar system. <br />
  19. 19. By that stage we would be passing through a region of space as big as our own solar system once every eight nanoseconds.<br />Perhaps this is not the right way to look at things. Stars are not evenly distributed around the sky. The galaxy we live in is more of a disk than a sphere and the gaps between the galaxies probably don’t need to be explored. So let me talk instead in terms of the number of star systems to explore, irrespective of where they happen to be:<br />
  20. 20. There are (astronomers believe) a couple of hundred billion or so stars in our own galaxy. If we explore just one star system every year, starting from today, then we will need a couple of hundred billion years to explore just our own galaxy. During that time all of the stars we see today will have collapsed and exploded and formed themselves into new stars, which means we will have an entirely new galaxy to explore even before we think of travelling any further out into space. And there are perhaps two hundred billion galaxies overhead, each containing about two hundred billion stars.<br />
  21. 21. The point is that no matter how fast we travel out into the universe, we will never get to see it all. I’m a little sad when I contemplate that, in the way that a young man or young woman might feel sad knowing that there are perfect lovers and friends out there in the world today that they will never meet because the distances are too great and time is too short. If civilisations such as ours can develop in the universe beyond our own peculiar world, then there will be many that we will never meet. <br />
  22. 22. Their stories, their wisdom, their view of the way things work, even their dirty stories and silly jokes; we will never know of these things simply because we will not have chance to meet them. Inverting that same line of reasoning, it could happen that the accumulated wisdom of our own species – our struggles and our aspirations, our funny stories and our insights – will never be shared with more than a handful of our neighbours in space.<br />
  23. 23. Last night I invited my wife to come out into the driveway and look up at the stars with me. She shared my enthusiasm for a period of time we both judged to be polite, then told me it was cold and went back inside. I stood outside a little longer, drew a deep breath and turned up my collar to the cold night air. I’m still looking up at those stars after all these years but I’m no longer sure what I’m looking for. I know the stars won’t move and I know they won’t change. Why am I out here?<br />
  24. 24. My son calls me back inside and it’s to see pictures attached to an email from one of our relatives in Singapore. I marvel at how my brother-in-law can be digitised and teleported, Captain Kirk style, up to a satellite in space and then down again to our living room, to appear on the screen of my laptop.<br />
  25. 25. I marvel, too, at how quickly the internet was set up so that people at opposite ends of our social universe can meet and exchange details of their lives. We are social creatures, we humans. Our strength has always been our ability to spontaneously organise ourselves into teams and apply ourselves to some greater, collective cause. The railways of the world were built by teams of largely unremembered and probably quite unremarkable men and women. So were the telephone networks, not to mention radio and television. <br />
  26. 26. Ideas come from individuals, but implementing and disseminating those good ideas has always been the work of teams who may or may not know in their own time the true historic value of what they are doing.<br />
  27. 27. Think of Facebook and the other social networks that some say are a blight on the cyber landscape. No spy agency could ever have hoped to compile detailed information about every human being alive in the world today. Yet the creators of Facebook are well on their way to achieving just that, and all they are doing is standing back while the biggest team in human history i.e., over a billion people jump aboard and add their own little bit. It’s only taken a few years.<br />
  28. 28. This frivolous flurry of social networking that we are living through today is just the first clumsy step towards exchanging knowledge on a global scale, global in the sense that it includes every living individual who chooses to participate. Perhaps ninety-nine percent of what they will write online is worthless to ninety-nine percent of those who will read it, but the remaining one percent of it – and which one percent? – will mean something to somebody.<br />
  29. 29. It occurs to me suddenly that on all those occasions I have stood outside at night looking up at the stars, I have not really been looking up but looking in. My knowledge of those stars – their names, their colours, their size and age and so on – came not from the stars themselves but from books about stars and listening to people talk about stars. It was the social universe that enabled me to understand the physical universe, and so it will continue to be as we eventually progress out there in the years ahead.<br />
  30. 30. There are over six billion people in the world today, and about two hundred billion star systems in our galaxy. That’s thirty-three star systems each. Who knows how many of us may exist when that first task of exploration is complete and we raise our heads to consider the other galaxies? We may or may not ever have the time and energy to explore the universe, but as long as we continue to chat with one another we will certainly have the numbers.<br />