Our big big Universe  The Universe is big, everybody says that, after all it is the biggest thing we can think about. Maybe it's also unlimited, here we will only see how big is the "seen" universe, how distant our telescopes (or better, radio telescopes) have gone. The numbers you will read here are quite approximate and maybe not that updated but they can give us an idea. The language can be irritating for who knows something about astronomy, anyway it is intended to be as clearer and easier as possible. Let's start from our lovely Earth. It seems so big, you realize it when you travel to your favorite holiday place. In fact its diameter is about 12.750 Kilometers. Not bad indeed. The diameter of the Sun is 109 times the Earth's one and the average distance between them is about 150.000.000 Km. Pluto, the farthest planet of our solar system is about 40 times farther than the Earth (average distance). The light is the fastest thing we can consider, even fastest than your new car, it makes 300.000 Km in a second. The mathematical minded among you have already calculated that the light travels the Earth-Sun distance in about 8,3 minutes, the diameter of the Earth is crossed in 0,04 seconds and Pluto has to wait 5,5 hours to see a ray of light from the Sun. If we consider the Earth like a 1 centimeter wide sphere, the sun is a 1 meter sphere distant 125 metres and Pluto is a lame 0.2 cm ball distant 5 Km. Quite impressive eh? That's nothing. The nearer solar system is the Alpha Centauri one. This one is quite far from us: 2 (or 4? don't remember...) light years, in the example considered before is something distant 15.000 Km! That's the nearest star excluded the Sun of course. All the stars we see in the sky belong to our galaxy also called Milky way. Our galaxy is a spiral with the diameter of about 120.000 light years. Compare this distance with the others written before and try to make yourself an idea. The nearest other galaxy, if we don't consider the little and "satellites" Magellan clouds, is Andromeda. Andromeda is quite similar in dimension and shape to our Milky way. It is 2.000.000 light years distant. If we are lucky enough we can also see it in the sky with our eyes. The farthest "things" seen by our telescopes are the quasars. They are really far: up to 15.000.000.000 light years (this value is very approximate, new "distance records" are normal). The quasars can be galaxies at their birth, they are not only far in space, they are also far in time, we "see" them as they were milliards of years ago (the time the light has taken to come until us). So the known universe is "long" something of the order of 10-20.000.000.000 light years. Before going on think again about the Sun, Pluto, Alpha Centauri and their dimensions. Ok, so we live in a fucking big universe, I hope you have realized that. Sure? Well, just to confuse a little your ideas here is a little game. Let's take a normal sheet of paper (0,1 mm thick), let's fold it at its half. We obtain a paper with double thickness and half dimensions. Let's fold it again, we have a paper with four times the starting thickness and a quarter of the starting dimensions. Let's imagine to make this operation 100 times (of course is impossible but we consider it possible). How long is the final thickness? Well, do you remember our big universe and how long is it? Believe it or not (just a matter of some not difficult mathematical operations) our 100 folded piece of paper stays hardly in the whole known universe. It has the same length!  Macno/GRACE