Every civilization that has had an unobstructed view of the night sky has always looked up, and seen themselves represented in the stars. Our biggest questions come when we are looking up: where do we fit in among these millions and millions of tiny jewels? They must govern our attributes as people, or our gods must watch over us from them, or we must be immortalized up there after we die! For ages all we could do was wonder, and wonder we did. It was this everlasting wonder that drew us to explore the cosmos and our place in it, and, through science, we were able to discover that our ancestors were not far from the truth when they made those bold claims about the twinkling lights in the sky.

Though the heavens and its inhabitants are beyond comprehension, we have discovered much about them through scientific exploration. The size of the universe around us and the time that it has inhabited are mind numbing, but its contents are not. Those twinkling lights? Any child in elementary school will tell you that they are stars; their characteristics no different than those of our own sun. What they wont tell you, though, is that they are the true creators of man and Earth. If it was not for their energetic lives and extremely turbulent deaths, life on Earth, and also the Earth itself, would not exist. They are our inspiration, our nurturers, and our ancestors; their lives are our lives and this is the tale of how we, and almost all other types of matter, were sown by seeds of stars.

In the beginning there was neither light, nor energy, nor space, nor time. Then, in a split second, 13.8 billion years ago, they universe was created from seemingly nothing, and all of these things expanded into existence. Though this event was the creation of everything that is and that ever will be in the universe (since matter and energy can neither be created or destroyed) it did not create a great variety of things. The most notable things that were created during this “Big Bang” were: the four Forces (gravity, electromagnetism, weak, and strong), the three lightest elements (Hydrogen, Helium, and a smidge of Lithium), light, energy, and, of course, time and space. There are also a few very, very, lucky (or fate-y) coincidences that took place at this time, and allowed our Universe to exist. The first being: that matter and energy were unevenly distributed, ever so slightly.

Had all matter and energy been uniformly distributed, gravity would not have been strong enough to over come the space between particles and the universe would forever be an extremely light dusting of atoms. The second miracle was that slightly more, try 1/billion more, matter existed than anti-matter. Since antimatter and matter incinerate into pure energy upon contact, this slight offset allowed the entire universe to exist. Think about that for a second, every man and woman, every plant and animal, every star and galaxy; is one billionth of all the matter that was originally created in the Big Bang. It is these two miracles of disequilibrium that allowed the universe to expand and grow.

Whether you call it chance or divine intervention, it does not matter; us humans will probably never truly know why our universe was lucky enough to exist. What we do know is that no humans were created in the Big Bang. You did not see any stars or planets explode out with space and time; only the three elements: Hydrogen, Helium, and Lithium. But what about the 115 other elements on our Periodic table, that we know as the building blocks of all matter? They were all created later, in the Universe’s own furnaces of creation. You guessed it: stars.

Hydrogen is the the lightest, most abundant element in the Universe. The uneven distribution of Hydrogen after the Big Bang created some areas were Hydrogen was densely packed enough for the force of gravity to cause them to attract. As the clusters of Hydrogen got larger gravity pulled more and more of the gas together, and the clumps of lightest gas began to get very dense. Density builds pressure, pressure builds heat, heat means the once seemingly static Hydrogen atoms are beginning to wiz around the growing blob of Hydrogen; colliding into each other more and more force. Eventually, as the cluster of Hydrogen gets phenomenally hot, the collisions grow so intense that when the Hydrogen atoms collide they no longer ricochet off one another. Instead they fuse into a new element, creating such a colossal amount of energy that a star is born.

When two Hydrogen atoms fuse, their nucleuses combine and a Helium atom is made. This process releases so much energy that it is able to create, and fuel, a star. (Us humans use this same process to construct our most destructive weapons: Hydrogen Bombs). Our sun is constantly undergoing this matter transformation, fusing lighter elements (like Hydrogen) into heavier ones (like Helium). The light and energy it produces powerful enough to sustain all life on Earth.

Even after a star runs out of its Hydrogen fuel, it will continue the fusion chain reaction, fusing Hydrogen atoms together to create Helium (the second lightest element), then fusing Helium atoms to create Lithium (the third lightest element) and on and on. The larger a star is the more elements it can forge during its life, because heavier elements require more heat, and thus, bigger stars to create fusion. Eventually all stars will burn out as they create elements that are to heavy to fuse any further. The largest stars can create elements as heavy as Iron, the 26^th element on the Periodic table (therefore the 26^th lightest element), before they can no longer continue fusion. The average sized stars (around the size of our sun) can generally fuse Carbon or Oxygen (six and seven, respectively, on the periodic table) before running out of fuel and collapsing in on themselves, releasing all but their heaviest elements to travel forming dust clouds that may later become new stars or planets. The heaviest stars, the ones that can fuse elements all the way up to Iron, do something a little different. They do not just collapse in on themselves…

THEY EXPLODE

By the time that the largest stars get big enough to fuse Iron, the force caused when it exhausts its fuel and collapses causes on of the most awesome events in the Universe, the Supernova. A Supernova caused by the collapsing of a giant star is an explosion so powerful that an average supernova becomes more luminous then of all the stars in its home galaxy combined. The force of a supernova is so tremendous that it is only way that the remaining 92 elements, the ones heavier than Iron on the periodic table, can be fused into existence. They are then flung out into the cosmos, every element that can possibly be created, the elements needed to construct everything from comets, to planets, to people, to the silicon in your computer. It is out of the ashes of these dying stars that the universe is fertilized, and we are able to exist.

Take a second to think about that, everything, literally everything you see right now was forged in the furnace of a star. Stars were able to create the building blocks of Earth and the Universe out of the three original elements and gravity. Your computer was made inside of a star. Your dog, made from matter created and flung into the galaxy by a star. Your right hand, made in the belly of a star. Your left hand, made inside the belly of a potentially different star.

This is the first time in history that we don’t have to wonder where we fit in among all those twinkling lights in the sky. Because we are those twinkling lights in the sky. You, me, and everyone you know is, literally, star stuff. We are the Universe experiencing itself and every time we discover more about the Universe, we discover a little bit more about ourselves. Take this into account the next time you look up at night and realize: The Universe is not this Heavenly force as far away as those twinkling lights. The Universe is all around us, we are the Universe, we are the manifestation of billions and billions of years of destruction and creation, and we are not only exploring our home but also ourselves.

http://press.web.cern.ch/backgrounders/matterantim...