Throughout your experience here at the Cosmic Wonders Corporation, you will or may have already seen great wonders of space. Now many of these wonders are just stages in stars’ lives. Think of them as multiple generations of stars. In this article, we will more closely detail the life cycle of stars and how it pertains to the wonders you will see.
  By no means do stars just ‘appear’. Stars are formed by interstellar gases and dusts, heated to 8.5 million degrees Kelvin. These gases and dusts slowly begin to collapse in on themselves due to the immense gravitational situation in the dust cloud. As the core begins to form, temperatures rise and plasma begins to form. Eventually, the pressures and the heats cause nuclear fusion, setting up a stable source of energy and outward force to counterbalance the great force of gravity acting on the newly-born star. Stars come in a variety of sizes and temperatures, but the size and temperature of the star is always related the same way. Flame is hottest when blue, and so are stars. Stars that are blue tend to be on the order of 20-30 times the size of our sun, a yellow star. So as is obvious, the amount of mass available in the gas and dust cloud has to do directly with the size and temperature of the new star.
  Stars spend their lives in galaxies, your first stop on the CWC galactic tour. The life of a star is hard menial work, consisting of fusion and then some more fusion. For more information about galaxies, just board your personal spacecraft and get started! 
  Stars do die, as all things must. Like most of us, most stars pass quietly without much of a report, while others choose to let all know of their timely demise with viciousness and savagery.  Stars close to the size of the sun tend to go quietly. First, when most of the hydrogen in the star is burned, the star begins to collapse in on itself, generating a great amount of heat, temporarily offsetting the gravitational effects of the dying star. The result is a red giant. When our sun becomes a red giant, the earth with be torched by the outer layer of the sun. Then global warming will really start to kick in. Soon, the heat fades, and the outer layers of the star are shed (perhaps forming a planetary nebula, which you will learn about later), leaving the newly formed carbon core to cool for a long time to come as a white dwarf. 
  Now the violent ending is much more fun! Stars of a larger variety begin the process of death much the same way as the smaller ones. The core begins to collapse and the outer layers expand because of heat. Because these stars are so massive, the cores produce neutrons, which shoot into the outer layers of the star causing what is known as a supernova. After this huge release of energy, the star collapses again to form a neutron star, or pulsar. If massive enough (and lucky too), the collapsed star can wreak havoc for eons to come by collapsing completely and becoming a black hole. But most importantly, the remnants of a supernova or their shockwaves can form nebulae, the birthing grounds of stars. You may visit supernovae, black holes, nebulae, pulsars, and quasars on your tour to learn more.
  So as you can see, stars are born and stars die, triggering new starbirth: it truly is a cycle. Your journey through the CWC tour will take you through many generations of star-life. Thank you for joining us on this basic training tour of the Life Cycle of Stars.
 

  In this section of the Basic Training, one will learn the basics of Special relativity, which is crucial to understanding some of the spatial concepts put forth in the vast expanse of space we have put together for you, the touring citizen. 
 Special relativity has to do with frames of reference.  This term can best be explained by example.  Imagine yourself on a platform which is moving.  Imagine then that you are moving along the platform.  In your reference frame, or the platform frame, you are moving at the velocity of your walking speed, no more.  Now imagine a man standing outside the platform watching you walk.  This man recognizes that you are moving with a velocity V+V1, or your walking velocity plus the velocity of the platform moving under your feet.  So as you can see, the rate at which things are perceived to be moving is different in the different reference frames.  For this example, both reference frames were what is called "inertial" reference frames.  What is meant by that is both of the frames have a constant velocity and are not be acted on by any unbalanced outside force.  This example given above is an example of the Galilean transformation.  The Galilean transformation fits into Newton’s laws set forth so many years ago, something physicists like.  So it seems that classical mechanics holds well for the Galilean transformation of frames. 
  Unfortunately, there is a minor problem with the Galilean transformation.  Let us look at the example again.  Perhaps the man on the platform is holding a flashlight which is shining in the direction in which he is moving.  This seems reasonable.  The man moving along the platform measures light to move at velocity c, normal.  The man at the end of the platform, not moving with relationship to the platform, has the light shined in his face.  For him, would he measure light at c+V1, or the speed of light plus the velocity of the platform?!  Light is supposed to be a constant speed, is it not?
  Contrary to what was said earlier, this is actually a major problem.  The problem was perceived to be a problem of measurement in relativity.  In other terms, what is light measured relative to?  In the late 1800’s a man named Maxwell could not imagine how light could broadcast through no medium.  Sound waves traveled through water and air; what did light travel trough?  A concept called the ‘Ether’ was developed that seemed to solve the problem with the measurement of the speed of light in the Galilean frames and the problem with the medium.  The ether was at rest with relation to the stars.  Newton’s laws seemed not to hold for the electromagnetic phenomenon. 
  The ether was a hot topic and many scientists  sought to prove it.  A duo named Michelson and Morely came up with an idea to test the ether hypothesis.  To make a long story short, they were looking for interference patterns on the instrument they invented, the interferometer.  The expected change in the interference patterns did not take place.  This was a shock, as most scientists of the time believed in the ether hypothesis.  This experiment was reproduced many times by many people all with the same nil results.  Slowly, the ether hypothesis died.  Apparently the Galilean transformations and Newtonian mechanics are not good enough for all situations: Einstein’s special relativity must come in to roll with the punches. 
  Without the in-depth calculus, let us just say that a new frame transformation method comes into play called the Lorentz transformation.  This transformation makes the speed of light independent of the motion of the source or receiver.  So the two basic postulates of Special Relativity are that the laws of physics are the same in all inertial reference frames and that the speed of light is constant. 
  Perhaps the biggest and most talked about effect of special relativity is Time Dilation.  Imagine the example given at the beginning of this article.  Imagine then that there is a mirror stationed above the man moving along the platform.  The mirror is moving with velocity V1 with relationship to the ground, that is, it is moving with the platform.  Now the man on the platform shines his light at the mirror, it reflects and a time measurement is taken to see how long the trip took.  At the same time, the man on the ground watches and times the trip as well.  Let us look at the following diagram:

  The man looking on sees the light travel a greater distance than the man on the platform because the platform is moving giving the motion the triangular appearance.  Because light always moves with velocity c, as stated by Einstein, the man on the ground sees more time elapse than the man on the platform.  It is observed that the man on the platform’s clock is running slow.  This is time dilation, a fascinating effect of special relativity.  So it seems that the faster one moves, the greater distance light travels in the observed inertial reference frame, and therefore the slower time seems to move for the object moving at faster speeds. 
  The second and last effect of special relativity we will discuss here is length contraction which works very closely with time dilation.  Imagine this example.  Using similar circumstances from the previous example, the men in the example want to measure a big hoagie they got at a restaurant.  The man in the ground frame measures the sandwich properly, giving the proper length.  As the man on the platform moves through the room, the man on the ground measures the time taken by the man on the platform improperly.  The man on the platform does the opposite.  He has the correct time taken on his journey through the room, but the measurement of the hoagie is improper.  This is the close relationship between time dilation and length contraction.  So for the compensation of time dilation comes length contraction.  As time seems to slow down in relation to zero velocity when traveling at near light speed, lengths expand or as objects move by an object at rest at high velocities approaching c, time seems to dilate and lengths contract.  These two phenomenon are interrelated in the theory of Special Relativity.
  To recap, the postulates of Special Relativity are that physical laws are the same in all inertial reference frames, and that the speed of light is a uniform speed, the same in all inertial reference frames. 
  Without much more detail, this is Special Relativity in a Box for your better understanding of the world and the heavens as we take you into the wonders of space.
 

Relating to special relativity is Space-Time. Space and time can be thought of as non-absolute, one depending on the other. Think about the connotations of the relativity basic training article. Space and time are not absolute, as one approaches c, light speed, time slows and lengths expand. Approaching c, an object's mass approaches the infinite.  But we digress. As you can see, Einstien theorized that space and time are interrelated, and that the space-time continuum, as it is called, can be warped. To imagine this, picture a rubber sheet. Time and space flow smoothly along the surface of the undisturbed sheet. Now imagine an object of a large mass placed on the sheet. The sheet begins to bend downward, the curvature of space-time is evident. This is how our universe is: space-time curves in the region of any mass.

  Now imagine a singular object of enourmous density and mass placed on the sheet. The sheet bends dramatically. This is a sigularity, an immense disturbance in space time. Once inside the event horizon projected by the singularity (you will learn about these later, in black holes) nothing can escape into the 'real' universe, because it is trapped in the curvature of the massive space-time rift.

  Space-time curvature can also be used to explain the effects of special relativity. As was said earlier, as an object moves toward velocity c, it assumes a greater and greater mass, thereby causing a greater fluctuation in space-time which can explain the time dilation and the expanded lengths.