A Little about the Universe

Today, we know that the universe is expanding, how do we know this.  First, you will need to know how the universe was found to be expanding and also to understand why it is expanding.

The Big Bang

About 15 billion years ago, the universe was void and without form, all the matter in the universe that we see today was at one time compressed at a point that was smaller than a atom.  One day this point of matter exploded into matter and energy expanding throughout the vacuum of the nothingness that was the universe.  Expanding at a rate close to the speed of light, the universe cooled.  This is what the Big Bang theory states.  It is the most accurate model we have to describe the origins of the universe.  From that one point, all matter and the universe was formed, all energy was released.    It took billions of years for the matter to cool down, we call this cooling background radiation, it shows the universe's cooling effect. 

Doppler Effect

Light is constantly moving, wither towards us or away, the reason for this is because light is made of subatomic particles called photons.  Photons have mass, but is so small it is nearly immeasurable.  Light, while having mass and particles also move through space in waves, such as a sine wave.  This gives light the appearance of shortening and lengthening depending on where you are positioned from the light.  This shortening and lengthening is called a doppler effect.  We encounter this effect everyday, say for instance a car is blowing its horn as it drives by, you hear the horn rise and fall in pitch as the car comes toward you and then moves away.  Light is the same way, but instead of raising higher or lower in pitch, it raises higher and lower in color.  Light is blue when it comes toward you and shifts red as it moves away, this is the doppler shift and it helped Edwin Hubble to conclude that the universe is indeed expanding.  Hubble did this by attaching prisms to his telescope, the prisms are called spectrometers and braek up white light into many different colors, just like a prism we have all played with as children. 

  NASA has found a Way to Make the Blind See

Nasa is working on making replacement eyes for   those who are suffering from one form of bllindness.  These eyes are made from silicon wafers that act as cones and rods