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Understanding Space and Universe.

posted Jun 6, 2019, 11:33 PM by Upali Salpadoru   [ updated Jun 24, 2019, 12:11 AM ]



Courtsey: National Geographic.

A dictionary defines space as “a continuous area or expanse which is free\

, available, or unoccupied. ” Where do you get any space which does not

contain anything?”. The atmosphere is filled with air. What we normally called space

is the solar system that holds the planets, meteors etc,  One may say there is empty

space in between the planets. Up to the19th Century scientists thought of an imaginary

substance called ‘ether’ to be occupying this expanse. This was a matrix (medium)  introduced

to explain the wave theory of light..When Albert Einstein, based on the discoveries of Lennard

and Plank, explained the ‘photo electric effect’ considering light can also behave as  packets

or quanta which he named as photons  ether theory was abandoned.

  In 1940 Russian astronomer George Gamow predicted that the Electro magnetic radiation produced

at the creation of the universe must still be present in space as a cosmic background radiation..

He also affirmed that we should be receiving them mainly in the microwave region. In 1964

while a  Princeton team, led by Robert H Dicke, was looking for them a few km away Arno Penzias

and Robert Wilson accidentally discovered the faint cosmic microwave back ground (CMB)radiation.

They received the Nobel Prize in 1978."When we first heard that inexplicable 'hum,' we

didn’t understand its significance, and we never dreamed it would be connected to the origins of the universe," Penzias said. You also can get this as the snow screen on your TV.

   Detecting of the CMB gave a good boost to the Inflation Theory of the universe. In 1927 Georges Lemaitre based on the known facts at the time. proposed that the universe is expanding.

  Edwin Hubble  studied the red shifts of 46 galaxies and showed that the velocity of receding galaxies is proportional to the distance. This came to be known as the Hubble’s law.  v = H0 D,  ( v = velocity. D = distance and H0   Is a constant. )

    Although there is some confusion regarding the value of  H0  it is a simple task for the mathematicians to calculate the  birth of the Universe using the Hubble’s law. The scientist now agree that the universe started from a fine speck bursting at a terrific speed covering billions of kilometers in a fraction of a second. This speck has been named a singularity. At present the age of the universe is taken as 13.77 billion years a few 100 million plus or minus.

 It is a universal law that nothing comes from nothing.  (Latin: ex nihilo nihil fit) As Antoine Lavoisier stated it Matter can neither be created nor destroyed”  

Sir Fred Hoyle a renowned British astronomer rejecting it over a lecture on BBC  calling it a Big Bang Theory. The name has got stuck since. He supported the Steady state Theory, according to which  the universe had no beginning and there will be no  end.

   Now it has been discovered that the galaxies are actually accelerating. There cannot be an acceleration without a force. What is this unknown force? The force we know is the gravitational force. This is an attraction which should actually slow down the receding galaxies. Scientists have a theory of dark energy in an attempt to answer this. They also have imagined a strange kind of matter called dark matter to be filling the entire space.