Our Universe
Our universe is
everything that we can touch, sense, feel, observe, measure and detect. it
includes all of us, living things, stars, planets, galaxies, dust clouds, light
and even time. before the birth of our universe space, time, matter, nothing
exist.
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| our universe |
Our universe
containing billions of galaxies, each of galaxies contains millions or billions
of stars. but the spaces between these stars and galaxies are largely empty. however
this spaces are not fully empty they contains scattered particles, dust or few
hydrogen atom per cubic meter. Space is also contains radiation, magnetic
fields and high energy particles(eg. light, heat, cosmic rays).
The size of
universe is incredibly huge. If we want to go to our nearest star then it take
more than millions of year from our fighter jet. To cross our milky way it
would take 100,000 years at travelling with the speed of 3oo,ooo km per second.
Our visible
universe is more than 93 billion light years in size. Where, one light year is
the distance that light travels in one year and it’s nearly about 9 trillion
km. we can’t no the exact size of our universe because no one se the edge of
universe if they exist.
The size of our
universe has not always been same .our universe is began with big bang before
14 billion years ago. Since then, at very high speed our universe has been
expanding in outward direction. So the
area of space is expanding billions of time grater than it was when our
universe was young. Galaxies and stars are moving apart and so the space
between them has expands.
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| shape of universe |
Our universe is made from
spacetime fabric. Shape of space and time is define by general relativity. it
says how spacetime curved and it’s bent by mass and energy. because of space
time is curved we can’t see the whole universe. The section of universe which
is observable is backward light cone. They delimits on cosmological horizon. Horizon
represents the boundary between the observable and non observable universe.
Astronomers calculate the
age of universe by lambda-CDM model. Assuming that it accurately describe the
evolution of universe from hot, dense primordial state to present state. Measurements
of parameter by variety of techniques and numerous experiments we find the best
age of the universe which is about 13.799 billion year raging from 0.021
billion year more or less.
