Why the Earth revolving around the Sun? And Why the earth also spinning around it's own axis?

Hey friends,
Today we learn about another interesting topic about revolving of the earth around sun and spinning around it's own axis. From primary class to higher class we learn that earth revolving around the sun. And spinning around own axis which cause to happening day and night. But you ever thinking why its happen?
   In this article we trying to find out the answer of following questions.

1. Why the Earth (or planets) moves around the sun?
2. Is the sun really positioned in the center of solar system?
3. Why the Earth spinning around own axis?
4. When till the Earth spinning?

Why the Earth (or planets) moves around the sun?

   Every object in the space is moving continuously with relative to its nearest heavier mass object. Earth is also moves around the sun. There are two famous theories behind this.

rotation of earth around the sun

*  First according to Isaac Newton the Earth moves around the sun because the higher gravitational force act on it. The sun is a heaviest object in the solar system ( you can imagine its heaviness by that the sun is 1000 times heavier then biggest planet of solar system Jupiter and its 3333000 times heavier then Earth . The mass of sun is 99% of entire solar system.). According to the definition of gravity the heavier mass produce higher gravitational pulls then light ones.

comparison in size of planets

   There are two main force act on any planet (like Earth) while its moves around any object (like sun) - 

• The gravitational force which act as centripetal force directed towards the center of orbit. This gravitational force is due to the mass of objects.
• The sideway force that directed tangential at that point of orbit. 

There are an other force which act on planet is centrifugal force which acts as reaction of gravitational force (centripetal force). This force really doesn't exist, its a pseudo force which balanced the planet in its orbit. You can understand above concept with ball-string example.

centripital force

*  Second, this is modern theory predict by Einstein. According this ' Gravity is nothing but the curvature in Space-Time fabric '. That means gravity doesn't exist in the real word its a pseudo force. Thus planets moves in orbits on the curvature of heavier mass object. Its move with high rate near the object while slower far from object.

curve in space time fabric

Is the Sun pointed on the center of solar system?

   There is a miss concept we learned from school that the sun is center of solar system. Which is technically wrong. Actually Earth doesn't orbiting the sun they both are orbiting a central point called 'Barycenter'. Barycenter is center of mass of two or more object in the space, around which all object are orbiting. This is a useful concept in astronomy.

barycenter

The barycenter for Earth and Sun is near the center of sun, but it is significant for Jupiter and Sun and lie on the outer surface of sun and the sun also orbiting this point.
   Actually there are also a barycenter for whole solar system which lie around the outer surface of sun. There are no fixed position of barycenter of solar system. Its depend upon the position of planets in their orbits at that time. The barycenter point change continuously as follow.

change in barycenter in defferent years

Why Earth spinning?

   Do you know why Day and Night happen? Earth's spinning is reason behind day and night happening. But why Earth spin continuously?
   Earth spin from west to east with the rate 1670 km/H. The time takes in one rotation is nearly 24 hours ( 23 hours 56 minutes and 4 second ).

spin of earth

Every planets in the solar system has their unique rotation time. Closest Mercury takes 59 day of earth while the second closet Venus takes 243 days.
   Earth is spinning even then every planets or objects are spinning in the space. Conservation of angular momentum is the reason behinds the spinning of planets. When the universe born from the Big-Bang explosion then the gases and the dust particles moving with high rate. Solar system formed only just before 5 Billion years ago from the vast clouds of Hydrogen and Helium and other many dust particles. The sun formed on the center of cloud and remaining clouds are continuously moving. These clouds are colliding or sticking in each other and now thus formed planets and their moons, which are continuously spinning in same direction to balancing there angular momentum conserved.

When till the earth spinning ? 

   Now the question rise from here is when will Earth stop spinning?

why earth spining

The answer is never, yes will never stop spinning. Because its followed the law of Inertia, which says that 'object resist the change in their initial States'. If its moving so, its continuously moving while the some external force work on it. There not present such external force (like frictional force) in the space which resist the motion of planets. Therefore the Earth (planets) are spinning continuously.

Thanks to reading this topic, please share your thoughts and experiences in comment.