INTERESTING Q AND A

Here are some of the amazing facts and figures related to the UNIVERSE. 

Is Speed Of Light Fixed?

The fact that light travels at a finite, but very high, speed was first discovered in 1676 by the Danish astronomer Ole Christensen Roemer. 

Maxwell's theory predicted that radio or light waves should travel at a certain fixed speed. But Newton's theory had got rid of the idea of absolute rest, so if flight was supposed to travel at a fixed speed one would have to say what that fixed speed was to be measured relative to.

The best-known equation showing equivalence of mass and energy, was summed up as Einstein's famous equation E= mc^2, states that nothing can travel faster than speed of light. Because of the equivalance of energy and mass, the energy which an object has due to its motion will add to its mass. In other words, it will make it harder to increase its speed. As an object approaches the speed of light, its mass rises ever more quickly, so it takes more and more energy to speed it up further. It can infact never reach the speed of light, because by then its mass would have become infinite, and by the equivalence of mass and energy it would have taken infinite amount of energy to get it there.

For this reason, any normal object is forever confined by relativity to move at speeds slower than the speed of light. Only light, or other waves that have no intrinsic mass, can move at a speed of light.

What Would Happen If Sun Disappears Suddenly?

Newton thought that gravity was a force that acts instantaneously across any distance and so we will immediately feel the effect of Sun's Destruction and Planets will immediately fly-off tangentially to their orbit. 

Einstein saw a big problem with Newton theory. A problem that arose from his work with light. Light from sun doesn't reach the earth instantaneously. In fact, it takes about 8 minutes for the Sun's rays to reach 149.6 million km (93 million miles) to the Earth. And since he had shown that nothing can travel faster than light. NOT EVEN GRAVITY!! So, how could the Earth be released from its orbit before the darkness resulting from Sun's disappearance reached our eyes. According to his theory- " If Sun disappears suddenly, the resulting gravitational disturbance form a wave that travel across the spacial fabric in much the same way the pebble dropped into pond makes ripples that travel across the surface of the water. So, we would not feel the change in our orbit around Sun until this wave reached the Earth." 

How Do Astronaumers Use Maths in Their Job?

Astronomer use maths all the time. One way it is used is when we look at objects in the sky with a telescope. The camera that is attached to the telescope basically records a series of numbers – those numbers might correspond to how much light different objects in the sky are emmiting, what type of light, etc. In order to able to understand the information that these numbers contain, we need to use  maths and statistics to interpret them. 

Another way that astronomers use maths is when they are forming and testing theories for the physical laws that govern and objects in the sky. Theories of cyst of formulas that relate quantities to each other (a very simple example is Newton's law, force = mass times acceleration). In order to be able to test these theories and use them to make predictions about what we will observe in the sky, astronomers need to use maths to manipulate the equations.

Why Pluto Is Not A Planet?

In early times Pluto was considered as the nineth Planet of our Solar System. But in the 26th General Assembly of International Astronaumical Union (IAU) in 2006 Pluto was declared as a Dwarf Planet. 

On 18 February 1930, American Astronomer Clyde Tombaugh discovered the nineth planet Pluto. While all the Planets orbit Sun in almost a round shape, Pluto's orbit was extremely elliptical and it takes 248 Earth years to complete its one revolution. At first it was believed that Pluto's mass was approximately equal to that of Earth's but later when its moon Charon was discovered then we came to know that Pluto is very smaller than Earth and has only 0.02% of Earth's mass.

But Discovery of one more Dwarf Planet Eris forces the IAU to change the definitions of a Planet. An object is considered as a Planet if it fulfills the three following check boxes.

1. The object must be orbiting the Sun.

2. It should have sufficient mass to assume Hydrostatic Equilibrium (a round shape).

3. It should "clear the neighborhood" around its orbit meaning that all the Asteroids around it should orbit it or collide into it.

This third criteria was new in the definition and this was the only one criteria which is not followed by Pluto. This is the main reason why Pluto is not considered as a Planet.