The Expanding Universe and Dark Energy.

The Expanding Universe

As we know galaxies are moving away from each other, not moving through but with space, space itself is expanding. We can take it's idea by looking at the example of  loaf of a raisin bread. As the dough rises, the raisins (representing bodies in space, such as galaxies) move away from each other and so does the dough they rest in. The phenomenon of The Expanding Universe is a property of the Universe as a whole and not just of galaxies.

Edwin Hubble (an American astronomer) was the first who discovered that the Universe is expanding in year 1929. With Hubble's findings, astronomers found that Universe is not only expanding but accelerating as well. Many astronomers believe that the acceleration in expanding rate of universe is due to because of Dark Energy, a type of antigravity force from deep space.

The Dark Energy, about which we don't know very much, probably determine the fate of the Universe depending on it's stability. If the dark energy is stable, the Universe might continue to expand and accelerate forever. On the other hand, If it is unstable, the Universe might eventually be pulled apart which is termed as "big rip". Also, if the dark energy has the capacity to change, it could eventually retard and might become an attractive force that contracts the Universe which is termed as "big crunch".

Dark Energy

The scientists have given the name "Dark Energy" to the force responsible for The Expanding of Universe. Dark Energy is the opposite of gravity: it pushes things away rather than pulling them together. It is unknown to us whether the laws of physics can be applied for dark energy or not. In year 1998, astronomers studying supernovae found them dimmer than expected which clearly meant that the Universe was expanding at much faster rate than expected.