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Showing posts from June, 2020

Gravity - Force or Distortion?

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    In 1687, Sir Isaac Newton publishes his theory on Gravity. It says that it a force that attracts any two objects having mass and some distance between them. This explained why everything falls on the ground, why the earth orbits the sun, why the moon orbits the earth. Gravity as a force was accepted generally for some centuries as this theory can be applied to all objects. Indeed it was Sir Isaac Newton who described the effects of gravity, but Albert Einstein was the one to explain how it truly works. Sun and Earth Distorting Space-Time     Albert Einstein predicted through his general theory of relativity that gravity is distortion in the fabric of space-time rather than being a force. Space-time is a concept where the 3-dimensions of space is combined with an additional dimension of time making it 4-dimensional. It explains that the heavier is an object the more it distorts the space-time similarly to an object placed on a stretched out fabric. If any other ob...

Star

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False Image of The Sun[Image Credit NASA]      A Star is a ball of plasma and is a very dense region in space. In the night sky, you can see an uncountable number of stars and even though they look so little, most of them are several times larger than our parent star, The Sun, which is only an average-sized star. A star is capable of helping sustain life on a planet if it is placed at the right distance from its parent star.     One might ask, how does a star shine or how does it generate heat. The answer is Nuclear fusion. Abundant quantities of hydrogen are present in any star. Due to high densities, the hydrogen atoms undergo fusion producing helium and in the process liberate very high amounts of heat and also photons(i.e, light). Every second, around 600 million tons of hydrogen are converted into 596 million tons of helium and the remaining 4 million tons are converted into energy. Carina Nebula[Image Credit: NASA, ESA, Hubble Space Telescope]   ...

The Big Bang

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Timeline of Universe     The Big Bang, according to this theory, this is where it all started. Every star you see including ours, The Sun, our moon, other planets, and many more things originated from this phenomenon. Putting in simple terms, in the beginning, there was this singularity that had a very high temperature and very high density, exploded into the cosmos we know today. In 1927, Georges Lema ître identified that if the time was reversed, the nearby galaxies will converge into a single point. Later it was confirmed by Edwin Hubble and the event was named The Big Bang Theory.      It is rather unclear that time existed before the big bang so it is convenient for us that the time originated from the moment of the big bang. The timelines can be divided into: Singularity: Hubble's law tells us that galaxies move farther from the earth at a speed proportional to its distance to earth. Meaning that the farther a galaxy is from the earth the greater its speed...