Ghez via Skype on March 5th, 2017 at approximately 3 pm. I started the interview by asking her the very basic question of why some stars turn into black holes, to which she replied, “It is all about two things: gravity and internal pressure within the star.” I was aware of the gravity factor but had no idea about internal pressure. She further explained that these two things oppose each other- the gravitational force will try to contract the star and the internal pressure will act outwards. When both of these are balanced out, the star will maintain its size and will neither expand nor collapse. However, if a star runs out of fuel, and therefore continues to lose energy from the surface, the gravity will be much stronger than the internal pressure which will result in the collapse of the star and will lead to the formation of the black hole. She also added that the size of the black hole depends on the point when the internal pressure is able to balance out the gravitational force. There are various types of black holes ranging from 0.00000000000000001 cm to thrice the size of our solar system. The supermassive black holes are generally situated at the centre of galaxies. One such black hole, called Sagittarius A* is situated at the centre of our own Milky way galaxy and has a mass 4.3 millions times the mass of …show more content…
I was pretty excited for this section, because black holes are the most destructive forces in the observable universe and can tear apart even a planet if it comes near to the event horizon. I finally asked her about how time is changed around a black hole. She explained it in detail with a great example that time never changes near or inside a black hole. Suppose, we are entering a black hole and wearing a watch, the time will pass normally on that watch as it always had. Although our watch is ticking at a normal rate, someone else would see a different ticking rate on our watch. This difference in time is explained by relativity and gravity. The movie Interstellar is the first movie in the history of cinema to show time dilation correctly. When Dr. Cooper and Dr. Brand landed on the planet revolving around the black hole, their clock was ticking at a normal rate, but Dr. Romily’s clock was moving much faster. This is what a black hole is capable of. Dr. Romliy spent 23 years on the spaceship whereas Dr. Brand and Dr. Cooper only spent one hour on the