How big our universe really is in Urdu | kainat kitni Bari hai | Door Bini

How big our universe really is in Urdu | kainat kitni Bari hai |
Door Bini

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The whole universe is expanding, which on the large scale means that all the galaxies are flying away from each other. A way to picture this is to think of a balloon with circles drawn on it. As you blow up the balloon, the circles don’t go anywhere, but they get farther apart. That’s roughly what’s been happening in the universe since it exploded into existence about 13.7 billion years ago at the Big Bang
Now, gravity develops when a mass creates a bend in space-time. Masses can be measured by observing a planet’s or star’s motion with respect to other objects the Earth moves around the sun at about 60,000 mph. If the sun were four times more massive, the Earth would move at twice the speed. The same equations work for the stars circling around the center of the galaxy. By measuring the stars’ speed, the astronomers can estimate the mass of the galaxy. This relationship of mass to motion works throughout the universe, as far as anyone knows. This obviously oversimplifies things, but h
Galaxies, being enormously massive, create enormous gravity. The 2 trillion galaxies all together have so much mass that their gravity should be pulling everything back and slowing down the expansion of the universe. The trouble is, other reliable measurements show the expansion is not slowing