So we start with a question: “How does the Universe look today? Now, to answer this question, we must start with things that are near to us, and gradually expand our look to the vast and immense spaces of the Universe.
To begin with, let’s try if we can see, almost feel, the curvature of the Earth. This has a diameter of almost 13 thousand kilometers. Imagine now a flat terrain with no obstructions. In the distance we can see the top of a skyscraper. If we lengthen this image 70 or 80 Kms, we would be able to see 400 or 500 meters below the horizon, at this point, we have the feeling of the curvature of the Earth. Then, if we raise our eyes, to one hundred kilometres above the Earth, both a cotton swab and a crystal ball move through space, gracefully, at the same speed, free from the earth’s gravitational pull.
At this point, in the blink of an eye, we see the Moon, a second light that is 300 thousand kilometres away. Then, 150 million kilometers or 8 light-minutes away, we find the sun, with a diameter of more than a million Kms, and consumes about 4 million tons per second of its fuel efficiency. In its core, elements boil at 15 million degrees centigrade. Even on the Sun there are rivers, not of water, but of incandescent plasma. They are over 30 thousand kilometres long, and 40 thousand are wide and deep, and run about 140 km / h.