Physics is so dear to me, although many students and science teachers alike do not feel good with it. To some, it is boring and full of Maths. Others just do not find it attractive to their intellect, I should say. But to me, it is full of wonders and an endless chain of discoveries. One of my favourite topics in this field is Space and the Universe. It appeals to me differently because I feel like watching a movie and doing some reflection at the same time.
Just like the stars that we glimpse in the sky on quite nights, they are full of excitement. They are part of the history that unfolds before our senses, because the stars that you see were actually there many years ago. Stars are light years away from the Earth, and so it would take years for its emitted light to reach us. A light year is a distance that light can travel in one year. If a ray of light travels in a vacuum in approximately 3×108 m/s, the ray of the sun which distance from the Earth is approximately 150 million kilometres could reach the Earth in eight minutes, how much more for distant stars? (more…)