X-rays are a form of invisible, high-frequency electromagnetic radiation. X-rays are very small and energetic. They are used in different branches of science.
First World War, also known as the World War I (WWI), was a global war centered in Europe that drew in all the world's economic great powers of that time.
The Taj Mahal is a white marble mausoleum located in India. It was built by Mughal emperor Shah Jahan in memory of his third wife. Find out if you are familiar with some other facts of this world wonder.
Central Russia got hit by meteor shower. It happened as the meteor exploded over the Ural, its pieces burnt in the lower part of the atmosphere but some were still able to hit the small town of Chelyabinsk.