Alok Jha, The Guardian

Think of a cake. When you put it in the oven, it starts off at a particular volume and then, an hour later, it has risen to perhaps double its size. It is obvious what has happened – the air bubbles that you have carefully folded into the mixture during the preparation and the little bubbles of carbon dioxide created by the baking powder have expanded as they are heated in the oven, taking the rest of the cake with it. All this time, the pressure of the air inside those bubbles has stayed the same (you know that because cakes don't usually explode when you slice them after cooking).

You're reading these words because light waves are bouncing off the letters on the page and into your eyes. The sounds of the rustling paper or beeps of your computer reach your ear via compression waves travelling through the air. Waves race across the surface of our seas and oceans and earthquakes send waves coursing through the fabric of the Earth.

Albert Einstein is famous for many things, not least his theories of relativity. The first, the special theory of relativity, was the one that began the physicist's reputation for tearing apart the classical worldview that had come before. Special relativity, a way of relating the motion of objects in the universe, led scientists to re-evaluate their assumptions about things as fundamental as time and space. And it led to important revelations about the relationship between energy and matter.

In the afternoon on New Year's Eve, three dozen passengers from the MV Akademik Shokalskiy walked town the gangplank and stepped on to one of the ice floes that had trapped the ship since Christmas Day.

Icebreaker ships go to help MV Akademik Shokalskiy after captain issues distress call