Wonders of the Universe

Our time on Earth is precious and fleeting. The most important use of this time that we can make is to ask questions about our wonderful universe, so that perhaps one day one of our descendants will truly understand the natural laws that govern our cosmos.
‘Somewhere, something incredible is waiting to be known

It began 13.75 billion years ago with the Big Bang, and in this embryonic period, known as the Primordial Era, the Universe was a place without the light from the stars, although in its early years the swirling hot matter would have glowed as brightly as a sun

This means that there is a difference between the past and the future: the past was more ordered and the future will be less ordered, because this is the most likely way for things to play out

the First Law of Thermodynamics, which is a statement of the fact that energy cannot be created or destroyed; it can only be changed from one form into another

For all the accuracy and precision we have achieved in keeping time, we have never managed to do anything more than observe it. From the very earliest solar calendars to the electrons jumping around in caesium atoms, one thing about the nature of time is clear: we can measure its passing, but we cannot control it

The Dutch astronomer Christiaan Huygens invented the first pendulum clock in 1656, and it remained the most accurate way of telling the time until the 1930s

Time keeping was elevated to a completely new level of accuracy with the invention of pendulum clocks

The technique of using the flow of water to measure time may date as far back as 6000 BC, but the oldest physical evidence of a water clock can be found in the reign of Pharaoh Amenhotep III in 1400 BC

Sundials are surprisingly accurate, but they have limited use as timekeepers, not least because they are difficult to use on a cloudy day and impossible to use at night!

Travelling at 108,000 kilometres (67,108 miles) an hour, we move through space in orbit around our star. Racing around the Sun at an average distance of 150 million kilometres (93 million miles), we complete one lap of our 970-million-kilometre (600-million-mile) journey in 365 days, five hours, 48 minutes and 46 seconds, returning regularly to an arbitrarily defined starting point. As we sweep through this place in space relative to the Sun, we mark the beginning and end of what we call a year