HOW TIME WORKS
From the beginning of the universe to the present day, it’s one of the few things we regard as regular and unchanging. But is it really so constant? We take a look at the physics of time…
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You should probably sit down to read this feature. When considering time, it’s easy to quickly get lost in the complexity of the topic. Time is all around us, it’s ever present and is the basis of how we record life on Earth. It’s the constant that keeps the world, the Solar System and even the universe ticking.
Civilisations have risen and fallen, stars have been born and extinguished and our one method of keeping track of every event in the universe and on Earth has been comparing them to the present day with the regular passing of time. But is it really a constant? Is time really as simple as a movement from one second to the next? We’re about to find out.
13.8 billion years ago the universe was born, and since then time has flown by to the present day, overseeing the creation of galaxies and the expansion of space. But when it comes to comparing time, it’s daunting to realise just how little of time we’ve actually experienced.
DID YOU KNOW? GPS satellites have to account for relativity to remain on time and accurate
Time dilation
What does the theory of special relativity mean in terms of time? We’d suggest reading our explanation of special relativity first to truly get a grasp of time dilation…
The Earth might be 4.5 billion years old, but we modern humans have inhabited it for around 300,000 years, just 0.002 per cent the age of the universe. Feeling small and insignificant yet? It gets worse. You’ve experienced so little time on Earth that in astronomical terms you’re entirely negligible. You would have to relive your life 150,000 times just to match the age of the youngest known star in the universe.