Explosions, evolution and energy: favourite Cosmos explainers

Where do deep space probes get their power?

As you are reading this, the Voyager 1 spacecraft, carrying its valuable gold-plated record describing life on Earth, is more than 20.1 billion kilometres away – or 135 times the distance between the Earth and the sun. It is, though, still sending back a faint signal, but how is this possible? Read more

 

What is energy?

Any physics textbook will tell you energy is “the capacity to do work”. But isn’t this definition kind of unsatisfying? It’s a bit like Plato’s definition of man as a “featherless biped” – it’s hard to poke holes in the reasoning, but you can’t help but feel something is missing. Read more

 

Quantum physics for the terminally confused

Does quantum physics melt your brain? First, don’t panic. You’re not alone in your confuddlement. As legendary physicist Richard Feynman said: “I think I can safely say that nobody understands quantum mechanics.” Nevertheless, quantum theory is vital for describing how our world is screwed together. Read more

 

What is light?

Imagine you’re in a park, looking at a leaf on the branch of a tree. We know light bounces off the leaf to your eye to tell you it’s green – but what is light, exactly? Read more

 

The dark side of the universe – a primer

Over the past 40 years astronomers have realised that everything we can see – all the stars, planets and galaxies – make up less than 5% of the entire universe. What is the rest? The short answer is, we have no idea. Read more

 

Quantum computing for the qubit curious

What is quantum computing? Regular computers operate according to strict rules of logic. But tiny quantum objects – such as electrons, or photons of light – can break those rules. Quantum computing is the idea that we can use this quantum rule-breaking to process information in a new way – one that’s totally different from how regular computers work. Read more

 

Particle physics: a primer to the theory of (almost) everything

The Standard Model categorises all of the particles of nature, in the same way that the periodic table categorises the elements. The theory is called the Standard Model because it is so successful it has become “standard”. There are, however, still a few kinks to be ironed out (as well as a couple of whopping omissions). That’s why it is sometimes called the “Theory of Almost Everything”. Read more

 

Where did we come from? A primer on early human evolution

The story of human origins is a messy one. Each bone fragment that’s unearthed or ancient genome that’s decoded adds a new piece to the puzzle – and it doesn’t necessarily make the picture any clearer. Read more