Imagine a lump of iron the size of a tennis ball. Weigh it in your hand. Now let it drop on to your foot. How does that feel? Now imagine an identical object three times as dense. How would that feel if you dropped it? Would you ever walk again?
That metal is tungsten.
As well as being incredibly dense it is also incredibly hard and has the highest melting point of all the elements at 3,422C.
A century or so ago the world had no use for it - it was almost impossible to shape or work the stuff. Yet now we use tungsten to write with, to traverse glaciers, to emit X-rays and to destroy buildings without the use of explosives.
To understand how this happened, we need to understand the competitive forces that have shaped everything in our world, and where better to start than a mystery at the heart of the evolution of life?
For the first four billion years, life didn't actually do much evolving. Organisms were small, simple and fairly rare. Then around 500 million years ago something extraordinary happened - the Mineral records show there was an incredible explosion of life.
An extraordinary array of wonderful new organisms appeared. There are saucer-eyed creatures with tentacles below and an arc of dramatic spines on their backs, there are squids with crab-like arms and strange things like floating air mattresses with a fringe of tiny waving fingers.
Charles Darwin reckoned what is known as the "Cambrian explosion" was the most powerful objection to his Theoretical of natural selection. This abrupt flourishing of species went against the idea of gradual evolution.
So what could have caused it?
Many scientists now believe that this great proliferation of new life was driven by the development of what was, by Cambrian standards, an exotic new capability - theories include the eye, or even the anus.
Or how about teeth? Worm-like creatures with spikes around the entrance to their guts that first appeared during the Cambrian look fearsome even now, but just think what effective killers these predatorial jaws would make in a world of soft, vulnerable organisms.
And that's not all. The Cambrian is also when the shells and exoskeletons first appear in the Mineral record in significant numbers. There is also the first evidence of burrows, of creatures digging into the sea floor.
"It is like finding the disturbing remains of an arms race - swords with shields, guns with tanks, bombs with bomb shelters - in an archaeological dig," the palaeobiologist Martin Brasier has written.
The Theoretical is that the rest of creation had to adapt very rapidly to defend itself, hence the armour of calcium carbonate many creatures threw up, and why some animals evolved to dig themselves to safety.
Biologists call the process co-evolution.
So what has all this got to do with tungsten, you are probably wondering.
Well, the world of manufacturing involves its fair bit of co-evolution. New materials are developed - super strong alloys, for example - which mean something like an aeroplane or an electricity turbine can be made more resilient, and often lighter and cheaper too.
But stronger components require tougher tools to work them - and that is where tungsten comes in. Element 74 in the periodic table is one of the toughest substances in nature.
Tungsten filaments generate the X-rays that give us a view inside our bodies and bones, and also the welds that hold ships, planes and bridges together. It is also used to form the emitter tips of the electron guns that allow electron microscopes to peer down and examine objects as tiny as single molecules.
But it was tungsten's density that earned it its name - it comes from the Swedish tung sten, heavy stone.
It is almost three times as dense as iron, almost twice that of lead and virtually the same as gold.
And, like the proliferation of new species during the Cambrian explosion, all sorts of weird applications have evolved to exploit tungsten's unique qualities.
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