It might seem strange that a solid substance can bend, but most do to some degree.
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Your leg can bends at the knee and ankle, but that's not a very good example because your leg is a composite of soft and hard tissue, with some fluid in between. And of course there are also joints that allow the bones to move in a controlled way.
Fortunately, bones are capable of absorbing many stresses by being able to bend somewhat.
There are different ways in which a solid material can bend.
Many solids such as metals and certain polymers can be elastic. They bend or stretch under the applied force but return to their original shape once the force is removed.
Beyond that, they can be plastic, where the force causes a permanent change in the shape. That can involve bending, stretching or shearing, depending on the nature of the force and the material's properties.
Many metals are considered ductile because they can be easily deformed without significant bending before reaching their breaking point. Individual atoms or molecules rearrange themselves to accommodate the bending forces.
Composite materials such as parts of your body including bone are made up of different constituents such as fibres embedded in a matrix. The combination allows enhanced flexibility and bending capabilities.
Then there's the curious case of glass. According to some myths, glass slowly droops down the windows of Gothic cathedrals. Apparently the glass is often thicker at the bottom and because "glass is a liquid", they contain ripples.
While that's a catchy idea, it's not true - glass is not a supercooled liquid. It simply means the windows were made that way.
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Even stranger is that glass technically isn't even a solid.
It lacks the highly organised structure of crystals, like sugar and salt, where millions of atoms line up in a row. Glass is actually an amorphous solid, an intermediate state between liquid and glass.
Theoretically, that means glass can sag, but a mathematical model shows it would take longer than the of the universe for room-temperature glass to appear melted.
Now if you're sitting in a dull meeting after reading this column and looking at the window of a neighbouring building, you might see the glass flexing. That could be because someone has opened or closed a door, but it can also happen to a tiny degree when people inside are speaking.
Spies have also noticed this and devised the means to snoop on conversations by beaming an invisible laser to measure deflections in the glass. However it's an unreliable technique because glass is heavy and often double-glazed.
These days it's much easier to tap into the microphones in everybody's pocket.
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