9 November

I think stairs are one of the best examples of our bizarre ideas about gravity. Going ‘up’ stairs is often seen as hard work, people strain to do it, or take the lift. Going down stairs people often fall onto each step, you can hear the clomp clomp clomp as they descend. In both cases the person tries to get to the upwards support of the next stair while they’re still being supported by the stair they’re on. Going up, most of your mass is well above the level of the next step already, all you need to do is shift your support gradually to that next step, rather than try to ‘lift’ your entire body. Going down, there’s no need to shift your mass so abruptly to the lower step, so you fall onto it. You can use the support of the upper stair to gradually transition between the supporting surfaces. Once you get used to gentle transitions in support, there’s no more effort going ‘up’ stairs than going ‘down’ them.