When the mass no longer makes the weight

In everyday life we ​​constantly fight against the strict law of gravity and spontaneously make this force the arbiter of the direction of the space around us. It is the direction of our weight that “polarizes” the space in which we move. One could almost say that gravity “stylizes” our space, coordinates it and makes the vertical dimension more important than the horizontal dimension.

Gravity also orients our body, polarizes it

This is especially true for climbers, who don’t feel their weight in the same way depending on whether their feet are resting on a support of the wall or if they’re floating by their hands in a vacuum: “A floating man certainly looks like a standing man , pointed out Ludwig Wittgenstein, but the play of forces within him is quite different, which means that he can act quite differently from the standing one. (1)”

This small volume of space that is not lacking in air

The top fear of mountaineers naturally decreases. The fall “into the void” as they say, although the void that is beneath them – and which they sometimes call the gas – is much fuller than the one above. In short, we don’t call “empty” that which is empty, but that small volume of space (not lacking in air) that climbers can overlook and fall into. From this we see that even our vocabulary is bent by gravity.

Gravity, curvature… This naturally leads us to Einstein. One day in 1907, the future father of general relativity had the idea, which he later described as “the happiest” of his life: he suddenly understood that a person in free fall does not feel his own weight. “She will not feel her own weight,” what does that mean? That if we were to fall in free fall, that is, in real vacuum – in an environment that offered no resistance to our fall – all objects close to us, for example our ice ax, would fall exactly – dixit Galileo – at the same speed as us. We would not see them falling, but floating at the same level as us (…)

Bibliographic source

(1) Ludwig Wittgenstein, Mixed comments (1937), trans. G. Granel, Mauvezin, TER, 1984, p. 44-45. [éd. Poche Flammarion 2002]

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