Gravity's Terms and Conditions (You Already Agreed)

By having mass, you agree to the following terms. Please read them carefully. You have, technically, already accepted them. You accepted them before you were born, and there is no button to decline.

Clause one, scope. This service applies to everything that has mass: you, your phone, your school bag, the Moon, the ocean and the bit of dust on your screen. It is not possible to opt out. Previous users who attempted to opt out by jumping have reported that the service resumed almost immediately.

Clause two, strength. Near the surface of the Earth, all objects will be accelerated downward at about 9.8 metres per second, every second, if nothing gets in the way. This rate is the same for a cricket ball and a bowling ball. Feathers, paper and parachutes may appear to receive a slower service. This is due to interference from the air, a third-party provider for which gravity accepts no responsibility. The reason the service treats all objects equally is accounted for as follows: a heavier object is pulled harder, in exact proportion to its mass, but it is also harder to get moving, in exact proportion to the same mass. The two cancel. Every object receives the same acceleration, whatever its size, and the service considers this only fair.

Users doubting Clause two are invited to consult the 1971 demonstration on the Moon, where there is no air. Astronaut David Scott dropped a hammer and a falcon feather at the same moment, on live television. They landed together. Clause two stands.

Clause three, weight. Your weight is the force with which this service pulls on you, and it depends on where you are. Your mass is how much of you there is, and it does not. Users who travel to the Moon will find their weight reduced to about one sixth. Their mass will remain unchanged, as will the number on the bill for the trip.

Clause four, range. The service weakens with distance, falling to one quarter of its strength each time the distance doubles. It never reaches zero. The full formula, filed by Isaac Newton in 1687, states that the pull between any two objects is proportional to both of their masses multiplied together, divided by the square of the distance between them, multiplied by a constant of nature so tiny that it took more than a century before anyone could measure it at all. You are, at this moment, being pulled on by every star in the galaxy, and by the person sitting next to you, and they by you. The pull between two people is far less than the weight of a grain of sand, which is why you have never noticed it. No action is required on your part.

Clause five, so-called zero gravity. Users who have seen astronauts floating in the International Space Station may assume the service is unavailable in space. This is incorrect. At the station’s height, about 400 kilometres up, the service is still running at about 90 per cent of its strength on the ground. The station and its crew are falling towards the Earth constantly; they are simply moving sideways so fast that they keep missing it. Everything falls together, so nothing pushes against anything else, and the users float. This is called being in orbit. It is also called falling, with very good aim.

Clause six, shielding. There is no material, coating, umbrella or app that blocks this service. Advertisements claiming otherwise should be reported.

Clause six and a half, tides. The Moon and the Sun also provide this service to the Earth, and because the service weakens with distance, they pull slightly harder on the side of the Earth nearest them than on the far side. The oceans respond by stretching into two bulges. Users who live by the sea will receive two high tides on most days, at no extra charge.

Clause seven, changes to these terms. These terms were last updated in 1915, when Albert Einstein described the service not as a force pulling things together but as the bending of space and time by mass. Users noticed no difference in their daily experience. The service continued exactly as before, and continues still. Thank you for falling with us.