Having Gravity makes writing this a whole lot easier, as the computer is not floating in the air. Or for that matter neither am I, nor is anything else in the room. Newton and Einstein (some heavy weight thinkers indeed) give long answers as to why this is so but the bottom line is this; when I come home and put my keys down, they stay put. Although I will admit sometimes it makes them harder to find than if they were floating in the air.
Another thing to keep in mind is there would be no keys or cars or suns or planets or even a Universe as we know it, without the dynamic (and weighty) attraction of gravity. There would of course be a Universe but no form of any kind. Only Atoms disconnected from each other in thin cloud like shapes, where particles could be millions of miles apart. Making it even more chaotic than the Universe normally is.
As far as gravity goes, the bigger the mass (or weight) of a planet the stronger its’ gravitational pull. What this means is if Earth was twice the size, it would have twice the Gravity and this would make moving around a lot more difficult. On the other hand, we would adapt, but sloths would be really slow.
Subsequently a smaller object such as the Moon has much less gravity. We have watched the Astronauts cavorting about the surface of the moon (yes, they were really there) so we can see this force at work. But on a Terrestrial planet the size of say, Neptune or Jupiter, (which are instead gaseous Jovian planets) our brave astronauts would barely be able to move, much less breathe. Not to mention escaping from the surface of such a planet, would take an incredible amount of energy. And just think how hard a rocket has to work, to escape the gravity on our own planet.
For us here on Earth an additional gravitational consideration is this, the later in the day, the shorter we are. In our fight against gravity we always lose. By that I mean we lose about a half an inch a day. Lying down perpendicular to the Gravitational pull, in order to sleep, allows us to regain our proper height, but every day (especially if you don’t sleep) is a struggle.
Not to mention the ill effects a lack of gravity has on those humans who venture into space. Although the problems get worse during an extended stay, they can appear after just a few days. Floating around the Space Station looks like fun, but your body will quickly abandon the strategies it uses to combat gravity and the problems will commence. Fluids shift, giving you skinny legs and a puffy face. Motion sickness brings on the usual consequences and you become unable to tell up from down and can even lose the sensation of your own limbs.
However this queasiness and disorientation is minor compared to the problems that appear after an extended period of time without gravity. The leaching away of the calcium in your bones brings about osteoporosis. The loss of tone and mass in your muscles is another serious side effect, as is the weakening of your heart because it doesn’t need to work as hard. Of course many strategies are used in order to combat these problems but it still takes some time back on Earth to feel (and be) normal again.
Gravity does bind our Universe and the Galaxies and Solar Systems contained within them together; for which we can all be thankful. As a final note Newton’s famous story of the falling apple awakening him to the idea of gravity’s existence, may be as true as the fable about George Washington’s cherry tree but it makes for a great story. Plus something falling somewhere had to turn the switch on in Newton’s brain so why not an Apple? Why not?