We all like gravity, right? Course we do. Without it your dinner would float off the plate and you’d have to swim round the room gobbling it up…wait a minute, that sounds fun! Damn you gravity!
Really though, gravity is our friend, and without it none of us would exist.
Along with the strong nuclear force, the weak nuclear force, and electro-magnetism, our friend gravity is one of the four elemental forces that govern the behaviour and interaction of particles, waves, matter, and all that crazy quantum stuff, though Gravity is the only force that affects anything with a tangible substance to it.
Gravity is ubiquitous. Everything with mass has a gravitational force. Even now, as you sit on your beanbag or laze in your hammock (I’m not here to judge), you are exerting a slight gravitational pull on everything around you, just as everything around you is exerting its own pull on everything else.
The greater the mass of an object the stronger its gravitational pull, and because the earth is so massive in comparison, everything on it is drawn to its surface, rather than orbiting yo mama while she’s trying to do the shopping.
Greater than the earth, by many orders of magnitude, is the gravitational pull of the sun, which extends its force of attraction over many lightyears in all directions, even exerting its influence over other stars in our neighbourhood, as they in turn effect our solar system.
So how come this force is so weak? Weak, you say? But Chris, you just told me the earth’s gravity holds everything to its surface and the sun affects the orbits of other stars. That doesn’t sound weak.
Okay, let’s try an experiment. Raise your arms above your head and go “blergle ergle lergle lergle.”
Heh heh heh, you look foolish.
My bad, you didn’t really need to blergle ergle, point is you just beat gravity. By raising your arms in the air you defied the effect of gravity and overcame its force. Cool huh.
Why gravity isn’t stronger is a mystery. Dark energy may be helping to accelerate the expansion of the universe, but along with dark matter there should be enough visible mass to cause gravity to draw everything back to a singularity.
Gravity may also be inter-dimensional, permeating throughout the extra 8 or so dimensions postulated by quantum and string theories, lessening its effect on our observable universe. These mysterious realms are currently inaccessible to us, so we won’t know for sure until Star Trek changes from a sci-fi show to a documentary.
Another fun experiment you can do (I use the word fun very loosely here) is to hold two rocks, a big one and a little one, and let them go at the same time. They will drop at the same rate and hit the ground at the same time, even though one is considerably heavier than the other.
This demonstrates the force of the earth’s gravity. The rocks are being pulled to the surface of the planet, by a singular force which acts in the same way on objects of differing degrees of mass.
Now, I’m not an astrophysicist (yes, I know that’s hard to believe) so don’t treat this like a text book, it’s just a short thought about gravity.
Rock the Quasar x