There's been a good deal of hype surrounding gravitational waves recently. It's been all over the news, and has something to do with Einstein as far as we know. Wondering what it all means? Well wonder no more, I'm here to deliver the abridged version of what you need to know! For dummies.
So, what is a gravitational wave? Well, it's a wave that propagates through space-time itself. Remember how space and time are actually one thing, like a quilt over the universe? Well, gravitational waves travel along that plane, stretching and shrinking space itself. And, it acts upon space-time in perpendicular directions, kind of like an electromagnetic wave. In short, it's a transverse wave (think of a sine wave) that acts in two different directions, the horizontal and the vertical.
Now, that may still be confusing, so imagine this. You're standing at the end of a long square hallway with lights all along it. A gravitational wave starts at the other end, traveling toward you, and means business. As it approaches you, you would see the walls and ceiling of the hallway bending in and then puffing out rhythmically. As the walls puff out like they're being pushed in the center, the ceiling and floor get sucked in towards the center of the cross sectional hallway like someone pulled in the middle. Then, the two pairs of sides switch, and the ceiling/floor puffs out while the walls get sucked in. It travels closer and closer towards you, pushing and pulling in time, until it reaches you. At this point it crushes your arms into your torso, rips your head and legs off, then switches and stuffs the top and bottom back on like a hastily saved muffin and pulls your fingers off. Rude.
But, that doesn't mean gravitational waves aren't cool! Check out part two for some more in-depth understanding now that you know what gravitational waves look and feel like!