 Over a century ago, a physicist by the name of Albert Einstein proposed the idea of gravitational waves. And recently, these gravitational waves proposed by Einstein's theory were discovered. But what exactly are gravitational waves? Space and time can be thought of like a pool. Just like how water can ripple sometimes, space and time is also filled with these water-like ripples. And we call these ripples in space-time gravitational waves. But what exactly causes the strange phenomena of gravitational waves? Einstein's famous general theory of relativity states that matter can warp and distort the fabric of space-time. Moving objects can radiate waves of gravitational energy called gravitational waves which can ripple throughout space-time, as mentioned earlier. However, it's not just moving objects that can cause gravitational waves. A phenomena where two black holes collide would also be powerful enough to send gravitational waves rippling through all of space and time. Ok, so now that we know some phenomena where gravitational waves can occur, what are gravitational waves made out of? Think of space-time as an ocean. And sometimes in this ocean, waves can occur. And what exactly are these waves made out of? Water! Gravitational waves are nothing but pieces of weirdly warped space-time. And according to Einstein's general theory of relativity, gravity is nothing but the warping of space-time. So basically, gravitational waves is nothing but pieces of gravitational radiation. However, if you're looking for the answers that pertain to quantum mechanics, then I'll just say simply that gravity is made up of these hypothetical particles called gravitons, which I will not be explaining in depth. But if you want to know more about them, then go check out my other video on gravitons. So basically, the particles that make up gravitational waves, or in this case, the hypothetical particles that make up gravitational waves would be gravitons. Last but not least, what happens when gravitational waves come into contact with an object such as the Earth? Well, the object, which in this case is the Earth, would be stretched and squeezed by the gravitational waves since gravitational waves stretch and squeeze space as they pass by. However, the stretching and squeezing as illustrated earlier is very exaggerated. In real life, Earth is only stretched and squeezed by a very small amount, smaller than an atom. But this didn't stop the LIGO team from detecting gravitational waves, so hats off to LIGO. And now you know what gravitational waves are. Don't forget to like, share, and subscribe. And check out some of my other science videos. And stay tuned for more science videos.