The matter that makes up the stars and galaxies, the planets, trees, rocks, and life all around us - all of this accounts for just 5 percent of the known Universe. The remaining 95 percent is made up of 25 percent dark matter and 70 percent dark energy, both of which are entirely inivisible. And unfortunately, there's not a whole lot we know about either of these things - in fact, the body of knowledge that surrounds these mysterious phenomena is as much about what don't know about them as what we do, as the video above by German design studio Kurzgesagt explains.
Considering that only 5 percent of the known Universe is perceptable to us, this means that reality as we know it, as we experience it, is just a tiny fraction of what's actually going on. And all the rest of it? Well, we're not even 100 percent sure that it really is the result of dark matter and dark energy, but it's the best explanation we have right now, so we have to run with it.
So assuming dark matter and dark energy really do exist, what do we know about them? As the video explains, the first real signs of the existence of dark matter and energy were detected when scientists were trying to figure out how the Universe formed. It quickly became apparent that 'normal' matter couldn't possibly be the only thing involved, because there simply wasn't enough of it. It just doesn't have the gravity to pull everything together into complex structures.
Instead, all those stars that are made from normal matter must exist alongside whatever's filling up the gaps around them - something that doesn't absorb or reflect light, which would explain why we can't see it. Luckily for us, all that dark stuff happens to bend light and interact with gravity, which means we can't see it, but we csn detect its presence where it has accumulated in large amounts. So far we've used this knowledge to figure out not what dark energy and dark matter is, but what it isn't.
I'll let the video above run through what those are, but let's just say we only really know three things for sure about dark matter: something exists, it interacts with gravity, and there is a lot of it. If you want to get a better understanding of these mysterious phenomena in just over 6 minutes, you're probably not going to find a more easily digestible explanation than this. Sure, they've oversimiplified an incredibly complex topic in the interests of accessibility, but for those of you with a little more time and background knowledge, don't worry, we've got you covered too.
Here's an hour of Lawrence Krauss explaining how the Universe came from nothing, and how it will one day return to nothing. You know, some light entertainment for the end of your week. You're welcome.