Story 1 begins — candidate dark galaxy in Perseus

1:17So, we're going to begin today with an astrophysics story about dark matter. As we mentioned, specifically, scientists think they've found a really good candidate for a dark galaxy. This is a galaxy almost completely made up of dark matter, no normal matter. That could give us a little bit of a hint into what dark matter actually is, which continues to be an enduring mystery. So let's dive in on what the story is about. >> Yeah. I mean the central question that almost every cosmologist is trying to answer is what is the universe made out of? Okay. The current paradigm is

1:57something called lambda cold dark matter. This is the model for what our universe is. >> The normal atoms that we see are only about 5% of everything in the universe. It turns out that 24% of our universe is something called dark matter, which we have no idea of what it is. All we know is that it is like matter in that it interacts with gravity, but it's not like matter in that light does not care about it. The electromagnetic field does not care about it. So, it's not so much as dark as it is transparent in every sense of the word. Like a light beam will just go through dark matter and not interact with it at all. This is very weird because atoms love interacting with photons, right? Because they're

2:39electrically charged. >> Obviously, electromagnetism is a thing. And then finally, there's about 72% that is like dark energy, which we're not even going to get into this time. But just just to set the stage, right? Like we only we only know what 5% of the matter is in our universe. >> That's pretty pretty insane. >> I can you just repeat that really quick?