 Welcome to Super Science Saturday. I am Zeus, God of Thunder and Lord of the Sky. But today, I'm just dad. Because you see tomorrow, it's Athene's birthday party. She's gonna be 3,500 years old. And Neptune and I are preparing a surprise party for her. We got some nice birthday balloons here and some ambrosia and nectar. And we're gonna get it all ready and we're gonna have a good party. All right, let's go. What's going on here? What's going on? Oh, that was weird. The ambrosia fell over, but these balloons, when I started up, they went forward. That's peculiar. Let me try that again. Balloons go forward as I accelerate. And then when I stop, they go forward. One more time, one more time, just to be sure. Okay, accelerate. This is very peculiar. I could figure this out, but I'm gonna talk to my brother Neptune. He's the god of the sea and he knows all about fluids. And something about this reminds me of fluids sloshing back and forth in the tides in the ocean. So I'm gonna go talk to him and we'll figure out this little problem here. Well, here I am on Mount Olympus. Got a coneptune, but since we're in Greece. Hey, Poseidon! It's probably off on a dive trip with Percy Jackson. Poseidon! Hey, Zeus. Poseidon, what's going on? Yeah, I just got back from my afternoon dive. Excellent. I'm good, yes. You got your trident? Well, I had to check the trident at the door. I'm actually heading over to the barbecue. All right, yeah, it's gonna be fun. The theme's gonna be 3,500 years old. Wow, can you believe that? I got a quick question for you, though. Yeah, you know how balloons normally, when I go somewhere, they drift behind me. See, like this. And then like that. Sure, yep. I was in the car and when I accelerated, they went forward. And this was really strange. So, since you're a fluids god and also hydrodynamics and stuff, maybe you could explain just what's going on here with these balloons. Yes, well, you came to the right person, Zeus. Yep. So the thing is that air is a fluid. So it has mass and it has momentum and it responds to changes in density, for example. Okay. And it's a compressible fluid, not like water, which is a fluid and flows, but air actually responds to changes in density, too. Okay. You can squeeze it and everything. So in my car, the balloons went the wrong way. Does that mean air has mass? I thought air was just like this drifty, misty thing that was all over the place, but it has mass and momentum? Yes, it does, yeah. Both of those things. So remember when you're in the car and you accelerate, you feel like you're being pushed backwards. And the ambrosia rolls to the back of the car. Right, yep. And but in actual fact, the car's moving forwards and you feel that force against you, so it feels like you're being pushed back. Okay. So when you start the car, the air actually moves towards the back of the car. The balloons go forward. And the balloons are lighter than air, so they sense the lower pressure and move towards the lower pressure in the front of the car. Okay. Hey, here comes the theme now. Maybe she, welcome to your birthday party and happy birthday. Hi guys, welcome. It's so great to see you. Good to see you too. This is gonna be a great day. We were just chatting about these helium balloons and meteorology and air and stuff and weight. And maybe you could tell us a little more about how this affects weather. Absolutely. You know, we're surrounded by air. It's just the fluid. Then any air that's less dense and more buoyant will go up, like the helium in these balloons, or like hot air and hot air balloon or warm air into a cloud. Any air that's more dense will fall down or slosh out of the upper parts of the atmosphere. So you can have down drafts that slosh out of a thunderstorm and get hit by that cold wind as the storm's coming in. Oh, that could be dangerous. They can be dangerous. They can cause some destruction, but it can also give you a nice cool breeze before rainstorm as it comes in. Okay. Yes. Hmm. So in my car, things were sloshing around. Kind of, how does that work? Hmm. Let me show you. Okay. Just happens I have a bottle of nectar here on the floor. Okay. And you see there's a bubble in the bottle. Right. At the top. And so if I move the bottle forwards, the bubble initially moves forwards because the liquid moves to the back and then eventually it moves back to the middle again. So let's try that again. Move this way. Yeah. See? Yeah, the bubble starts here and then moves back to the middle because the fluid is all getting, the more dense fluid is all getting pushed to the back. So Athena's helium balloons are the bubble. Yes, essentially. Oh, okay, that's pretty cool. That's where they're, they're a bubble in the air. Wow. Well, that's pretty neat. That's a cool experiment. You could do it at home. I like that. Well, I think I smell something in the distance. Maybe the barbecue's ready. I can't wait. Shall we go off to the party? Absolutely. All right. Let's do it. Thank you.