How do steam trains work?
Like most little boys, and even some big boys, trains are amazing pieces of machinery. Bang came to me to the other day wanting me to look up videos of coal furnaces on steam trains. He wanted to see the coal burning. There were more than enough of such videos on YouTube to satisfy a five year old. Naturally, while watching the coal burn he wondered how it made the steam train chug.
That’s a busy gify. Upon closer inspection you can follow the chain reaction. We’ll start with that bright orange space in the back. The fire. That’s what Bang was originally fascinated by. The heat from the fire is carried through the boiler – the long, horizontal, yellow section. The heated pipes boil the water which rises into the dome at the top. As more and more steam rises it also rises in pressure. The pressurised steam then travels down to the piston. The piston opens alternating sides of a chamber. This alternation moves a larger piston which is connected to a shaft that turns the wheels. It’s this step that give the steam train its signature chugga chugga chugga. The steam is then released from the chimney.
Why are clouds white?
I didn’t really have an answer for this one, right away. I was stumped and had to admit that I didn’t exactly know. I know fog is white, too. But if water is clear, air is clear, why are clouds white? It turns out it’s because of the size of the droplets of water clouds are made of and how sunlight reacts when it goes through said large drops. Do you know what a micron is? It’s 1,000th of millimeter. A droplet of water in a cloud measure about 10 microns. This is HUGE compared to the rays of light passing through it. Like a hotdog down a hallway huge. The light gets scattered, but because the drop are so huge all the light gets scattered equally. When you mix all the colors you get white. So clouds are white because light is white.
What’s for supper?
Seriously? I don’t know. Unless I’m in the mood to make spaghetti/lasagna sauce, I sometimes don’t know what’s for supper until about hangry o’clock. This morning I ask Crash what he wanted for supper and he said McDonalds. I said, “Nope, I’m cooking.” So he suggested shepherds pie. Unfortunately, we just had something similar last night so I made him pick again. He offered pork roast but I had to shoot that down because we’re cooking for DW’s mom’s birthday on Sunday and we might be having that then. The fourth try was tacos. We had taco Tuesday on Friday. Picky eater Bang doesn’t eat tacos. He requested scrambled eggs, toast, and bacon. I put on my short order cook hat and we all got what we wanted. Yummm…
Where are stars?
In DW’s eyes. There’s some on the Hollywood Walk of Fame, too. There are also billions of them in the sky and this is what Bang was referring to as he gazed out of his bedroom window at bedtime this evening. All of the stars you see are in our very own galaxy, The Milky Way. Looking at the night sky, distant galaxies will be confused for a single star. There’s only one star in our solar system – the sun. The nearest star to our sun is called Alpha Centuri. This is actually a 3 star system even though it looks like a single star in the sky. It takes light travelling at 186,000 miles per second four and half years to get here. If it were to suddenly explode we wouldn’t know it until 2021. For the stars even farther away, we see even older light. To compare, the galaxies photographed in Hubble’s Deep Field photo are roughly 13 billion years old (which is also the shelf life of Twinkies). Earth is only 4.5 billion years old so those distant galaxies are 3 times older than our planet! Incredible!