Eli5: when traveling on a boat going 40 mph, how can a bee hover with the boat if it wasn’t already in motion?

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I get that when you throw a ball in the air while traveling, it will go up at the same speed you’re moving at, but for a bee to be going on about it’s business like it’s nothing, traveling at 40 mph.. it doesn’t make any sense

In: Mathematics

11 Answers

Anonymous 0 Comments

When an object moves through a fluid (could be either gas or liquid) the stream moves along with it.

Think of it this way (ELI5ed) – you move your hand through the air, the air molecule that is very adjacent to your hand is dragged along with it (Non ELI5 – in Fluid Mechanics this is called the non slip condition). Now the air molecule adjacent to THAT molecule is dragged along as well, but slightly less since it does somewhat slip. As we move along our imaginary wall of molecules, each one ever dragged slightly less we get a sort of curved shape line, or rather we call it “profile”. This profile is the boundary layer of air that moves along us as we push onward with our hand.

Now lets get back to our bee – our boat is big, and it also moves quite fast this will typically mean that it has a large boundary layer and so our small bee friend is pretty insignificant in terms of disturbing our stream and simply get carried along it, if it hovers (or rather, fly a little forward) close to the ship it will get carried away with us, since the air is also moving (although a bit slower than the boat). If it will fly upward it will disengage from our stream and so the air it experience will be slower and in pace with the regular air around us