Bernoulli had a lot of time on his hands (another reason why I know he wasn't a mom), or at least enough time to develop theories and equations to describe fluid flow. To sum his findings up quickly, Bernoulli's equation states that as the speed of a fluid flow increases, its pressure decreases. And in related news, as the area that a fluid flows through decreases, its speed increases.
Why did I have to know all of this? Because my field of study happened to be aeronautical engineering, and because the Wright Brothers were the first ones that tried applying Bernoulli's Principle to predict lift on an airplane wing. (As you might have heard, they were successful!) So anyway, Bernoulli and his equation quickly became one of the cornerstones of my studies.
How does Bernoulli's equation help explain how those huge 747's stay in the air? It goes something like this:
Most wings on airplanes are designed so that the top of the wings are curved, and the bottom of the wings are essentially flat. As air splits around a wing, the air flowing over the upper curved surface of an aircraft wing moves faster than the air beneath the wing, so that the pressure underneath is greater than that on the top of the wing. This pressure difference results in a force called lift, that then pushes the wing upward.
Now the truth of the matter is, that Bernoulli's equations alone doesn't completely explain how a plane flies. There is actually no one equation that is going to simply explain it, because it's not a simple phenomenon. Another guy you may have heard of, Isaac Newton, appeared to have lots of time on his hands as well (again, clearly not a mom). And he came up with additional equations and even LAWS that play a part in explaining how we now have the option of flying to Disneyworld in a matter of hours, as opposed to having to drive there over several days in a minivan with the kids in the back whining, "Are we there yet?" (THANK YOU, Mr. Bernoulli, and Mr. Newton!).
But even though using Bernoulli and his equation to explain airflight oversimplifies things a tad, you can still be a hero to your kids the next time they ask, "How do planes fly?", and you can have a scientifically substantiated answer ready for them. And if that's not enough, if one of your children wants to learn how to throw a curveball someday, Bernoulli can definitely help you there.
The key to throwing a curveball, is to throw it so it spins while its traveling forward. Not spinning end-over-end, like it's rolling through the air... but spinning around its middle, like a mini flying merry-go-round.
As air flows around the ball, the spin of the ball cause the air to slow down a little on one side and speed up a little on the other. The side where the air speed is higher has lower pressure, so the ball veers in the direction of the lower pressure and curves as it flies towards home plate.
Now, I can explain the science behind a curveball, but that doesn't mean I can throw one. I'm hoping that when my boys get bigger, they'll take after their dad in terms of athletic prowess. If they're interested in the mechanics behind it all, I'll be happy to chat it over with them. But in the meantime, I can entertain them by making a mean paper airplane.
Take for example, the timeless struggle at the dinner table. You've spent and hour or so creating a nutritious, delicious, well-balanced meal for your family. You've dished up a reasonable amount of everything on each plate, enough to cover the basic food groups, but not too much to overwhelm the smallish appetites of the younger ones. (Well, maybe your younger ones have smallish appetites. Truthfully, the two smallest members of our family can outeat most grown men... but I digress). But after all your hard work, and considerately-sized servings, it never fails that one member of the family will take offense to at least one of the lovingly homecooked dishes on his or her plate. (If the disagreeable one happens to be your husband, than that is simply an issue we will have to address on another day... but assuming the one giving you trouble is one of your children, continue on).
Throughout the meal, small amounts of encouragement may be given to this hold-out, in hopes that the progress will pick up a bit and that the meal will be finished. As the other plates on the table start to clear however, a more stern pressure may be applied, and flat out commands like, "Finish your peas!", may start to be issued. Eventually this usually escalates to something of the order of, "Finish your peas, or you can sit there all night for all I care!!" But by the time everyone else has completely finished their meals, even after secondary trips to the bread basket, it becomes clear that progress being made by this particular family member has stalled out completely.
So what would Bernoulli do? (WWBD?) Well, Mr. Bernoulli tells us: as pressure increases, speed decreases. This certainly seems to hold true in child/parent power struggles. The more insistent you are that the peas be eaten, the slower it seems the peas are actually consumed. So, what to do? Release the pressure. That's right, instead of burying the needle of the pressure gauge over in the red, just let up, and let it drop right off the scale. But along with it, also let go of the interaction that has been going on between you and the stubborn little monkey. Because, as most of us moms realize, it's never so much about the peas, as it is about the attention that is being paid to him or her because of the peas.
So it goes something like this: "Okay, you stubborn little monkey, (or you can use the child's actual name if you're from one of those polite families), take your time and finish your peas. But the rest of us have to move on to the next activity of the evening. When you're done with your peas, you can come join us!" And then, walk away.
Admittedly, the success of this approach relies heavily on the attractiveness of this other activity. Just as assumptions are made in the traditional application of Bernoulli's Principle (the flow is steady, the fluid has constant density, there is no friction, blah, blah, blah), assumptions are made here that the after-dinner activity isn't something horrid like a family trip to the doctor to get flu shots. But even if the next activity of the evening is cleaning the garage, it's eventually going to seem much more appealing to be out there with a broom and dustpan and the rest of the family, as opposed to sitting alone at the table with nothing but a handful of peas for company.
With the pressure released, you'll be surprised at how quickly the struggle can evaporate and the speed with which the meal can be finished. But just as Bernoulli alone may not explain how that plane gets in the air, this approach alone may not make every pea disappear... but it will most likely cut the struggle short, and make throwing a fit much less appealing next time.
So instead I will share with you my favorite all-time use for ketchup, and it doesn't involve Bernoulli or his Principle at all:
Magic Meatloaf Sauce
I think my sister first learned how to make this sauce in her Home Ec. class in junior high. Maybe it was high school, I don't exactly remember, but I know my sister was the source. She started stirring it up on the stove, and it looked average enough... but that night we put a bit on our meatloaf, and it was fantastic! My family flipped out over it, and we never had meatloaf without it again. My dad made sure she would make extra so he could use some on his meatloaf sandwich the next day. It's three simple ingredients, but don't underestimate it. It's yummy!
1/2 Cup Ketchup
1/2 Cup Brown Sugar
2 Tablespoons Prepared Mustard
Warm over medium/low heat until it just begins to bubble. Turn heat to low and let simmer for 5 minutes.
There are as many meatloaf recipes out there as there are moms, and I'm pretty sure this sauce will taste fantastic on all of them. (That's why it's magic!) But just in case you need a meatloaf recipe to go along with your sauce, here's a simple one I use at home. Serve with some mashed potatoes, peas, and a fresh green salad.
2 Pounds Ground Beef
1/4 Cup Seasoned Bread Crumbs
2 Tablespoons Worcestershire Sauce
2 Teaspoons Garlic Salt
1/2 Teaspoon Onion Powder
Heat oven to 350 F. Mix all ingredients thoroughly, and shape into a loaf approximately 8x4x2 inches. Place in an ungreased rectangular baking pan, 13x9x2 inches. Bake uncovered 1 hour.
Remove from oven, let cool for 10 minutes. Cut into 1-inch thick slices, and serve with a bit of Magic Meatloaf Sauce on top. Serves 6-8.