Friday, February 04, 2005

Science, Folklore & Old Wives Tales

It seems that Ms. Begley of the Wall Street Journal is not going to rise to the challenge of our science questions, so, as promised, here are the answers. But I will use it as a learning opportunity for my readers. We are going to examine the difference between science and folklore. And we are going to see how the state of our science educations have been adversely affected by unqualified science teachers.
The question of why women astronauts should not wear underwire bras came about as a result of a piece of folklore passed along by Elaine Larsen, better known as Miss Ta Fire. You need to click that link to get the cast of characters:

Elaine Larsen - The Star & Public Face of the team (Not Your Average Soccer Mom)
Chris Larsen - The MasterMind of the Team
“Sparkplug” Larsen - The Sorcerer’s Apprentice (and The Donald’s Future Boss!)

Chris was giving a group of us an engineering tour of the car when he mentioned some of the safety features built-in. One such feature was designed to prevent the kind of accident that caused "Big Daddy" Don Garlits to lose his sight. That is when Elaine added a piece of female folklore she got from Shirley "Cha Cha" Muldowney, to wit, female dragsters should not wear underwire bras. The problem is that under high acceleration, the ends of the underwire dig into the rib cage creating painful welts in the armpits.
Whether or not Elaine and Shirley understand the science, they understand the pain! So this nugget becomes folklore. Not all such nuggets are based in truth, so those become known as “old wives tales”. Now Chris and his audience of scientifically knowledgeable fans can appreciate the science. This is an example of an inertial force (commonly referred to as “G” force). As the vehicle (dragster or spacecraft) accelerates, the driver’s body is forcing the bra out ahead. Newton taught us that for every action, there is an equal and opposite reaction! The faster the acceleration, the more force is required and the more the bra “weighs”. The more it weighs, the harder it pushes into the rib cage. OUCH!!!

Now if we relate this to science education, the question becomes, Are your kids learning science or folklore?

2) The “heat rises” idea is actually a verbal shortcut to describe Free Convection, one of several types of heat transfer. Others include forced convection, conduction & radiation. Heat transfer by conduction (touching) explains how heat travels from the object at a higher temperature (the iron) and flows to an object at lower temperature (the clothes). The flow of steam out of the iron is an adiabatic expansion of a gas (the steam). You push the button and open a port inside the iron. The steam expands out of the iron through the open port.

3) As to how the Blue Angels fly inverted, Wikipedia has a nice article on The Science of Wings. To fly inverted one must establish an angle of attack sufficient to develop enough lift while using enough “Thrust” (see I didn’t forget you - Lee!) to overcome the drag. So you’ll see they fly with their nose tilted up a bit more when they are inverted! That raises the leading edge of the wing and creates a high enough angle of attack!


Blogger Lee said...

My first guess on the underwire bra was going to be the constricting nature of the wire and the odd changes the body goes thru traveling to and from space. But I figured that was too obvious.


Keep It Simple, Stupid!

9:39 AM  

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