innie/outie?

In reference to:

A long time ago, a nurse told me that if you tie the umbilical cord right-handed, the belly button will tend to be an innie. If you tie it left-handed, it will tend to be an outie. This is because a clockwise force produces an inward torque. ("Righty-tighty, Lefty-loosy and all).

On the other hand, she might have been pulling my leg.

I have not found confirmation elsewhere though.

Without using any source of information other than what comes to mind, i would have to say i vote she is pulling your umbilical cord. The only reason righty tighty and lefty loosy works is because of the direction of the threads on the screw.

But look up “torque” and “right hand rule.”

http://www.physics.uoguelph.ca/tutorials/torque/Q.torque.quiz.one.html

This would only be of importance if you actually, you know, tied an umbilical cord. Which you don’t. :wink:

Speak for yourself! :cool:

Yeah, well… :stuck_out_tongue:

So when you say you “tied one on,” you really do mean it! :smiley:

Everyone needs a hobby; unlicensed obstetrics is mine. Don’t you judge me!

It’s important to note here that torque is not a vector; it’s what’s called a pseudovector. What that means is that there’s no inherent reason that torques should point the way they do instead of the opposite way: Someone somewhen made an arbitrary choice about it, and we’re sticking with that arbitrary choice. Nothing at all would be different about the world if we had instead decided to define torque using a left-hand rule.

The world would be so much simpler if mlt were to be augmented by θ.

Chronos,

So torque is not real work then?

If it can be arbitrarily defined by either the left- or right- hand rule, I would think it isn’t real work.

All the rotational units should be measured in so-and-so per rotation, or radian, or degree, but some idiot years ago said, “Oh, but angles are pure numbers, so they don’t count.”

There was a time when the same assumption was made about electricity and magnetism, and the official unit for either inductance or capacitance (depending on whether you took electricity or magnetism as primary) ended up as “1 centimeter”. That mess was finally cleared up, but the ridiculous definition of torque as equal to energy still goes on.

Well, that pretty well clinches it then. There isn’t any physical reason why if you tie the umbilical cord right-handed then the belly button will be an innie but if you tie it left-handed then it will be an outie.

Now at least 90% of the population has innies, and about 90% of the general population is right-handed, so dang, I found the story convincing. I would love to see some data from Elendil’s left-handed colleagues though.