The Science of Oz (sort of), Part 1

Lion and Tortoise, by Eugene Delacroix, 1835. Public Domain image courtesy wikipaintings

Science enriches our lives, broadens our understanding, and encourages us to explore the world we live in. Science can also be a big downer when it comes to magic and myth. Sometimes knowing the science of stories makes them less … well, magical. That is the risk we take in this post. 
Remember way back when I annotated The Wonderful Wizard of Oz? Well, not only did it open up some tantalizing mysteries in the Hidden History of Oz, but it revealed some pretty nifty questions that we can ask of science. It’s pretty amazing what brain-puzzlers science can answer if we can just uncover the questions to ask.

Here are a few of the science related questions that I asked, and found the answers for.

• Dorothy was carried to Oz by a “cyclone”, right?
• How loud would a thunderstorm have to be to make a person deaf?
• How far can a lion jump?
• Why couldn’t the lion run out of the Poppy Field?
• How large was the balloon that Dorothy and the Wizard built? How much could it lift? Could it break a rope, like the story said?

Noisy Weather

Was it really a cyclone?

“A cyclone’s coming!” (Uncle Henry, Chapter 1, The Cyclone)

No. The term “cyclone” is actually a misnomer, as cyclones are defined as an area of closed, circular fluid motion that rotates the same direction as the earth – counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.  Mesocyclones can take place over land, where they are often associated with supercells, which can produce tornadoes.

The term that should have been used is tornado, because tornados appear over land, and cyclones are a distinctly ocean-bound meteorological phenomenon. This error was actually brought up shortly after the printing of The Wonderful Wizard of Oz. Even the chief of the United States Weather Bureau got involved with the situation. Actually, the publishers planned to correct this mistake in the next printing … unfortunately they went bankrupt before the change could be made. The book went to another publisher, and the mistake was never corrected.

“The thunderstorm shrieked so loudly that [Dorothy] nearly became deaf.” (Chapter 1, The Cyclone)

How loud would a thunderstorm have to be to make someone deaf?

I asked a friend of mine who is an electroacoustical engineer this question.

Electroacoustical Engineer – does the research to build hearing aids. (No, this won’t be on the test, and yes, I’ve got some smart friends.)

A Thunderstorm with torrential rain at peak levels exhibited decibel levels of 95-112. This is very nearly deafening. My friend said that it takes 110 decibels for one minute to risk permanent hearing loss. (This is equivalent to the noise of a chainsaw.)

Lions a’leaping

How far can a lion leap from a standing start?

When they came to the chasm on the yellow brick road, how wide was it? What is the maximum width that it could be for the Cowardly Lion to do a standing leap over it?

“Why don’t you run and jump?” asked the Scarecrow.
“Because that isn’t the way we Lions do these things,” he replied. (Chapter 7, The Journey to the Great Oz)

Lions are powerful creatures that can make a 36 foot leap with a full speed running start. However, it is clear that this King of Beasts is going to do things the very proper way. A lion can leap straight up about twelve feet, so they can do a standing leap of at least that far.

Why couldn’t the Lion run through the entire Poppy Field?

On and on they walked, and it seemed that the great carpet of deadly flowers that surrounded them would never end.
They followed the bend of the river, and at last came upon their friend the Lion, lying fast asleep among the poppies. The flowers had been too strong for the huge beast and he had given up at last, and fallen only a short distance from the end of the poppy bed …
(Chapter 8, The Deadly Poppy Field)

This is more question that we can accurately address in this post. Since we’re on the topic of lions, we’ll do that part. How fast can a lion run? A lion can run up to 35 mph for 5-10 seconds.  Another source estimated 160 yards.

35 mph = 51 ft/sec.

So a lion could run about 500 feet at this top speed of 35 miles per hour. If we use this as an estimate, then the poppy field was not “endless”, it would only appear so from their perspective. Even a slight rise in the elevation on the horizon would make it appear as if the field went on and on …

(This issue will be explored in another post. I’ll get some expert feedback on the effect of poppies so we can estimate the size of the field.)

Bags of Hot Air

Could the balloon they made really carry Dorothy and the Wizard back to Kansas?

The balloon was “a big bag of green silk more than twenty feet long.” (Chapter 17, How the Balloon was Launched)

With a sphere estimated at 21 feet in diameter (10.5 feet radius), the volume is 1543.5 cubic feet.

At sea level, heating air to 100 degrees Fahrenheit, it requires approximately 80 cubic feet of heated air to lift one pound of weight.
Therefore, given the dimensions of the balloon: 1543.5 cubic feet, divided by 80 cubic feet for one pound of lift, we find the answer is a stunning 19.29.

The given balloon dimensions could lift approximately 19.3 pounds.

Could the balloon of that size and strength break the ropes?

“The balloon was by this time tugging hard at the rope that held it to the ground” (Chapter 17, How the Balloon was Launched)

If a single rope were ½-inch thick, the breaking strain required to snap the ropes would be 2174 pounds. So the pressure pulling upward on the rope was nowhere near strong enough to snap it.

References:

• How to calculate the Weight of Air and Model Hot Air Balloon Lift.  Here’s the site I referenced to get my numbers for calculation. Feel free to crunch your own version of the numbers.
• “What makes Kansas, Texas and Oklahoma so prone to tornadoes?” (Scientific American, March 28, 2005)

When science disproves magic, which do you believe?

The Wonderful Wizard of Oz is a great book. It’s full of fun and light-hearted magic, but the science disproves some story points. This journey into fairy tale science  illustrates that some things are best left to the imagination.

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