Comparison between apples and oranges

[-Cp]

We have all been present at discussions (or arguments) in which one of the combatants attempts to clarify or strengthen a point by comparing the subject at hand with another item or situation more familiar to the audience or opponent. More often than not, this stratagem instantly results in the protest that "you're comparing apples and oranges!" This is generally perceived as being a telling blow to the analogy, since it is generally understood that apples and oranges cannot be compared. However, after being the recipient of just such an accusation, it occurred to me that there are several problems with dismissing analogies with the comparing apples and oranges defense.

First, the statement that something is like comparing apples and oranges is a kind of analogy itself. That is, denigrating an analogy by accusing it of comparing apples and oranges is, in and of itself, comparing apples and oranges. More importantly, it is not difficult to demonstrate that apples and oranges can, in fact, be compared (see figure 1).

Read the rest at:
http://www.improbable.com/airchives/paperair/volume1/v1i3/air-1-3-apples.html

 

[waltky]

Orange groves in Fla. ravaged by disease...

Citrus Disease With No Cure Is Ravaging Florida Groves
May 9, 2013 — Florida’s citrus industry is grappling with the most serious threat in its history: a bacterial disease with no cure that has infected all 32 of the state’s citrus-growing counties.

Although the disease, citrus greening, was first spotted in Florida in 2005, this year’s losses from it are by far the most extensive. While the bacteria, which causes fruit to turn bitter and drop from the trees when still unripe, affects all citrus fruits, it has been most devastating to oranges, the largest crop. So many have been affected that the United States Department of Agriculture has downgraded its crop estimates five months in a row, an extraordinary move, analysts said.

With the harvest not yet over, orange production has already decreased 10 percent from the initial estimate, a major swing, they said. “The long and short of it is that the industry that made Florida, that is synonymous with Florida, that is a staple on every American breakfast table, is totally threatened,” said Senator Bill Nelson, a Florida Democrat who helped obtain $11 million in federal money for research to fight the disease. “If we don’t find a cure, it will eliminate the citrus industry.”

The relentless migration of the disease from southern to northern Florida — and beyond — has deepened concerns this year among orange juice processors, investors, growers and lawmakers. Florida is the second-largest producer of orange juice in the world, behind Brazil, and the state’s $9 billion citrus industry is a major economic force, contributing 76,000 jobs. The industry, lashed over the years by canker disease, hard freezes and multiple hurricanes, is no stranger to hardship. But citrus greening is by far the most worrisome.

The disease, which can lie dormant for two to five years, is spread by an insect no larger than the head of a pin, the Asian citrus psyllid. It snacks on citrus trees, depositing bacteria that gradually starves trees of nutrients. Psyllids fly from tree to tree, leaving a trail of infection. Concerted efforts by growers and millions of dollars spent on research to fight the disease have so far failed, growers and scientists said. The situation was worsened this season by an unusual weather pattern, including a dry winter, growers said. “We have got a real big problem,” said Vic Story, a lifelong citrus grower and the head of The Story Companies, which owns 2,000 acres of groves in Central Florida and manages an additional 3,000 acres, all of which are affected at varying levels. “It’s definitely the biggest threat in my lifetime, and I’m 68. This is a tree killer.”

MORE

 

[editec]

Yup.

Analogies need to be reasonably analogous.

When they are they are effective teaching tools.

When they fail they often fail because the student doesn't know enough about the issue to see the analogy.

Or they fail because the analogy isn't really very good.

Effectively communicating about conceptual issues is hard work.

 

[itfitzme]

Sometimes a bad analogy is used to mislead the audience. *The audience, unfamiliar with what is being described has no way to know they are being misled. *

Analogies are not proofs. *Analogies are descriptive.*

If an analogy fails to show how something works, it does not prove that that something doesn't work.*

 

[itfitzme]

V=A*cos(wt+lx) is a mathematical model descriptive of a radio wave, microwave oven energy, light from a LASER, and the undulating rings of water that occur when a pebble is dropped into a still pond. *

All are analogous in the essential element of consideration, the magitude of the wave at any time, at any point in 1-D space.*

The mathematical description is a model and an analogy. It is not a very satisfying analogy. *

Light, microwaves, and radio waves are identical in that they are all electomagnetic field waves. They are different in what reacts to them and how they interact with other thing. We see light. Microwaves heat water. Radio waves do neither.

Waves of water is a more satisfying analogy, for light and microwaves waves, than the mathematical model.

Still, apples are more like oranges than light is like waves of water in a pond.