A Spherical Cow In A Vacuum - Why Scientists Simplify ThingssteemCreated with Sketch.

in #steemstem6 years ago (edited)

Nepluno link CC BY-SA 4.0 license

STEM (Science, Technology, Engineering and Mathematics) is hard and the first attempts to explain a phenomenon often fail if one tries to solve the entire problem in the first go.

The Example Of An Artillery Shell

For instance, take the relatively simply problem of modeling the firing an artillery shell at a target. How do you do this?

To do this successfully we are also going to have to account for all of these effects:

  • Air friction,
  • Air turbulence,
  • Coriolis force,
  • Different air pressures at different elevations,
  • Wind speed,
  • Different wind speeds and directions at different elevations,
  • Variations in the gravitational field at different heights above the ground,
  • Wobble in the artillery shell,
  • Variations in the strengths of the explosive charges,
  • Change in position of the target,
  • Change in velocity of the target,
  • Change in position of the artillery piece (i.e. if the gun is on a moving battleship or a moving tank),
  • and much more.

That is a lot to consider and if you try to incorporate all of these effects in your first artillery model then you are going to have a bad day.


Ingrid Kallick link CC BY 3.0 license

Instead you would first start by assuming that the shell is being fired in a vacuum. This will eliminate the air friction issues, turbulence issues, wind speed issues and issues with changes in air pressure.

Now all you have to worry about is the gravitational field, the shell's initial velocity and the position and movement of the target.

That should be a more tractable problem. Once you start getting fairly good predictions out of your calculations with this simple model then you would add more factors, one a time. The first would likely be Coriolis effects as it is fairly easy to predict and calculate. Following that, adding in the gun's velocity (if it were on a ship or moving tank) could be a good next step.

Then after that you might add in a simple air friction model without any turbulence or changes in air pressure with elevation. In this model you would assume that the shell is not teardrop shaped but is instead cannonball shaped (our spherical cow). This will eliminate wobble and many aerodynamics effects.

After that problem gets solved then you might add in the shell's shape and turbulence and you would be close to a good final model.


Pixabay.com link CC0 license

The Atom

The atom is another good example of being first simplified in order to understand it. The first atomic model assumed that it was indeed just that, an indivisible sphere.

At first the atom was considered to be a simple, indivisible unit (a sphere).

Then the existence of electricity was proven and the inference that electrons existed also happened. So the atom was next modeled as a simple solar system with the heavy nucleus in the centre being orbited by the requisite number of electrons.

Then science figured out that the nucleus could be split so the first concept of the nucleus was just a simple 'teardrop' model composed of a proton-neutron soup.

Later quantum mechanics was developed so the solar system model of the atom had to be dropped and replaced with orbitals (i.e. electron clouds) in which the electrons had no definite positions but were waves and they only had probabilities of existing in any given place.


Ridwan Jaafar link CC BY 2.0 license

Closing Words

The examples are many and each field in STEM has it own set of spherical cows.

Simplification is a necessary and indispensable first step in driving towards an understanding of any new phenomenon or object.

Cows are not spheres but it is always a good idea to assume that they are until you can get a good handle on their true "cow-ness".

Thank you for reading my post.
 
 
 

Post Sources

[1] What Is Up With The Spherical Cow?
[2] What Does the Term Spherical Cow Mean?
[3] Spherical Cow: A Simple Model..
[4] XKCD: I don't get it. Somebody 'splain please?"
[5] The Atom - Wikipedia Article..

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Yeah, the whole God particle thing is kinda cringey.

The other one is when they abuse the term "holy grail" as in "the theory of everything is the holy grail of physics".

Sigh, science isn't a Raiders of the Lost Ark movie.

Another example from outside Stem: learning Chinese. If right from the start you decide you're going to go native and learn tones, grammar, vocabulary, and the written characters all together, it's all a bit much and most people just quit in frustration. instead it is better to make the cow a sphere and pretend that Chinese is actually written using phonetic English (pinyin). Then you can feel like you're actually making a bit of progress ( until you attempt the characters again six months later)

Chinese looks daunting, from the very large character set to the intonation issue for words. Too big of a barrier for entry and might be why the planet is adopting the more forgiving English.

Udderly wonderful article!

Wow if they should look simplify because with so many points it is difficult to move forward.

That is a lot to consider and if you try to incorporate all of these effects in your first artillery model then you are going to have a bad day.

You can actually try all #winks..... Having a bad day is not a bahd idea

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