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“If you, as with all humans since the birth of man, desire change; if the system you want to change is complex and poorly understood, if the change you will accept must be the best available, and if it is constrained by limited resources, then you are in the presence of an engineering problem. If you cause this change … then you are an engineer." - Koen
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Read Heuristics and The Engineering Method - taken from Koen's work which can be read here: link
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What is an engineer?
The word engineer is derived from the Latin:
- ingeniare "to contrive, devise"
- ingenium "cleverness"
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What is the difference between:
- a scientist,
- a technician,
- and an engineer?
A mathematician, a scientist, and an engineer walk into a bar....
On the way back to work, they pass an open office and observe that there is a fire starting in the corner of the room.
The mathematician looks around, observes that there is a fire extinguisher on the wall and walks on. He is satisfied that the problem has a solution.
The scientist grabs his pocket calculator, estimates the size of the room, the amount of combustible material, etc, checks the tag on the fire extinguisher to see what size fire it can handle, and after some calculation, he too walks on. He has confirmed that the problem's solution is at hand.
The engineer grabs the fire extinguisher and puts out the fire while the other two are fooling around.
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The difference between Science and Engineering:
Engineering is applied.
What does "applied" mean?
applied: the difference between "theory" and "reality"...
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4 key components an Engineer must balance:
- Need for change,
- Limited resources,
- Determining what’s best,
- Dealing with uncertainty.
1. Change
Engineers cause change through creation.
- build a dam → change the landscape,
- build a road → invite a housing development
the before/after picture is different after an engineer has been on the scene.
“To identify a situation calling for an engineer, is to identify a situation calling for change.”
ENGR's start at point A, not knowing quite what point B will look like or how they are going to get there… Engineers deal with open-ended problems.
example: The Aswan High Dam in Egypt
11,811 feet long,
3,215 feet thick at the base
364 feet tall
consider before / after… state A – state B.
a.) increased the salinity of the Nile by 10%
b.) led to the collapse of the sardine industry in the Delta
c.) caused coastal erosion
d.) displaced 100,000 Nubians from their home, forced them to adapt to life as farmers on newly created land.
e.) generation of enough hydroelectric power to furnish half of Egypt’s electrical needs.
A→B
The Transition
The engineer is willing to develop a transition strategy, but rarely is given a specific, well-defined problem to solve. Instead, he must determine for himself what the actual problem is on the basis of society’s diffuse desire for change.
.
The Destination
Often "B" changes through the design process
- It takes 5-12 years to build a nuclear reactor during which time presidents change, society changes, etc.
- Automotive industry - First society wants power, then they want safe, then they want small and efficient - "B" shifts around quickly.
.
The Path
The creative process is very seldom a straight line. Most roads you drive on curve and twist, because it’s faster and more practical to go around things like the Grand Canyon than to go “straight” through them.
Walking straight into circles link
by Jan L. Souman, Ilja Frissen, Manish N. Sreenivasa, Marc O. Ernst
Current Biology, Volume 19, Issue 18, 1538-1542, 20 August 2009
Abstract: "Common belief has it that people who get lost in unfamiliar terrain often end up walking in circles. Although uncorroborated by empirical data, this belief has widely permeated popular culture.
Here, we tested the ability of humans to walk on a straight course through unfamiliar terrain in two different environments:
- a large forest area and
- the Sahara desert.
Walking trajectories of several hours were captured via GPS.
Participants repeatedly walked in circles when they could not see the sun. Conversely, when the sun was visible, participants sometimes veered from a straight course but did not walk in circles. We tested various explanations for this walking behavior by assessing the ability of people to maintain a fixed course while blindfolded. Under these conditions, participants walked in often surprisingly small circles (diameter < 20 m), though rarely in a systematic direction."
Moral of the story -
Goals
Imagine a soccer/football/basketball game without any goals, or with a poorly defined goal.... or with players who do not understand what their goal is.
Engineers (and everyone) need clearly defined goals and reference points. It's best to try and clearly define "B" from the start (as hard as that might be) and stick to it. Every project is a failure in the middle, nothing is perfect, but if you stick with your goal, you'll eventually accomplish something.
What is the difference between a technician and an engineer?
- A technician implements a defined change.
- An engineer has to decide what the goal is, and which of the many paths from A to B they should take.
2. Balancing Limited Resources
Resources both define, and constrain solutions.
Solutions must take into account:
- available time
- physical materials
- economic considerations
- political resources
Example Problem:
In 50 seconds, estimate the number of ping-pong balls that can fit in this classroom.
(importance of resources – you only have 50 seconds, you don’t have a tape measure, you don’t have enough ping-pong balls to actually fill the classroom, and then count them)
ping pong balls are 1.38” in diameter,
V = 4/3 pi r^3 = 1.4in^3.
0.74 highest packing density for spheres
Unlike science and math, there are no exact answers in engineering.
Example Problem: What is the exact temperature of this room?
No exact solution - temperature changes with time and space, it's different by the door than by the window, etc.
How many ping-pong balls fill this room? We can quibble about packing fractions, can argue about the ability to crush the ping-pongs or not, not etc. etc.
3. Determining What's Best
Instead of looking for “the” answer to a problem (as does the scientist), the engineer seeks “the most optimal” answer to a problem considering the subjective needs of people and resources available to them.
Not all final states are equally desirable – not all paths are the same.
“best” is a subjective adjective.
Example: – What is the “best” vehicle?
To exist, means it was some engineer’s notion of “best”.
Unlike science, engineering does not seek to model reality, but society’s perception of reality, including its myths and prejudices.
What's best is subjective and relative to the application.
Beer vending machine...
"In a society of cannibals, the engineer will try to design the most efficient kettle."
“best” in science = closest to approximating reality.
“best” in engineering = balance of “wants” to resources/$
What does everyone want?
Engineers often manipulate society’s perceived wants – engineers create what they think an informed society should want based on their knowledge of what an uninformed society thinks it wants.
4. Dealing with Uncertainty
Example: San Francisco’s Embarcadero “Freeway to Nowhere”
– engineers designed the “best” way to move traffic…
highway was abandoned mid-construction because it failed to take into account...
“don’t block my view of the bay”,
“Don’t raise the noise level or density of people or increase pollution in my neighborhood”,
- theoretically a design will work wonderfully, but in practice there is always the possibility of having overlooked some criteria it needed to fulfill.
There will always be doubt about the criteria that are important to society, and doubt about the relative importance of these criteria (is it more important that a car is cheap? Or that is lasts a long time?).
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The principle Rule of Engineering Method: Heuristics.
Heuristics: Vague, non-analytic techniques such as using a rule of thumb, an educated guess, intuitive judgement, or just plain common sense to find an answer.
Heuristics are used in everything from computer codes for checkers games, to identifying hurricane cloud formations, and controlling nuclear reactors.
Example: Chess
An exact, calculated, analytic analysis is impossible. There are no computers which are large enough to calculate all of the possible combinations and permutations of all possible games. To learn how to play chess, you don’t memorize all possible games – instead you go on suggestions, hints, and rules of thumb.
Chess Heuristics:
- Open with a center pawn
- Move a piece only once in the opening
- Develop the pieces quickly
- Castle on the King’s side as soon as possible
- Develop the queen late
- Control the center
- Establish outposts for the knights
- Keep bishops on open diagonals
- Increase your mobility
Heuristics:
- do not guarantee you will win
- often offer conflicting advice
- depend on context
- and change with time
– but “hints and rule of thumb” is often the best that we have.
Artificial intelligence problem solving programming technique:
Instead of using an algorithm containing fixed deterministic steps (move forward 3 feet. stop. turn to the left. move 2 feet. Stop. Extend arm.open hand.take cookie.) The program uses heuristics.
Dealing with uncertainty:Like chess, an engineer starts a project not knowing how the “game” will play out, with an infinite number of possible moves, paths, and outcomes that could be produced, and no way to analytically solve which solution should be taken. In the absence of an analytic solution – the use of Heuristics is an engineering strategy.
Objectives:
1 Understand the technical term “heuristic
2 Develop the engineer’s strategy for change
3 Define “state of the art”
4 State the principle rule for implementing the engineering method.
Heuristic
– “anything that provides a plausible aid or direction in the solution of a problem, but is unjustified, non-provable, and fallible. It is used as a rough guide to discover and to reveal. It is to use a rule of thumb, technique, hint, rule of craft, engineering judgment, working basis, or, if in France, “le pif” (the nose), to describe plausible (if fallible) basis of the engineer’s strategy for solving problems. Each of these terms captures the feeling of doubt characteristic of the heuristic."
1. A heuristic does not guarantee a solution
2. It may contradict other heuristics
3. It reduces the search time in solving a problem
4. Its acceptance depends on the immediate context instead of on an absolute standard.
Comparison:
Scientific law vs. Engineering heuristic.
Inside the box
– set of all problems that can be analytically solved using the laws of science. (theoretically solvable given perfect knowledge and infinite time)
- How hot is the sun,
- How fast will this pen drop
- How much force does it take to break this chair
- etc.
Outside the box – anything else. Questions that cannot be answered, cannot be asked, pseudo questions. (Many scientists believe that no points, such as e and f, exist).
- How much of the world's energy/water resources should each person be allowed to use?
- What is the best color for your neighbor's house?
- Should the Aswan high dam have been built?
Note #1:
Engineers can think "outside the box"
BUT they also understand what is inside the box.
Note #2:
"inside the box" vs "outside the box" questions:
A brand new Wilson Ultra-500 golf ball is dropped from a height of 3m onto a smooth concrete floor. How many bounces before it comes to rest?
A 10 pound 6 month old tabby cat is dropped from a height of 3m onto a smooth concrete floor. How many bounces before it comes to rest?
Personal observation: "Outside of the box" questions frequently involve entities from the realm of the living. If it's dead (rocks, air, falling pens) it's possible to use cause/effect laws to predict behaviors and properties... If it's alive? You cannot analytically predict the whims and wills of what living entities are going to do, or what they want.
A,B,B’,C,D,I – sets of problems that can be solved using a specific scientific or mathematical theory, principle, or law. (set A with problem a = all problems solvable using conservation laws, B problems requiring physics etc.)
E, F,G, H – lie inside and outside of box - set of problems which use heuristics, etc.
Example problem: Create a car
Inside the box component: calculating energy efficiency, power, acceleration abilities etc.
Outside of the box component: Trying to predict and deal with the opinions and behaviors of the people you want to design the car for.
Scientist – considers ambiguity a fatal weakness creating an unsolvable problem.
Engineer - considers ambiguity to be an opportunity for adding creativity and personal expressions to a solution. No such thing as "unsolvable" to an engineer... no such thing as a perfect solution either, but we can always make something that is "good enough", and keep making it just a little bit better each year.
Uncertainty about a solution’s validity indicates a heuristic (rather than law) has been used.
2.Heuristics can contradict one another & still be valid (Unlike scientific theories... For a mathematician, contradiction is even worse than ambiguity).
What’s the best vehicle for a family?
Heuristic A.) large, safe van.
Heuristic B) small fuel-efficient $ saving vehicle
Engineers are able to deal with contradictions.
A and B contradict one another, but they are both useful…
3. Heuristics reduce the search time in solving problems
Some problems are so serious and the analytic techniques so time-consuming (or nonexistent) that a fast heuristic solution is better than no solution at all.
Example: New virus is lethal to the human species on a time scale shorter than the scientific theory can be developed to solve it, the only rational course is to use the irrational heuristic method.
"Better first aid in the field
than a patient dead on arrival…"
the solution on the field does not involve state of the art equipment, or trained doctors – isn’t the “absolute correct analytic solution” to the problem.
Engineers do the best they can, with the resources they have, and in the timeframe the product is needed by.
Engineering is not an “exact science”. You do not hear people using the phrase "exact engineering" for a reason. Engineering does not produce "perfect" solutions because reality is not perfect - there are no perfect houses, no perfect cars, no perfect people (well, maybe there was one? but that's it...)
Unfortunately, most of the problems facing mankind cannot be solved with “exact science”. – war, energy, hunger, pollution – like chess, the problems are so complex and poorly understood that analytic techniques are inadequate.
Heuristics quickly produce “good enough” or at least "better than what it used to be" solutions to all of the analytically unsolvable problems.
"Well, let's see now... let's think this over...
an engineer never says “I don’t know”.
You don’t know exactly what lies ahead, your footing isn’t completely sure, your solution will not be perfect, nevertheless, you “Just keep swimming”.
4. Acceptance of a heuristic depends on the immediate context instead of on an absolute standard.
The validity of a heuristic
does it work, or is it useful in a specific relativistic context?
It isn’t “right” or “wrong”, it’s only an idea...
It's like making cake – is there some absolute "fact" or "proof" about what recipe is correct?
No, there are many ideas out there, and different occasions use different heuristics.
“Criticize by creation, not by finding fault.” – “Criticize by re-design.”
One heuristic does not replace another by confrontation but by doing a better job in a given context.
Science
New scientific theories replace old ones, one theory is considered “wrong” and another “right”. Eternal unchanging absolute “facts” are assumed to exist, and describing these facts are debated and argued over. “prove it!” etc. Old “laws” are replaced by new ones after confrontations and tearing apart credentials and egos.
For engineers, the dependency on immediate context instead of absolute truth is the standard of validity and the final hallmark of a heuristic.
Criticism:
While debating what group project to do, keep in mind... people criticize what they are interested and excited about. Apathetic, uncaring, silence is your enemy - not criticism!
Usually, people aren't against you, they are for themselves.
Before you talk, listen.
Act, don't react.
Question instead of argue.
Suggest something better, instead of criticize.
Never give up, never surrender.
"Our destiny is not determined by the number of times we stumble but by the number of times we rise up, dust ourselves off, and move forward."link -
State of the Art
Set of heuristics used by an engineer to solve a specific problem at a specific time. State of the Art devices are designed to best meet the current needs of the population (life expectancy changes, health needs change, what’s popular changes, and the heuristics – rules of thumb used to address new situations and challenges change. )
How to teach heuristics?
Apprentice system – rules of thumb taught to apprentice in the balck-smith shop, or farmer working with their dad growing up etc. etc.
“The impetuous George Washington was surveying frontier lands by the age of sixteen. By 21, with only a few months of formal education, he could ford rivers, chart mountains, charm legislators, and lead troops. Lord Fairfax wrote his mother that he was, “a man who will go to school all his life.” Washington’s classrooms were the forest, the battlefield, and the halls of government. He never asked what was going to be in the final.”
Education system has evolved from apprenticeships to books and professors. As an engineer, you have to realize that everything does not come out of a book – you need to be unusually sensitive to the physical world around you, and use what you intuitively know as part of your design. Be willing to accept new designs that you are unfamiliar with though. Realize your point of view, see others points of view.
In summary... Engineering has no hint of
- the absolute,
- the deterministic,
- the guaranteed,
- the true.
Instead, engineering fairly reeks of
- the uncertain,
- the provisional
- the doubtful.
The engineer instinctively recognizes this and calls his ad hoc method:
- “doing the best you can with what you've got”,
- “find a seat of the pants solution”
- or just “muddling through”
But... Engineers are able to see beyond the words and symbols in books to the physical realities that they represent.
Engineers are not afraid of an imperfect reality.
Their work makes them one of the principles sources humanity turns to for help, and progress.
Engineers are the ones purifying water, producing energy, creating airplanes, phones, computers, MRI machines and pace-makers. Engineers don't just sit around talking about problems, we go out and actually do something to physically solve problems. The world is different today than 50, 100, or 1000 years ago because of ENGRs.
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Quotes about the differences between scientists and engineers:
Scientists are concerned about the fundamentals of things, whereas engineers are concerned about the application of fundamental knowledge.
"A scientist can discover a new star, but he cannot make one. He would have to ask an engineer to do that." — Gordon L. Glegg, British Engineer, 1969.
A "mad scientist" is an engineer
but a "mad engineer" is not a scientist.
"All engineers are scientists,
but all scientists are not engineers"
“Scientists study the world as it is;
engineers create the world that has never been.”
"Scientists get PhDs;
Engineers get jobs"
- nine out of the 10 are in technology
- STEM-related jobs are growing 60% faster than other fields
Engineers think that equations approximate the real world.
Scientists think that the real world approximates equations.
Mathematicians are unable to make the
connection.
Scientists apply laws to understand nature
engineers apply laws to use nature to serve mankind.
Engineers are practical,
Scientists are theoretical …
The work of engineers forms the link between scientific discoveries and their subsequent applications to human needs."
There is a need for understanding how to prevent coffee from spilling out of a cup while one carrying the cup is walking....
The scientist pores over weeks of papers on fluid dynamics and human biomechanics, homonid gait evolution and spends millions of dollars he begged for in grant money....
The Engineer spends 2 cents and says "can i have a lid for this cup?"
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