An introduction to engineering adapted from the course “What is Engineering?” offered to freshman at Johns Hopkins University

What is Engineering?

What is Engineering?

How does it differ from science?

Science:DESCRIBEEXPLAIN

Parameters: θ, Ψ, ρ, σ2,☺,λ, Ǻ, g, ћ, H2C5OH, . . .Starting salary: $38K (chemist)

Engineering:INVENTDESIGNBUILD

Parameters: $Starting salary: $54K (chemical engineer)

iPod

spandex

If it moves, it's mechanical engineering;If it doesn't move, it's civil engineering;If you can't see it, it's electrical engineering;If it smells, it's chemical engineering.

Engineering: What are its fields?Thirty years ago. . .

Today, it’s a blur. . .

Biomolecular-, nano-, computer-, materials-, robotic-, biomedical-, environmental-, . . .

What is Engineering?

According to Webster’s II New Riverside Dictionary:

Engineering is “the application of mathematical andscientific principles to practical ends, as the design,construction, and operation of economical and efficientstructures, equipment, and systems.”

But is there more. . .?

“Engineering. . .to define rudely but not inaptly is the art of doing that well with one dollar, which any bungler can do with two after a fashion”--Arthur Mellen Wellington, The Economic Theory of Railway Location (1911)

Engineering is art. Aesthetics as well as function counts

The Guggenheim Museum, Bilbao, SpainFrank Gehry, architect

The Ironbridge, Coalbrookdale,England 1779

More art . . .

Pont du Gard, France, 100AD

Sagrada familia, Barcelona

Boring - see Civil Engineers --UK Yellow Pages

More engineering art. . .by women

Vietnam Memorial (Mia Lin)

Hearst Castle (Julia Morgan) Musee d’Orsay (Gae Aulenti)

London eye (Julia Barfield)

Engineering is problem-solving

Engineering is approximation. The mathematics of engineeringsystems are often too complicated to solve analytically.

“Engineering problems are under-defined, there are many solutions,good, bad and indifferent. The art is to arrive at a good solution.This is a creative activity involving imagination, intuition, anddeliberate choice.”--Ove Arup

Engineering is measurement and estimation. River flow,noise in a communication system, scatter in a laser beam,earthquake characteristics--all require measurement

Engineering is modeling and simulation.

Often the only efficient means to confirm that an idea or design will work is to experiment with a scale model or computer simulation.

Model of the X-33 being testedin the NASA Langley Mach 20helium wind tunnel

Engineering is communication. Making presentations,producing technical manuals, coordinating teams for largescale projects are all fundamental to engineering practice.

Richard Feynmanduring the Challengerdisaster hearings.

$125M communication error

Engineering is politics. The best functional solutionis not necessarily the best practical solution.

Three-mile island

NIMBY

Alaskan pipeline

Engineering is finance. Design, construction, operation,and maintenance costs determine the viability ofprojects.

The Big Dig, Boston: $14.2 billion

The Channel tunnel: $21 billion

($1 billion = 666 Eiffel towers)

Engineering is invention/design/innovation. New devices, materials, and processes are developed by engineers to meet needs that existing technologies do not address.

Engineering is ethics.

Engineering is safety.

Engineering is public service.

. . .

“Architects and engineers are among the most fortunate of men since they build their own monuments with public consent, public approval and often public money”--John Prebble

Engineering is new materials. . . and the space elevator

Engineering is new designs for old problems

Millau viaduct-France (2005)

Engineering isn’t only about big things.

It’s also about nano-bio, bottom-up, tailored structures

quantum dotbiological markers

SWCN switches nano-robots

Engineering is haptics and robotic surgery

Engineering is acoustic control

Expose yourself to engineering!

What is learning?

Synthesizing theory and knowledge in order to solve problems:

Not just theory out of context--the “what”. But also the “why”,“when”, and under what conditions the theory may be invokedto solve a problem.

Learning is also discovering what doesn’t work.

". . . a failed structure provides a counterexample to a hypothesis and shows us incontrovertibly what cannot be done, while a structure that stands without incident often conceals whatever lessons or caveats it might hold for the next generation of engineers." Henri Petroski, To Engineer Is Human

Best educational technique: Apprenticeships

Graduate-student training

Medical residency programs

Plumber’s apprenticeships

Music lessons

Learn by doing!

Best educational strategies in a classroom

1) Provide context--give reason to understand a theory or calculation

2) Give problems “out of the chapter”

3) Give assignments that involve efficiency, cost, functionality, accuracy

Best educational strategies in a classroom (cont.)

4) Back-of-the-envelope problems: “Fermi questions”

5) Assignments without single, deducible, correct answers

6) Taking data and deducing the underlying physical principles

7) Hands on--laboratories, virtual laboratories, projects

Engaging the students

• Do’s– Introduce each topic or subtopic by posing a problem

• Suppose we need to devise a robot that moves toward light. . .

• Suppose we want to separate fat from gravy for a Thanksgiving dinner. . .

• Suppose we want to bid on a tree as material for a toothpick factory. . .

• Suppose we need a bridge to support the weight of a car. . .

• Suppose we would like to deduce the period of a pendulum. . .

– Continually ask “why”• Why do we want to do this?

• Why do we care?

• Why digital instead of analog?

• Why binary instead of decimal?

Engaging the students

• Do’s (cont.)– Ask the complementary question “Why not?”

• Why not use Elmer’s glue (or a glue gun) on spaghetti bridges?

• Why not measure the weight of a single penny on a postal scale?

• Why not use titanium to build bridges?

• Why not

• Do’s (cont.)– Ask “what?”

• What tools/principles can we use on this problem?

– finding forces in members attached to a pin joint on a stationary structure

– separating alcohol from water

– improving the accuracy of a measurement

• What are the conditions under which XXXX will/will not work?

– Can we have a stone lintel that spans 20 feet?

– When will a model yield characteristics of its full-scale counterpart?

– What does it mean if the mass entering a control volume does not equal the mass leaving a control volume?

Engaging the students

• Do’s (cont.)– Give examples and counter examples

– Give reasons for each step in solving a problem (the solution is less important than the strategy for approaching it)

– Pose sub-problems, i.e., “what if?”

– Relate to other fields

• mass conservation vs. Kirchoff’s laws

• heat flow vs. electron flow vs. particle diffusion (gradient transport)

Engaging the students

• Don’ts– Don’t present theories/calculations without context

– Don’t use ambiguous or loosely defined terms

– Don’t “plug and chug” problems (maybe it’s OK occasionally)

– Don’t present topics without placing them within a “bigger picture”

Engaging the students

What is Engineering? The course.

From a fundamentals point of view:

1) Dimensions and their role

2) vs. 3.1416 and dx vs. x

3) “Stuff” is conserved

4) Zero as a condition, e.g.,

5) NAND gates rule the digital world

0forces

What is Engineering? The course.

From a substantive point of view:

1) Strength/behavior of materials2) Statics/structures3) Uncertainty, statistics, measurement4) Robotics5) Digital logic/circuitry6) Separation processes7) Diffusion, heat transfer

From a “process” point of view, i.e., what an engineerdoes

1) Communicationa) proposal presentationb) development of assembly/construction plansc) reporting and interpreting of laboratory resultsd) research synthesis (written)

2) Project managementa) time/team managementb) designc) constructiond) testing

What is Engineering? The course.

“process” (cont.)

3) Experimentationa) measurementb) application of principlesc) application of data

4) Toolsa) approximationb) statisticsc) computer software

i) simulationii) spreadsheet/presentationiii) graphics/drawing

What is Engineering? The course.

1) Properties of materials

2) Materials laboratory

3) Theory of structures

4) Design a bridge to specification

5) Build it

6) Test it

0,0,0,0 zyx FFF

What is Engineering? The project.