What is the Difference Between Scientists and Engineers?

For those in a STEM field, the difference between engineers and scientists may be obvious.  However, for those who aren't in a science-related career, and may not be very science minded at all, the difference becomes more confusing.  After all, both engineers and scientists use the scientific method in their day-to-day tasks, and both more than likely invoke higher-level mathematics like calculus at least on an occasional basis.  There is certainly the stereotypical image of scientists in lab-coats working in clean-rooms, performing weird experiments on mice, and the stereotypical image of engineers wearing hard-hats at a construction site, and looking at blueprints.  While both of these stereotypes are certainly true of some scientists and engineers, the line between the two is actually much more blurred.  There are many engineers, myself included, who perform the vast majority of their work on the computer, and spend little or no time on an actual construction site or around heavy machinery.  Likewise, there are many scientists who don't spend all day in the lab, and actually get more hands-on, overseeing construction projects and performing other various tasks in the field.

One Factor Differentiates Engineers from Scientists: Money

So what is the difference between engineers and scientists?  Both use the scientific method, both use higher-level math, and both can be found in the lab, at the desk, and in the field.  When it really comes down to it, the one defining factor that differentiates scientists from engineers is money.  Cold, hard, cash.

A diagram relating the scale of the universe to the branches of
science to the hierarchy of different scientific fields.  This is a
great synopsis of where different scientific research falls in the
order of things.  CC Image courtesy of Efbrazil on Wikipedia.

A scientist is generally tasked with performing research and collecting data.  There are certainly many construction projects around the world that involve hundreds of scientists, such as the Large Hadron Collider, built by CERN on the Franco-Swiss border, but these projects are tasked with collecting data and studying it.  A scientist's primary goal is to gain knowledge, and revise, disprove, or create new theories to explain our world.  The expense of a project is always of concern to scientists, who often have to fight tooth and nail for grant money in order to fund the experiments they want to perform, but the science is always the primary goal.  Scientists have to make a compelling case to their fellow scientists, university leaders, or politicians that their research is of enough value to society to justify spending public dollars on it.  It is a sometimes thankless job, one that comes under increased scrutiny during tight economic times such as now, and one that does not always provide immediate, direct benefits to society.  The public revels in the achievements of scientists during the boom years, but derides them as wasteful and pointless during a recession.

The Millau Viaduct near Millau, France, is one of the modern
engineering marvels of this century.  The engineering of
materials and design are a direct result of research in
materials science conducted years and decades prior.

An engineer, on the other hand, has the primary task of making money.  Their job, oversimplified quite a bit, is to use the data and theories developed by scientists to create products that both provide a benefit to the public, and provide a profit to the company the engineer works for.  An engineer's job is all about efficiency: Making a car that can eek out a few more miles per gallon. Designing a new assembly line that can pump out more toys in the same amount of time.  Coming up with a new way of running a power plant that converts more of the energy generated into electricity and wasting less as heat.  This is what an engineer does.  The design aspect of engineering is probably what most people think of when they think of engineers, but only a small fraction of engineers are actually involved with designing novel products.  Most engineers exist to improve upon the work done by previous engineers.  For many people this sounds very boring, but for engineers and those interested in the field, it can be quite exciting in an extremely nerdy way.  While life as an engineer does not usually have the glamour of discovering a new sub-atomic particle or searching for life on other planets, finding someone to fund your project is often much easier.  If an engineer can show a company how they can save the company $X million per year, the company will fund it in a heartbeat.  Corporations will always jump at the chance to save themselves money, which helps put more money in the pockets of investors, and over the long term, generally lowers the cost of their product to the public.

Scientists and Engineers Rely on Each Other

Engineers could not do what they do without the help of scientists.  The methods engineers develop to help make things more efficient are more often than not due to some advancement made because of scientific research.  If scientists did not do their research, engineers couldn't do their job.  Even so, corporations have a very difficult time justifying spending more on pure research because the return on investment of such an endeavor may not be realized for a decade or longer, if ever.  Investors want to see their money being spent in such a way that the company becomes more profitable, and their time frame is often only a few years.  This is why scientists, especially those performing basic research, are usually employed by the government, universities, or private companies funded by the public sector.  Engineers, meanwhile, who's work generally results in a quicker return on investment, are employed by public corporations and other for-profit entities.  This is of course not universally true of private and the public sectors, as scientists often work in research and development departments of corporations, and engineers often do public sector work on bridges, dams, and probably most well-known, in the United States Army Corp of Engineers.  

Both scientists and engineers are needed in order to transform a simple hypothesis of how the world works into a fully-functioning product available for use by the general public.  Sometimes that path is more obvious, like the basic research in organic and synthetic molecules that led to plastics, and sometimes it is more obscure, like Einstein's special theory of relativity leading to more accurate clocks (and therefore more accurate position information) on Global Positioning Satellites.  Without the work of scientists, engineers would have no new, novel approaches to problems that result in more efficient, cleaner, cheaper machines.  Without the work of engineers, the work of the scientist would never be realized by the general public and scientific progress could not advance.

Investing in Science Always Pays Off in the Long-Term

The next time you hear a politician lambasting scientists (NASA comes to mind quite often) for wasting the taxpayer's dollars on worthless research, step back and think for a second.  What is that research trying to accomplish?  What are the implications of a successful experiment to the general public?  How could engineers, funded through for-profit corporations, use this research in the future to better society?  What is the likely turnaround time from research to product?  Often these questions are not easy to answer, but thinking about how scientific research could help into the future rather than just about how does this help me now, will give you a new perspective on science and engineering.  As people say, "you have to spend money to make money."  Investing in science now will inevitably lead to a better society in the future.  Cutting spending on science to save some money in this year's budget will end up hurting the budget in future years for many years to come.