There's more than one way to change the world. Throughout this series, we've seen how different fields in engineering tackle some of society's biggest problems. From medicine to space travel, wherever there's a challenge, engineers are at hand. In learning about these disciplines, you're already doing your part. Whether or not you choose to be an engineer, knowing how they work will help you understand and engage with everything around you. Also, thinking about the world more complexly makes us more informed and considerate about our place in it. So if you think you might want to become an engineer, we can help point the way.

[Intro]

We've covered a lot of ground here on Crash Course. We've seen engineers in action in the fields of civil, mechanical, electrical, and chemical engineering, to name a few. The main thing distinguishing those fields from one another is the problems they focus on and the outcomes they are trying to achieve. But even within a particular field, different engineers will have distinct approaches to tackling the problem at hand. Some come at things from a theoretical perspective, considering the implications of a design or an idea. Others take a more hands-on role, experimenting with prototypes and physical parts to determine their behavior and collect information, which is not to say that engineers are restricted to one or the other, but it's worth bearing in mind that engineering can be done in lots of different ways within fields too.

The process of becoming an engineer can be hard work, so whether you're more comfortable at a blackboard or a lab bench, it's still important to pick a field whose problems interest and inspire you.

Professional engineers are continually learning to keep up with the latest techniques and technology in their field. But, there are some useful fundamentals that apply to all kinds of engineering. Many topics from physics, like thermodynamics, energy, electromagnetism, and mechanics will come in handy. Mathematics will be the foundation of nearly everything you do, and computer programming is becoming an increasingly vital tool as well. Even if you prefer a hands-on approach, a bit of theoretical knowledge goes a long way in finding practical solutions.

Now, to get an idea of the sorts of jobs you might have as an engineer, it's helpful to run through some examples. For instance, consider aerospace engineering. Maybe you're part of a team creating wings for a new airplane. At every stage of the process, different engineers (both inside and outside the company) will have an impact.

Early on, a lot of work will focus on designing and modeling the wings. As we saw when looking at engineering design, before you set out to build anything, you need to know what you want to achieve and then develop a plan that allows you to get there. That's the task for design engineers. Although they're involved at every stage, they have an especially big impact at the beginning, since they oversee the core ideas and details behind the product.

As a design engineer, you'd be working alongside others to determine the exact details of the wings needed to support the rest of the plane. A commercial airline has different weight and speed requirements than that of a fighter jet. So, you might gather inspiration from existing designs for the shape and materials of the wing and where the engines will go.

A key part of being a design engineer is knowing how to balance competing needs and how those needs trickle down into the little details. Throughout the process, you have to consider the cost, energy use, and construction difficulty of each part. Moving a bolt by a few millimeters might seem tedious, but it can have huge impact on how safe or easy to build a plane is.

Of course, to make these decisions, you'll often need to model your design so you can iterate and improve things. And, for that, analytical engineers are essential. Analytical engineers mathematically model and analyze the behavior of designs and concepts. Rather than build an entire airplane wing from scratch every time you want to test some of its features, an analytical engineer would use the toolkit of mathematics and physics to test its performance under hypothetical conditions.

For example, you might want to know something as simple as whether the wing can support its own weight. To answer this, an analytic engineer could run what's called a finite element analysis to simulate how gravity affects every part of the wing.

Of course, the main purpose of a wing is to generate enough lift to keep the plane airborne. For that, they might use computer simulations of airflow to estimate the force of lift generated at different speeds and wing angles. The results an analytical engineer generates would then help the designers to improve the wing's performance.

But sometimes, hypothetical models aren't enough, which is where experimental engineers come in. Fluid flows are extremely tricky to simulate and predict. Behavior like turbulence is hard to describe mathematically, even with the help of a computer. Experimental engineers are tasked with designing small-scale prototypes to test in  real, physical environments.

If you were an experimental engineer, you'd take the improved design and find a way to recreate the wing, or even the entire plane, as a scale replica. Putting the model in a wind tunnel would then provide a real flow of air around the wing to test how its shape generates lift. This gives the designers a pretty good idea about the true lift the wing will generate, and any turbulence the plane might experience because of its shape. It also serves as a cross-check of the results that analytical engineers produce.

Once a design is put together and the design engineers have laid out a way of manufacturing it, it's time to build the real thing. Manufacturing engineers work out the practical questions of how to bring the design into existence and what specific techniques to use. This has a huge impact on the safety and quality of the final product. 

For example, the rivets that attack parts of the wing together need to be firmly installed to maintain the structural integrity of the plane. A manufacturing engineer would determine the best technique for drilling the rivet holes to precisely the right diameter and depth. That's essential for installing them in a way that efficiently transfers forces from one part of the wing to another, and keeps them from disrupting airflow during the flight.

Even once you know how to make one, you wouldn't just go out and make hundreds of planes all at once. The first one needs to be scrutinised by test engineers. They're tasked with checking that the final product meets all the specifications laid out in the design and meets quality control expectations. For your wing, that might be everything from finding its breaking point to seeing how it reacts to extreme temperatures, simulated rain, or even hail. 

Test engineers are a bit like the experimental kind, but rather than testing prototypes, they work with the final products. Faults they find can be a big deal, because so much has already been decided by the time a product is produced. 

These steps might seem kind of like a checklist, but it actually takes a lot of ingenuity and creative thinking to make progress on complex projects. At every step along the way, research engineers play a key support role to make sure that happens. They spend time finding new ways to solve problems, like using an innovative new metal alloy or a totally different wing shape to improve lift and reduce turbulence.

Outside of industry, research engineers share a bit in common with university researchers and professors. Academic engineers do research across entire fields. They might study everything from new uses of polymers to battery chemicals or even robotic limbs. In general, there's a lot of overlap with the role of a scientist.

A professor of aerospace engineering might lead a team to investigate computer techniques for modeling airflow around different objects. Those methods could then help develop new software that's used by analytical or research engineers to model plane wings. In fact, modeling the flow of fluids using computers is precisely what I worked on while undertaking my doctorate in engineering.

A doctorate, or PhD, is a specialized degree engineers often need to work at a university, and usually involves research into a new technique or idea. If you work your way up to professor, you'll also be involved in teaching students. 

Which brings us to the first stage of every engineer's career: education. Crash Course Engineering is an educational video series, so we hope you've learned a lot with us and have a newfound appreciation for the basics of engineering. But, to become a professional engineer, it's important to do well in school, especially learning math and science concepts. The next step could then be taking a training course, like an electrical engineering apprenticeship, where you could pick up relevant skills by learning from experienced engineers.

More common is attending a university to get a degree in engineering. A typical degree program will expose you to different fields and ideas, so you can work out what field you might want to enter and the kinds of work you could do. But you don't need to decide everything right away. Even if you're not sure what sort, pursing a career in engineering won't close many doors. The problem-solving skills you develop will serve even if you decide to switch fields later on. Engineers have even been known to go into law, finance, and politics.

So, however it is you choose to change the world, we hope this course has inspired you towards that goal.

In this episode, we looked at how to become an engineer and the different sorts of career paths you might choose to follow. I'll see you next time for our final episode, where we explore the greatest challenges facing the world in the 21st century.

[Outro]

CrashCourse Engineering is produced in association with PBS Digital Studios. As you plan your next steps as an engineer, why not learn more about your brain with Braincraft, a show about psychology, neuroscience, and why we act the way we do. Check it out at the link in the description.

CrashCourse is a Complexly production and this episode was filmed in the Doctor Cheryl C. Kinney Studio with the help of these wonderful people, and our amazing graphics team is Thought Cafe.