Science Communication

The blue LED was supposed to be impossible—until a young engineer proposed a moonshot idea.

What’s with all the "G"s and why do we keep having to develop new ones to use our phones in this technological age?

This week we’re exploring a field of engineering that is essential to how you’re watching this video: computers and computer engineering. We’ll explain differences between hardware and software, how engineers are working on making computers smaller and more energy efficient, and how computer aided processes such as CAD and CAM make it easier for engineers to design and manufacture parts needed in machines and products.

What can you do with a math major? Math is the study of patterns and abstract relationships, in both the real world and the lofty realms of pure theory. Basically, math is about understanding patterns, quantifying relationships, and reaching logical conclusions. A degree in math can equip you with quantitative problem-solving skills that are highly sought after in many careers. If self-study, creative thinking, persistence and deep, intricate logic all sound appealing, then a math major could be the right choice for you! Script edited by Rachel Alatalo

Artificial intelligence is making its way into every corner of our world. But when leaders in the AI space raise concerns, it's helpful to know what they're worried about. Here's how AI works today.

The bigger the electrical current, the more powerful the magnetic field. And we've learned to harness the power of those magnetic fields to do things like accelerate particles and suspend plasma! Five Of The Most Powerful Magnets On Earth

The ability to produce synthetic spider silk would give us bulletproof vests better than Kevlar, biocompatible sutures and wound dressings, and even space elevators. The problem is being able to make it in large amounts. One group may have solved that problem, and changed the definition of "toughness" in the process.

Almost all matter in the universe should have been annihilated shortly after the Big Bang, but looking around, we see galaxies, stars, planets, and, you know... us. So obviously that didn't happen, and the why of it may have something to do with neutrinos.

The blue LED was supposed to be impossible—until a young engineer proposed a moonshot idea.

Scientists like to measure things, but they've had a heck of a time doing that with sharpness. And even if no one agrees on exactly how to measure it, our search for better tools has recently led to some of the sharpest objects we’ve ever created.

The bigger the electrical current, the more powerful the magnetic field. And we've learned to harness the power of those magnetic fields to do things like accelerate particles and suspend plasma! Five Of The Most Powerful Magnets On Earth

Artificial intelligence is making its way into every corner of our world. But when leaders in the AI space raise concerns, it's helpful to know what they're worried about. Here's how AI works today.

Fusion power is supposed to save us from fossil fuels, so when is nuclear fusion going to be a viable option and why has it been so elusive?

What’s with all the "G"s and why do we keep having to develop new ones to use our phones in this technological age?

Fire: it's beautiful, it's dangerous, and it shows up in surprising places. Here are five weird things you might have on hand that can go up in flames.

Whether it's robots under the sea, wave detectors in space, or star-power on land, this episode has big experiments covered.

Did you know that ancient acoustics can give us a peek into the past? Many ancient buildings & structures have incredible effects on sound waves, suggesting that early cultures built these spaces that way for a reason. By studying these ancient sites we can learn new things about the past and the people that lived there, thousands of years ago! Join Hank Green for an amazing acoustic adventure back in time.

If you want to improve your wireless internet signal, we've got a few things to keep in mind.

The ability to produce synthetic spider silk would give us bulletproof vests better than Kevlar, biocompatible sutures and wound dressings, and even space elevators. The problem is being able to make it in large amounts. One group may have solved that problem, and changed the definition of "toughness" in the process.

Future advances in engineering may come from chemistry. From molecular motors to salt-shaker-drug-deliverers, the future looks small.

In this episode we looked at robots and the engineering principles of robots. We learned how robots use sensors to interpret their environment, how actuators and effectors allow a robot to manipulate the objects around it to accomplish a task, and how computers coordinate the efforts of the two.

Can we change the blueprints of life? This week we are exploring that question with genetic engineering. We’ll discuss how selective breeding can improve agricultural practices, and the potential DNA-level engineering could have on other fields of engineering. We’ll also look at how optogenetics and CRISPR have opened up new ways for genetic engineers to change the DNA inside living cells.

While you might not think about quantum mechanics being part of your everyday life, it turns out that it might play a role in some of the most familiar things, from the sunlight in the trees to the nose on your face!

Almost all matter in the universe should have been annihilated shortly after the Big Bang, but looking around, we see galaxies, stars, planets, and, you know... us. So obviously that didn't happen, and the why of it may have something to do with neutrinos.

Hopefully this course has gotten you excited about all the things we can do with engineering. If so, today we’re going to try to help you answer a very important question: how do you become an engineer? What are the steps? What kinds of careers can you pursue?

This week we are looking at renewable energy sources and why we need them. We’ll explore hydropower, wind, geothermal, and solar power, as well as some of the challenges, and how engineers are working to make their use more widespread.

Diamonds are iconic, but some of them might make others a little green with envy.

From removing glare in windows to making pacemakers safer, monolayers hold a number of possibilities for advances in future technology.

Artificial Intelligence always takes over humanity in the movies when it gains consciousness. But even without getting into sentience, it's capable of influencing our lives in a lot of ways already.

This week we are exploring alternative energy sources. We'll look at how biomass can be burned as a fuel source, how hydrogen can be used in a fuel cell to generate electrical power, and how nuclear fission provides power to the grid. We'll also discuss how nuclear fusion might someday do the same without any radioactive waste.

In our final episode of Crash Course Engineering we are going to take all the tools and ideas we’ve discussed throughout this series and try to imagine where we’re headed. We’re going to explore some of the biggest problems that today’s engineers are trying to solve and make some guesses about what the future of the field might look like.

You may not realize it, but your body is like a fortress, designed to defend you from tiny foreign invaders known as pathogens. This seemingly small world is actually super diverse, and sometimes super dangerous too.

This week we’re exploring a field of engineering that is essential to how you’re watching this video: computers and computer engineering. We’ll explain differences between hardware and software, how engineers are working on making computers smaller and more energy efficient, and how computer aided processes such as CAD and CAM make it easier for engineers to design and manufacture parts needed in machines and products.

In a nuclear explosion, how close you are impacts your chance of survival. But who you are also has more influence than you might think. If everyone on Earth were equidistant from the bomb, here's the last person standing.

Devices that collect data about our bodies need power, but they also might need to be very small or even ingestible. To avoid including batteries in these cases, researchers are looking for ways to harvest energy from the body itself.

You might finally be able to watch that 4k video without buffering, thanks to quantum mechanics and orbital angular momentum.

Today we’re looking at silicon, and how introducing small amounts of other elements allow silicon layers to conduct currents, turning them into semiconductors. We’ll explore how putting two different types – N and P semiconductors – together gives us electrical components like diodes, transistors, and solar cells.

Thomas Edison often gets credit for the invention of the light bulb, but a good argument can be made that they were around centuries earlier in the form of barometric light.

Optogenetics may allow us to use light like a remote control for our brains, and treat diseases like retinitis pigmentosa.

It’s probably not a surprise that many ancient texts are a bit worn out and tattered, and that makes deciphering what they say quite a task. But with new computer tech and artificial intelligence, we are getting much clearer glimpses of what people of the past thought was important enough to write down.

If you've ever had a pest problem in your home or garden, you may have come across diatomaceous earth as a bug-killing option. This white powdery pest control is made of 100% pure fossils, and we don't just use them for killing bugs! They're used in tons of things, including in nanotechnology!

As we react to the predictions that epidemiological models make, changing the ways we act and go about our lives, those estimates can appear totally off. But if a model’s predictions end up being wrong, that might mean it's done exactly the job it was supposed to.

Sometimes, you ask ChatGPT to do a math problem that an arithmetically-inclined grade schooler can do with ease. And sometimes, ChatGPT can confidently state the wrong answer. It's all due to its nature as a large language model, and the neural networks it uses to interact with us.

Today we’re going to start thinking about materials that are used in engineering. We’ll look at mechanical properties of materials, stress-strain diagrams, elasticity and toughness, and describe other material properties like hardness, creep strength, and fatigue strength.

There are batteries powering so many parts of our everyday lives, so today we’re going to talk about how they work and how we can make them better. We’ll explain how they provide power by discharging ions between a cathode and an anode, and how reversing that process gives us a way of charging them. We’ll also look at how that batteries deliver voltage differently over time, leading to discharge curves, and some of the work being done to improve the properties of batteries for portable electronics.

Welcome to Crash Course Outbreak Science! What do pathogens actually do to us that makes us sick? Why do societies respond to outbreaks of infectious diseases the way they do? How can we stop the next outbreak? These are the kinds of questions we'll ask ourselves and answer as best we can over the next 15 episodes of this series. Join us and Dr. Pardis Sabeti as we look at outbreaks from the microscopic level, to the big picture, so that we can work together to stop future outbreaks and create a healthier future for everyone.

Engineering helped make this video possible. This week we’ll look at how it’s possible for you to watch this video with the fundamentals of signal processing. We’ll explore things from Morse Code, to problems like bandwidth capacity and noise, to how we arrived at the digital age.

Infectious disease has affected the human species for as long as we’ve existed, but in that time we’ve come a long way in understanding what they are and how they spread.

In this episode, we looked at food engineering. We explored how food’s capacity to spoil makes it a unique challenge from an engineering viewpoint. We saw how many branches of engineering come into play to process ingredients, ensure safety for consumers, and package food, as well as how thermodynamics is involved in the different stages of food production.

This week we’re going underground to explore geotechnical and seismic engineering. We’ll look at how structures connect to the ground and transmit loads through their foundations, and how those foundations need to provide a high bearing capacity. We’ll see how properties of the soil, like shear strength, affect bearing capacity. We’ll also consider happens when the ground experiences stress from seismic activity and how seismic engineers work to counteract those effects.

Transportation is a big part of our world and engineers play a big role in making it happen. Today we’ll explore how transportation systems are designed and some things transportation engineers have to take into consideration, like signaling, user behavior, and traffic flow. And, of course, we’ll talk about some of the ways that transportation engineers are trying to improve the systems we already have.

Fluorescent molecules are useful for a lot more than just making you look cool at your local rave. Fluorescence turns out to be a kind of chemical superpower that lets us tackle all kinds of problems, from solving crimes to saving lives!

All the complexity in the universe ultimately owes its existence to one of the simplest materials possible: molecular hydrogen. And not only did this molecule play a huge role in building the universe as we know it, today, it also helps us explore it.

Today, we'll explore the materials electrical engineers work with. We'll look at high-conductors, insulators, and how low-conductivity conductors can be used to generate light and heat.

An essential part of engineering is engineering design. Today we’ll see how design synthesis helps you put together the components of a process and decide what techniques are needed to solve your problem. We’ll explain the need test things on a smaller scale before ramping up to full production, and how to continually incorporate feedback from design flaws to improve your designs.

It can be really important to separate out chemicals for all kinds of reasons. Today we’re going over three different processes engineers use to achieve that separation: distillation, which separates substances based on their different boiling points; liquid-liquid extraction, which uses differences in solubility to transfer a contaminant into a solvent; and reverse osmosis, which filters molecules from a solvent by pressurizing it through a semipermeable barrier.

Given that Earth’s magnetic field helps protect its life-sustaining atmosphere, you might think that the stronger a planet’s magnetic field, the better. But as it turns out, some planets’ relationships with their magnetic fields are a little more complicated.

We take it for granted that society gets better at tackling infectious disease over time, but when you really think about it the progress we’ve made in the last century is pretty amazing. How does that much progress happen so quickly?

In the fight against diseases like cancers and blood disorders, sometimes we need to turn to unexpected allies. And in this case, one of those allies was a tiny little nanobody hiding inside of... camels.

Engineering, like life, could really use a lot more cheese. This week we are looking at a cheese factory in Toronto and what it can teach us about process control systems. We’ll explore feedforward and feedback systems, and see how integrating them both with the final check of cascade control creates a system made to handle uncertainty the world throws its way.

Throughout this series, and in our real lives, we've seen the chaos and devastation that outbreaks can cause. But there's good news! Eventually, outbreaks come to an end. In this episode, we'll look at some of the important tools of outbreak response, particularly vaccines, and also discuss the important work that happens in the aftermath of an outbreak.

Driving can be dangerous, especially if you’re trying to juggle a variety of distractions while barreling down a busy highway. So scientists are looking into ways to keep us focused on the task at hand, even if you’re traveling in an autonomous vehicle.

What if you were on a high floor of a skyscraper and the building started swaying? Today we’ll explore statics and dynamics, and what they mean for the structures we design. We look at the idea of static equilibrium, forces, and torques, and how free body diagrams can help us make sense of it all.

Could an edible computer be in your future? Researchers are currently working on several of the components you find in them, from batteries to circuit boards to logic gates.

At the heart of outbreaks are people! People are the ones who get sick, transmit diseases, and change the way they live in response to outbreaks. In outbreak science, we can better understand the relationship between people and disease through the discipline of epidemiology.

This week we’re headed out to sea for some marine engineering. How do we design ships to handle aquatic environments? How do we deal with marine life and corrosion and all of the other problems that come with engineering in the ocean? How can large maritime structures be built on land and transferred into water?

Sometimes, diagnosing patients is pretty easy, but other times... not so much. Luckily, in a medical setting we have tools that can help us figure out what's wrong with patients, and how to help them.

We’re all susceptible to infectious disease of some kind or other, but not everyone is equally likely to be the victim of an outbreak. The fact is, inequalities both between and within communities mean that some people are at higher risk than others.

A sad reality that we have to face when studying outbreak science is that sometimes groups of people use outbreaks intentionally to inflict harm on another group.

When we think of how we respond to outbreaks, we often think of physical things like vaccines or medicines, but there is another factor that is just as critical to understand: culture! Culture determines how we collaborate and use the resources at our disposal in the face of an outbreak.

At some point in life, you've probably been faced with big-picture questions and everyday problems that share one thing in common: math. The truth is math is all around us, from trips to the supermarket to following stock market trends, some situations are more simple or complex than others. In this 30-episode series, Jason Guglielmo, math education researcher and teacher, helps us better understand math and how we interact it with every day.

Scientists have found a way to hack the visual process and generate shapes directly on the brain, so a person can see them without using their eyes.

When you think about the technology that helps us prevent outbreaks, what do you think of? Vaccines? Lab tests? Medications? What about toilets? That's right! Toilets are an important piece of technology that can help us prevent outbreaks!

Over the course of this series, we've seen that outbreak science is actually MANY sciences, including biology, epidemiology, sociology, and even economics! Because outbreak science is an interdisciplinary field, everyone has a role to play in ending outbreaks, including you! In this final episode of Crash Course Outbreak Science, we'll take a look at how different fields come together to prepare for and prevent outbreaks.

Day to day, hospitals provide all kinds of services to help us get better and stay healthy, but during an outbreak, hospitals are the front line of the emergency.

When outbreaks happen, we need to be able to predict the course they’ll take in the future, but of course we can’t run experiments on real people to figure that out. Thankfully we can simulate outbreaks and use models to find out how different scenarios could play out!

Public health activities are all the ways society coordinates to deliver better health to people.

Computers are an essential part of everyday life, from running our cars to enabling lightning-fast communication around the world. And that incredible versatility comes from the different programs they run. Amazingly, this power is something everyone can harness through programming, which is writing programs. This episode takes us through the main functions of a computer and some of the core concepts in the programming process.

In 1959, the WHO set out to eradicate smallpox, an ambitious goal that was achieved by 1980. But this goal wouldn't have been possible without coordination on all levels of society.

What can you do with a math major? Math is the study of patterns and abstract relationships, in both the real world and the lofty realms of pure theory. Basically, math is about understanding patterns, quantifying relationships, and reaching logical conclusions. A degree in math can equip you with quantitative problem-solving skills that are highly sought after in many careers. If self-study, creative thinking, persistence and deep, intricate logic all sound appealing, then a math major could be the right choice for you! Script edited by Rachel Alatalo

We constantly come across patterns and the use of logic in our everyday lives. We are able to tell things apart while also knowing what they share in common and relate to one another. In this episode, we discuss set theory, which gives us the tools we need to understand patterns, ask questions and find precise answers both in math and the real world!

What can you do with an information technology degree? Information Technology (IT) is a topic that explores computing infrastructure and how to manage it in the context of an organization. A degree in IT can equip you with technical skills highly sought for by different employers looking to use technology to be more effective. If problem-solving, tinkering with computers, analytical and creative thinking all sound appealing, then an IT major might be the right choice for you!

Memorizing and keeping track of lots of details, like numbers and text, is essential for the kinds of complicated tasks we want computers to do. In this episode, we explore the different systems of computer memory, what they accomplish, and how we make use of them in programming using variables.

One of the main purposes of programming is to get a computer to do data crunching that would be difficult or tedious for people to do. In this episode, we explore the basic building blocks for getting computers to do useful things with data: expressions.

To understand the world, we group things together: people, computer files, trees, Italian restaurant fan favorites… you name it. But who says that my understanding is the same as your understanding? That means we need ways to evaluate other people’s stories, so that we can craft our own opinions on big issues. Statistics is humanity's best toolkit for distilling data about lots of stuff into reliable and comprehensible conclusions about everything from cookies to climate change. Your journey to mastering this essential subject starts here.

There are a lot of different ways we can order a collection of objects, and the possibilities can quickly add up. In this episode, we discuss how through math, we can make sense of all the possibilities using the concept of permutations.

Visualizing how different sets fit together using a few simple circles is often easier than trying to keep track of the data in our heads. In this episode, we discuss how Venn diagrams help us visualize multiple pieces of data, understand the relationship between sets, and notice patterns we might not have initially seen!

Life is full of uncertainty and when we have any sort of question with unknown possibilities, we're dealing with probability. In this episode, we discuss mathematical probability and how math helps us predict what will happen. During our next couple of episodes, we’ll use our knowledge of sets, counting, and permutations in the world of probability theory, the branch of math where we study different ways to assign numbers and calculate how likely something is to happen or to be true.

While there's times when arranging groups and objects in a specific order matters, sometimes we just don't care about the order. In this episode, we discuss combinations and how this process can cut through big numbers and give us practical answers. This episode marks the end of our exploration of sets and counting! The concepts we’ve developed along the way (intersections, subsets, and the fundamental counting theorem) will come in handy as we venture into the worlds of probability, statistics, and geometry.

The magic of programming is that a little goes a long way. With just a few simple elements of Java: declaring variables, assigning values with simple expressions, inputting data and printing it to a screen, we have what we need to write complete Java programs to tackle problems including... radioactive mice?? Sound Design by Andrew Smith

From rooftops and collections of objects, to GPS navigation satellites orbiting Earth, everything in the world around us is at some kind of an angle. Geometry has a whole set of tools for making use of all these angles everywhere: trigonometry. In this episode, we discuss the world of trigonometry and the mathematical functions it uses to describe the relationship between sides and angles.

Understanding variation and how data is dispersed helps us grapple with the thing that makes the data interesting in the first place. Sometimes to capture valuable information we need to go beyond averages and explore the math behind how spread out our data is. In this episode, we discuss measures of dispersion and how this tool can give us more insight into our sets of data.

When planning for the future and attempting to make choices, chance and probability can play a trickier role than we might expect! Whether two events depend on each other or not, can drastically affect the results of your predictions. In this episode, we discuss independent, dependent, and conditional probabilities and all the ways outcomes can be influenced by the relationship between events!

To make sense of the world, we need to understand cause and effect. Like, does caring for your bougainvillea make you happy, or does being happy make you likelier to take care of your plant? Answering questions like these involves statistics — including dependent and independent variables. This episode dives into what those variables are, and how they set the scene for investigating the hidden relationships between nearly everything.

Our eyes and brains combined are incredible information-processing machines which is why we can often understand things more quickly by looking at visuals. In this episode, we discuss how we can get the deeper meaning behind data by visualizing the information we have available to us.

Although we tend to think of computer programs executing in a tidy path from input to output, a simple trick called recursion lets us twist computer programs into repeating themselves. As weird as it sounds, recursion can actually help keep our code readable, manageable and easier to change down the line!

Dealing with data means creating order from chaos. And for thousands of years, we’ve had an ingenious way of doing just that: the table. The simple act of putting data into columns and rows is a transformative tool for navigating complex information. In this episode, we’ll explore how this humble tool can change our understanding of the world around us.

While getting money for free is a rare occurrence, there are ways in which you can make your money grow! In this episode, we discuss compound interest which can have dramatic effects in how we approach borrowing and lending money as well as help us make important financial decisions when it comes to spending, saving and investing.

When you’re solving a repetitive problem with a Java program, you’ll probably want to use a loop. And a big part of programming is choosing the right tool for the task at hand! The while loop is great when you need flexibility in when the loop stops, but the for loop is the best tool for the job when you know exactly how many times you want your program to repeat.

You've probably heard the saying "Money Makes the World Go Round" and while on its own, money may not do much, you can certainly use it to do plenty of things. Knowing how to use and manage money can help you navigate the world and accomplish goals. In this episode, we dive into the world of finance and discuss interest and its effect on each of our financial decisions.

Whether you’re studying temperatures in a neighborhood or car mileage, you’ll find the normal distribution popping up in all sorts of places. That’s no coincidence! There’s a deep mathematical reason for this conspiracy of normal distributions everywhere, which has made waves throughout history: the central limit theorem. In this episode, we’ll learn more about it and why it matters.

Units are the way we measure things, like, meters and feet; the U.S. dollar and the Euro, or Celsius and Fahrenheit. And, depending on the context, people often use different units for the same problem. In this episode, we discuss Dimensional Analysis, a toolkit math provides for dealing with all the different choices of units and conversions.

Whether it’s painting, constructing, wrapping things or even just designing a soda can, understanding surface areas is essential to designing the world around us. And being able to move between two and three dimensions with this type of thinking helps us learn more about the shapes that we interact with. In this episode, we discuss surface area and the ways in which this knowledge can help us navigate and better understand the world around us.

The bell-shaped curve we find in Normal Distributions is defined by two things: mean and standard deviation. These factors can help us understand more complex problems that are not-so-standard. In this episode, we discuss Non-Standard Normal Distributions and how we can lean on simpler concepts we already understand to solve more unusual ones.

It’s time to put our knowledge about for loops into practice! In this episode, we’ll revisit our radioactive mice and see how programming in Java can help us solve even more questions about them, including modeling their movements with Brownian motion.

Right angles are just about everywhere. We see them in everything from coffee tables to buildings, from washing machines to gaming consoles. They’re part of the way we use vectors in linear algebra, and understanding them opens up doors beyond the realms of geometry. In this episode, we discuss right-angled triangles, the mathematical methods for calculating them and how these pop up just about everywhere, from lurking in the physical space to the theoretical level when dealing with abstract relationships!

The normal distribution pops up all over the place, but it’s more than just a haunting bell curve — it’s also really useful to us in everyday life. In order to take advantage of all that it offers us, though, we need a way to measure how much our data really resemble a normal distribution…and then things become as easy as 1, 2, 3.

Calculating a “central tendency”, like an average, is one of the most powerful ways we can meaningfully represent data. But we also need to understand how data are spread out beyond that average, which is why we have variance. Measures of variances and measures of central tendencies form the two most common “opening moves” in the game of data analysis.

When talking about interest and how it affects the money we borrow or lend, it's not always just a matter of deciding between simple and compound interest. Time is a factor that is just as important; not just how much time has passed but the units of time we use to measure. This is where the compounding period comes in. In this episode, we discuss compound interest and the ways in which time affects it.

Climate change and industrial activity, diets and disease, or even who’s on shift and the odds of a free muffin: some of the biggest challenges in statistics are about investigating relationships between two things. To disentangle what influences what, we need the tools to calculate complex probabilities.

Statistics is critical in helping us figure out whether the world looks the way we expect it to. That can include everything from how things fall into different categories, like the books we read, or even what neighborhood we’re in. And the chi-square test is exactly what we need in hypothesis testing to measure how well a model fits reality.

It’s easy to jump to conclusions too fast. Sometimes it helps to play the skeptic! And using the null hypothesis helps us make informed decisions and slow our roll a bit — by assuming that nothing has changed, and that we’re maybe just not on our A-game perception-wise.

Knowing how much space things occupy is important because… well that’s sort of what the whole universe is! Space with objects in it. In the three dimensions that we’re familiar with, the way we measure the space that stuff takes up is called volume, and it’s another way math helps us get to the heart of objects that make up the world around us. In this episode, we discuss volume and the tools that can help us handle more complicated physical structures and the spatial relationships that we encounter in everyday life.

Stats help us figure out when stuff is different, like the traffic levels in two different neighborhoods. But that opens up more questions — is one thing more or less than the other? Or just different in some unknown way? How can we be sure? The answer lies in tails and testing. More specifically: one and two-tailed tests.

There are relationships between numbers and groups lurking everywhere. Do the views on your selfies depend on the day of the week? Do certain species of trees boost bird populations? Untangling relationships like these depend on the powerful statistical tool of analysis of variances, or ANOVA. And get ready, because it’s going to make group differences a statistical breeze.