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  • Whether you're watching this video on your laptop, smartphone, or smart watchalthough, why would you do that!? – they're all different types of computers.

  • The widespread use of computers in the last century has radically changed the economy, society and even our personal lives!

  • And, like any useful machine, engineers are always looking for new ways to build and improve them.

  • If you need evidence of how good a job engineers have done at making computers smaller, faster & more efficient, try using an old cell phone from the 90s.

  • But the relationship goes both ways.

  • While engineers are making more effective computers, computers are making more effective engineers.

  • [Theme Music]

  • Computers are a little tricky to define, but generally, you know one when you see one.

  • Technically speaking, they're machines that perform, or 'compute,' a series of mathematical calculations, like addition or subtraction, usually with electronic circuitry.

  • The exact nature of those calculations depends on the electrical inputs to the computer, and they happen much faster than humans are capable of.

  • Computers also have machinery that stores the states associated with its electrical inputs and outputs, called memory.

  • But they're so much more than glorified calculators!

  • Because computers can execute different kinds of computer programs using the same physical hardware, they're incredibly versatile tools.

  • But to be useful, computers need computer engineers.

  • Like in other fields of engineering, computer engineers are concerned with improving the various parts of a computer and developing new ways to use them.

  • Usually, that involves dealing with two main categories: hardware and software.

  • Hardware consists of the physical parts of a computer.

  • The exact components can be different depending on what the computer is for, but virtually all computers have two core parts:

  • memory, and a central processing unit, or CPU, which executes computer programs.

  • The CPU contains the electronic circuitry that actually performs calculations.

  • It can also coordinate the different processes happening in a computer simultaneously, and allocates computing resources to different tasks.

  • Memory, meanwhile, can serve a few different purposes.

  • Computer memory provides the physical space where computer outputs can be permanently stored,

  • like that picture you took of your cat trying to fit into a tiny box.

  • It also provides a temporary working space for a CPU to store relevant bits of information while it carries out a task.

  • The signals carrying that information, even if they were originally recorded as analogue, are passed between computers in digital form.

  • With digital signals, the voltages in the circuits occupy binary statessome form of 'on' or 'off' – that represent 1s and 0s.

  • Binary is the underlying representation that computers use to operate.

  • As a human, though, you're not going to sit there and manually send an enormous string of voltage signals to a CPU yourself, unless you have a lot of time to spare.

  • That's why computers tend to have what are called peripheralsthings that make it easier for people to actually use them.

  • That might include a set up like a keyboard and mouse for sending signals to a computer.

  • To see what your computer outputs, like this video, you'll probably have a screen and a speaker somewhere on the device.

  • In some cases, like on a touch screen, the input and output peripherals can even be the same thing.

  • Peripherals take human-style outputs, like keystrokes on a keyboard, and convert them into the appropriate binary signal for computers to interpret and vice versa.

  • Other hardware associated with computers includes things like printers, sensors, and network cables.

  • These are the sorts of things a computer engineer might bring their electrical engineering expertise to design and improve.

  • The other side of computer engineering involves software.

  • Unlike the hardware of your computer, which you need to physically replace to change a computer's capabilities,

  • software can be added to or changed to produce different results with the same hardware.

  • So it's essentially the programs your computer runs.

  • For example, you can write a piece of software to store the phone numbers and opening times of every pizza place in the area to your computer's memory and retrieve it as needed.

  • If you have a camera connected to a computer, you could even program the software to recognize when the pizza delivery person comes to your door and turn down your music so you can hear the doorbell.

  • In short, software is how you tell a computer what task to perform.

  • Writing software to accomplish a task on the hardware you have is what's broadly known as computer programming.

  • Those are the two main elements of what computer engineers work with.

  • On the hardware front, they find ways to physically improve the capacity of the machinery that

  • carries out computations, exchanges signals, stores them to memory, and connects everything together.

  • On the software front, computer engineering has a lot in common with programming.

  • But in addition to programming specific tasks, computer engineers might, say, find the best way to carry out a task on a given piece of hardware.

  • Or they could find more efficient forms of software that make computer programs run faster.

  • Besides for improving the general designs of computers,

  • computer engineers can also apply those skills to developing specific devices for aerospace, transport,

  • municipal engineering, medicine, and telecommunications.

  • So there are a lot of options!

  • But you can get a sense of the sorts of things computer engineers work on by looking at some of the challenges facing the field today.

  • For example, you might have noticed that when it comes to size, most commercial computers have been getting smaller over the years.

  • Things like laptops, smartphones, and gaming consoles are able to fit much more computing power into smaller hardware.

  • The reason that's happened is because more and more computer circuit components, like transistors, were developed to fit into less and less physical space.

  • In fact, since the 1970s, the number of transistors able to fit on a computer chip has doubled roughly every two years!

  • That's what's known as Moore's law, named after American engineer Gordon Moore.

  • Moore's law describes how engineers have managed to create more sophisticated computers in smaller physical spaces.

  • But the law may not last much longer, because we're approaching the limit of what we can do with electrons.

  • Some think Moore's law has already ended.

  • Electrical components are meant to direct the flow of current in a particular way.

  • For example, transistors use a smaller current to stop and start the flow of a larger current.

  • But that job gets tricky as you shrink the components down.

  • A thin channel can often be hard for the electrons in the current to pass through.

  • And if you're packing all that circuitry right next to each other, you also have to keep the current from hopping from one circuit to another.

  • Not to mention, you have to be able to make your transistors out of something.

  • To keep shrinking them down to fit more of them onto a computer chip, you need to use less and less material for a single transistor.

  • Eventually, you'll have to build your transistor from just a few individual molecules, or maybe even just a few atoms.

  • But you can't really build with anything smaller than that!

  • To reach the limit of tiny electrical components,

  • engineers are looking into alternatives to the standard way we've been constructing transistors, like by using nanotechnology.

  • Some nanoengineering designs aim to create transistors that operate on a current of just a single electron.

  • There are already chip manufacturers on their way to developing transistors just five nanometers longso a few dozen atoms wide.

  • But having a large number of transistors, while generally great for computing purposes, creates other issues.

  • One major consideration is the energy computers need.

  • Like most sophisticated electrical devices, the internal circuitry consumes a lot of power.

  • Providing all that power is becoming more of an issue.

  • Computers are being designed with greater processing power in their CPUs and bigger amounts of memory storage, which all generates more energy demand.

  • Right now, about 3% of the energy produced on Earth is used for computing.

  • So making computers more energy efficient would not only reduce the amount of carbon dioxide released from burning fossil fuels,

  • but it could save large companies billions of dollars.

  • Engineers have a few tricks up their sleeves to try and tackle this.

  • A lot of the actual energy consumption comes from producing the binary signals computers use, the 1s and the 0s represented by voltages being turned on and off.

  • In the memory, the smallest unit of that signal, called a bit, is stored by changing the state of an electrical component,

  • such as turning a transistor on or off, or by charging up a capacitor.

  • Switching a bit from a 0 to a 1 or vice versa takes some amount of energy.

  • So engineers are looking into methods of computing that can somehow keep the “1” bits intact as they're passed through the circuit,

  • so they don't have to be rewritten during processing, saving energy.

  • On the software side, computer engineers are also developing algorithms, special sets of rules used in computer programs, that work more efficiently.

  • For example, they've developed ways of sorting and searching for information that require fewer calculations to be performed by the computer, which can also save lots of energy.

  • Even better, using less electrical energy means less heat building up within the computer,

  • which in turn could allow computers to operate faster.

  • So that's what engineers are doing for computers.

  • But computers are also doing a lot for engineers.

  • For example, computers are essential for the control systems we've talked about,

  • automating the measurement and adjustment of industrial devices like heat exchangers to make sure everything operates smoothly.

  • But computers can also help engineers design and create components for use in other fields of engineering.

  • That's accomplished by Computer Aided Design and Computer Aided Manufacturing, or as they're more commonly called, CAD and CAM.

  • CAD is the process of using special software to design two or three dimensional objects on a computer.

  • With CAM, you take those CAD designs and manufacture them.

  • Both CAD and CAM allow for well designed, precise, and replicable components.

  • For example, printed circuit boards, or PCBs, are found in lots of common household electronics, like remote controls.

  • Designing them can be tricky, and you don't want to have to print several prototypes using an expensive material like copper to test each one as you improve the design.

  • CAD software provides tools to model your design on a computer before physically manufacturing it.

  • You can then check various design elements in the model and simulate what might happen in your circuit before it even exists.

  • That saves the material, energy, and time needed for testing physical components.

  • In the same way, it's easier to see if a complicated system of gears and pulleys is going to work as intended on a computer,

  • rather than having to assemble them every time.

  • Plus, CAD designs are useful for detailing the exact specifications of a component and sharing them with other engineers in a convenient way.

  • Of course, once you're happy with your design, you'll want to create the object in real life.

  • CAM is simply the process of taking the designs you created using CAD and interfacing with manufacturing machinery, like circuit board printers or laser cutters,

  • to tell the machine how to actually produce the components you've designed.

  • Both CAD and CAM are used everywhere in industry, from designing and manufacturing cars to making custom golf putters.

  • NASA engineers are also testing ways to use CAD and CAM to help astronauts on the International Space Station.

  • They can use CAD to design tools here on Earth, then send them up to the station to be printed on the 3D printer up there.

  • So even engineers who aren't strictly computer engineers should be familiar with computers.

  • Programming is also used in a wide range of engineering disciplines,

  • and the most complex and sophisticated machines are often operated, or at least designed, using computers.

  • So, however you choose to apply your engineering skills, computers are a tool you probably can't do without.

  • And with the work being put into computer engineering, the computers of the future will be even better.

  • Although they might still bug you about software updates.

  • In this episode we looked at computers and computer engineering.

  • We looked at the 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.

  • Crash Course Engineering is produced in association with PBS Digital Studios, which also produces ReInventors,

  • a show that introduces you to the scientists and tinkerers on the cutting edge of green technology.

  • Subscribe at the link in the description.

  • Crash Course 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.

Whether you're watching this video on your laptop, smartphone, or smart watchalthough, why would you do that!? – they're all different types of computers.

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Computer Engineering & the End of Moore's Law: Crash Course Engineering #35

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    林宜悉 posted on 2020/03/30
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