Eight amazing engineering stories download

Electronic apparatus and appliances. Engineering design I. Preface After creating our third series of EngineerGuy videos in the spring of , we started getting a lot of requests.

Specifically, a lot of people wanted to know even more about the topics we covered in the videos. The problem is that you can only put so much information into a fiveminute video. So we wrote this book to give a more complete treatment to the subjects we cover in our fourth series of videos.

In this book, we aim to educate the reader on how engineers use elements to create the world around us and to tell the fascinating stories behind a lot of the technology we see today.

Although this book covers some scientifically heavy topics, we do it in a way that any determined reader can understand. To aid the reader we have added several primers on subjects before certain chapters. For instance, before our discussion on the preparation of uranium for an atomic bomb, we have written a short primer on nuclear structure. If you feel familiar with how atoms are composed and what holds them together, feel free to skip this primer and go right to the chapter.

However, if you feel you know very little about nuclear structure, this section will provide you with the foundation you need to understand the chapter that follows. While the writing and preparation of this book involved hard work and much exhausting labor, we found it a pleasure to work together to create something that, we hope, will delight and inform our readers. March Urbana, Illinois. Introduction In this book we focus on how engineers use the chemical and physical properties of specific elements to create the technological objects that surround us.

In eight chapters, we cover eight uses of the elements: CCD imagers, tiny accelerometers, atomic clocks, fissile material for bombs and fuel, batteries, anodized metal surfaces, microwave ovens, and lasers. We have chosen to discuss these uses of the elements because they highlight the different applications that elements have in our lives. We hope that through these chapters you gain not only a deeper understanding for how these elements are used but also an appreciation for the magnificence of the innovation and engineering that go into the world around us.

After this book was written we used it as the basis for a video series. We recommend that our readers find these short videos -- none longer than five minutes or so -- at www. Although this book stands on its own the videos greatly help explain the information we share in this book by showing the principles in action. The long and significant impact of silicon on humankind can be seen from the names etymology. The root of the word comes from the Latin silex, meaning flint, because humans have been using silicon in the form of flint since prehistoric times.

Today, of course, no single element better defines our age than silicon: The element lies at the core of every one of our electronic devices. Although it doesnt conduct electricity as well as a metal, it does perform better than, say, a piece of rubber, but more importantly silicon can be made to switch internally with no moving parts between these two extremes of conductivity.

Thus creating a switch that controls the flow of electrons in circuit boards. Having a blue-gray color and nearly metallic sheen, silicon is never found pure in nature, but when combined with oxygen, it forms the most abundant compound in the earths crust: SiO2, commonly found in sand. In the next two chapters, we will look at two aspects of silicon. First, we will examine how its electronic properties allow engineers to make the CCD charge coupled device that captures images in a digital camera.

In the chapter after that, we will look at how the structural properties of silicon allow engineers to create amazing, intricate structures on a tiny scale, such as parts in smartphones.

These commonplace items perfectly highlight how necessary silicon is to our world today. As you might guess, of all the stuff Ive seen, Im fascinated most by engineered things. Ive photographed the soaring spire of the Eiffel Tower, the concrete dome of the Pantheon, ancient salt works on the border of Croatia and Slovenia, and the simple yet functional construction of huts in a Masai village in Tanzania.

Yet, I find the cameras I use to take these pictures every bit as amazing as the structures themselves. A camera both captures and records an image. In the earliest cameras, film was able to perform both tasks simultaneously. In traditional film cameras, a lens focused light onto film that was composed of a piece of plastic covered with small grains of light-sensitive silver bromide.

In the spots where light would strike, silver ions in the grains changed to an altogether different compound, metallic silver. The more intense the light, the more silver was created in a grain. The image remained latent on the film until the photographer used a chemical process to grow the silver spots until they could be seen by the human eye.

The silver areas appear dark in the negative and correspond to the bright parts of the image; different shades of gray depend on how much silver was created in a grain by the intensity of the light. In todays digital camera, these two functions are split: A light-sensitive CCD charge coupled device captures the image and then transfers it to the cameras electronics, which record it.

At some level you already understand the concept: If you enlarge a digital photograph on your computer, you can easily see the tiny picture elements the source of the word pixel that make up the image. Its easy to then understand that each of these corresponds to a section of that CCD, but how exactly does it work?

The key to understanding why digital photography became cheap and ubiquitous lies in appreciating the ingenious way that the CCD transfers the image within the camera. To make this technology easier to understand, well start the story of the CCD with a single pixel and then work our way out to how the pixels are linked together.

How a Single Pixel Measures Light Intensity Since the late nineteenth century, engineers and scientists have known that certain solids will produce current when exposed to light.

For example, take a bar of selenium a dense, purple-gray solid extracted from copper sulfate ores and attach a wire to each end. Hook an ammeter which measures current to the bar and then shine bright light on it: The ammeters needle will jump because the selenium can change the incident light into a flow of electrons.

The silicon used in a CCD exhibits a related behavior, as light causes charges to build up on the surface of the silicon. At its simplest, this defines how a pixel works: A small section of silicon -- typically a little less than 10 square microns a micron is one millionth of a meter -- in a consumer camera generates a build-up of electrons after being exposed to light.

The number of electrons trapped is proportional to the intensity of the light, a phenomenon known as the photoelectric effect. Discovery of the Photoelectric Effect In , Willoughby Smith, an engineer for the Gutta Percha Company, tested a new insulating material for submarine cables to transmit telegraph signals, which traveled at the blistering speed of 13 words per minute.

We think of an interconnected and wired world as being a late twentieth century phenomenon, but it really began in the nineteenth. Engineers like Smith connected continents by laying miles of cable on the ocean floor. By , for example, one could send a telegraph all the way from Mumbai to London via submarine cables.

In order to work, the cables could not have any electrical faults. For example, if the insulation which was made of gutta-percha, a natural latex of sorts on the cable failed, the cable would come into contact with salt water. This shorted the cable, causing the electrical telegraph signals to dissipate into the ocean. So, it was of the utmost importance to ensure the insulation stayed intact as crews laid the cable out from ships into the ocean.

As they unrolled the cable from giant spools on deck, they. If this number jumped, they hauled the cable back in and quickly fixed the insulation. To make this measurement, the end of the cable on shore had to have a high resistance. Smith did this at first by using a bar of high-resistance selenium to electrically isolate the cable. At first all seemed fine. The early experiments, he noted, cast very favorable light for the purpose required.

However, he soon noted a great discrepancy in the tests, and seldom did different operators obtain the same results. He discovered that the odd results came from boxes with sliding covers: When the cover was off, the resistance of the selenium dropped.

Smith had discovered photo-conductivity, one of several manifestations of the photoelectric effect; that is, increases in the conductivity of a solid material induced by light. The Photoelectric Effect Observed in the nineteenth century, the phenomenon of the photoelectric effect was only understood years later in the early twentieth century. In one of his earliest scientific papers, Albert Einstein was the first to explain the effect. Having read of experiments documenting the ejection of electrons from a metal after being irradiated with ultraviolet light, Einstein postulated that light existed both as a particle and as a wave.

He based his theory on three unexplained characteristics of the effect: 1. Metals will not eject electrons, regardless of the light intensity, unless the frequency of the light exceeds a threshold unique to each type of metal. The kinetic energy of the ejected electrons is linearly proportional to the frequency of the incident light. Low intensity light is able to eject electrons from metals, as long as its frequency is above the threshold of the metal.

This suggested to him that the photoelectric effect occurred when something collided with the electrons and only ejected them if something contained enough energy. He concluded that light consisted of particles, specifically photons. This revolutionary suggestion -- discounted at the time by prominent physicist Robert Millikan as bold, not to say reckless -- earned Einstein the Nobel Prize in Physics in Millikan eventually accepted Einsteins theory and won the Nobel Prize in Physics the following year for his experimental verification of Einsteins ideas.

For imaging devices, the most important aspect of the photoelectric effect is that it illustrates how light can be converted into electrical power. In a photo-conductor, light causes electrons to flow, which creates a current; in a photovoltaic cell, electrons become separated to create a voltage difference; and in a photo-emissive device, like a vacuum tube, electrons are ejected and can be used in imaging devices like photomultiplier tubes. You may think of film-based cameras as old-fashioned, but they use the photoelectric effect just like the CCD does.

The silver bromide crystals in the film that capture light are photo-conductive. Light gives enough energy to the silver bromide to cause an electron to become free from the bromide ions in the salt. This electron travels through the salt grain until it reaches the surface and combines with a silver ion to form metallic silver.

How Not to Make a Digital Camera You can see intuitively now the essence of a digital camera: Take several million of these chips of photosensitive silicon the pixels , arrange them in a grid, and capture an image. As always with engineering, the devil lies in the details. The first attempt to make digital imaging devices, pioneered by RCA, employed the most obvious method: Use wires to connect the pixels in an x-y grid.

Light striking the pixel caused a charge to accumulate proportional to the lights intensity. To read that charge, engineers attached to each photosensitive pixel an electronic gate that controlled whether the stored charge could flow out of the pixel. By sending signals vertically down the grid and then horizontally across the grid, the charges stored -- and thus the image -- could be read pixel by pixel.

In principle this would work, but in practice this method presents huge problems. All of the tiny electronic components attached to each pixel had a small capacitance; that is, they stored a little charge. So when the signal traveled down the columns, it acquired this tiny bit of charge from each of the other pixels it passed. While the charge added to the signal at each step was small, by the end, the additional. This phenomenon, which is known as capacitive coupling, introduced electronic noise that caused striations and patterns to appear in the image.

Even worse, this distortion increased as the number of pixels increased. Early x-y photo-grids had columns and rows and produced images with significant noise -- imagine using one to replace one of todays CCDs that has 1, rows and 2, columns! A CCD solves this problem in a simple way: The pixels have no wires attached to them! RCA engineers pioneered the use of photoconductive elements to record images. They arranged them in an x-y grid -- the light gray areas are pixels, connected by a grid of wires.

Charge accumulates at the center of each pixel, where the wires cross at its center. To read the charge on each pixel, pulses in the x and y directions open and close the diodes. As the x horizontal pulse moves from left to right, it consecutively opens the diodes. Diodes allow only current to flow in only one direction; the positive voltage of the pulse opens the diode.

The y pulses work the same way. The horizontal scan rate is much faster than the vertical one. That is, the vertical pulse opens a diode attached to a row, and then the horizontal pulse rapidly zips across that row, opening each pixel in that row. Then the vertical pulse moves down a row, and the horizontal pulse repeats its motion. Capacitive Coupling Capacitors in a circuit stores energy. Now, the word storage implies that capacitors introduce a time-varying element in a circuit.

Current flowing in a circuit with only resistors flows at a constant rate, but introduce a capacitor, and the flow can suddenly start or stop. While many circuits have capacitors built into them, capacitance also shows up unwanted in electronic systems, causing noise that distorts signals. For example, two unconnected wires side by side will become capacitively coupled if they are close enough. In digital systems, such as an x-y-readout imaging device, elements become so small that these effects can be large: The mess of wires creates unpredictable crosstalk that just appears as noise.

One can see how unwanted capacitance muddies a clear signal by looking at a square wave pulse. Silicon is a wonderful material for this monolithic construction because it can be made insulating, conducting, or semi-conducting by adding other elements to it.

To make the pixels within the slab, engineers start by creating insulating sections called channel stops; these divide the slab into pixels in one direction. Next, electrodes that run perpendicular to these channel stops are laid down on the silicon. A pixel, then, is a section of silicon bounded by two channel stops in one direction and three metal strips in the other.

In a moment, we'll show why three strips are critical to how the CCD operates. A CCD is created by doping silicon with a small amount of boron, which effectively adds a positive charge carrier to the silicon. Engineers then create photosensitive sections within the CCD by adding arsenic to the silicon in between the channel stops. The arsenic adds a negative charge carrier to that region of the silicon.

They cover this surface with a thin layer of insulating silicon dioxide, and then engineers deposit thin strips of metal, typically aluminum, perpendicular to the channel stops. Note that a pixel, as shown in the insert, is defined by three electrodes and two channel stops.. Just like the silver halides in film cameras or the x-y grid in early digital devices, light strikes the surface of the CCD when the picture is taken.

It passes through the gaps in the electrodes, allowing the silicon pixels to build up charge. After exposure, the CCD has captured an imagethe only problem is that it is stored as charges on the surface of a slab of silicon. To take these groups of stored charges and turn them into an image requires removing the charges from the pixels.

Recall that a camera has two essential functions: to capture and record an image. Right now, we have the image stuck as charges in the pixels.

The great innovation of the CCD was how it moved the image from the pixels to the cameras electronics without using external wires and gates that distort the image. To record the image, the CCD shifts the built-up charges from row to row until it reaches the bottom, where a read-out register transfers the charge to the cameras electronics, which in turn construct an image.

In a modern CCD, this process transfers the charge with an amazing It consists of a semiconductor the silicon covered first by an insulating layer and then by a thin layer of metallic electrodes. By varying the voltage placed across this device by the electrodes, we can create a trap for electrons, which are the charges that make up the image.

The great technological advantage of the CCD, when it was first introduced, was the way it moved a captured charge. Rather than using wires as in an x-y grid, it instead moves the electrons captured by exposure to light row by row through the solid silicon. The next two figures describe in detail how this happens. Highlighted here is a single row although all rows move that is transferred down the CCD slab until a read-out register at the bottom records the charges.

To create a pixel, we use three of these MOS structures side by side. A If we apply no voltage to the MOS, mobile negative charge carriers are distributed throughout the. B Applying a negative voltage to the metal moves electrons away from the metal-semiconductor interface.

C Applying a highly negative voltage drives electrons deep into the bulk of the semiconductor, leaving positive charge carriers near the surface.

D Using three of these MOS structures side by side allows us to create a trap for electrons. By lowering the voltage of the center electrode relative to the sides, we form a region with positive charge. When the light strikes the silicon, electrons that are trapped in this small potential well flow into the area near the surface. This creates isolated charges on the surface of the CCDs silicon, charges that are located at different points across the CCDs grid and make up the image.

Now lets turn to recording that image, or the details of getting the charge out of the pixels. Lets look at a four-pixel section plus one-third of a fifth pixel. As noted above, when light strikes the center wells, each pixel stores a charge. We then drop the voltage on the electrode to the right of each well, allowing the stored charge to migrate to the area with the lowest voltage.

We then raise the voltage on the original well, trapping this charge under the next electrode. All charges have now moved to the right by one-third of a pixel. We continue this process until all of the charges reach the bottom edge where the cameras electronics record the information from each row.

Heres what happens in detail. In the figure above, the four pixels are shown at time 1, immediately after exposure. From left to right, the pixels have two charges, three charges, one charge, and four charges trapped at the semiconductor-metal interface.

To move the charge one row to the right, the following happens: At time 2, the potential in each well immediately to the right of the stored charges drops to the same voltage as in the well to its left. This causes the charges to move to the right. Then at time 3, the. At time 4, the potential in each well immediately to the right of the stored charges drops to the same voltage as in the well to its left. The charges once more move to the right.

Then at time 5, the potential of the well that previously trapped the charges rises. At time 6, the potential in each well immediately to the right of the charges that were just moved and stored drops to the same voltage as in the well to its left.

Then at time 7, the potential of the well that previously trapped the charges rises. This completes one clock cycle: The charges in the rows have moved down a row. This continues until all of the charge is removed from the CCD. This figure shows four pixels from four different rows of a CCD and what happens at seven sequential times to these four pixels.

It may seem like a cumbersome process. Indeed it can be very slow because it is serial; that is, there is no skipping or jumping by rows. The first row must be transferred first, then the second, and the third, and so on. You can observe this row-by-row serial reading of an image in the time you need to wait between taking pictures with a digital camera.

This time delay from the serial motion is the price paid to have no wires as in an x-y device, where individual pixels can be read. The great virtue of the CCD is that it. This means a single pixel would measure the combined intensity of all light colors at the same time. We could use this to make a black-and-white image, but to make a color image we need to separate the entering light into its three components: the primary colors red, green, and blue.

It would then seem obvious to record a color image using three CCDs. Left Engineers could use three CCDs to create a color image, but this would be very expensive, so instead they use Right a single CCD covered with a color filter array. This creates an image that is a mosaic of red, green, and blue sections. Full color is restored using an algorithm. Shown here is the Bayer Color Filter Array.

Using a prism, we could split the incoming light into three rays and pass one through a red filter, one through a green filter, and the last through a blue filter.

A CCD behind each would record the intensity of each color, and then we could recombine them into a color image. Although this solution is simple, engineers rarely use such a design in consumer digital cameras because its far too expensive and requires three CCDs! Instead, they use a bit of math to create the color image. Engineers divide this array into pixel-sized sections: Some of the sections have a red filter, some green, and some blue. This means that the image that comes out of the CCD is a mosaic of red, green, and blue sections.

The camera then applies an algorithm to estimate the correct colors and fill in the picture. For example, if a red filter covers a pixel, we would need to estimate the green and blue components of that pixel.

To do this wed use the adjacent pixels. This process works because the images significant details are much larger than the pixels. Sounds impossible, but youve seen the results yourself: Every digital picture youve ever snapped likely uses this method! This should be no surprise because every engineered object is a balance or trade-off among desired properties. The quest to make both larger imaging devices telescopes, for example and smaller ones.

Making large CCDs calls for more efficient rowto-row charge transfer. Every time a transfer occurs, a little bit of charge is lost. The last pixel is the worse-case scenario: It must be transferred 1, times to the readout register, then down that register another 1, steps. For these 2, steps, the amount of charge transferred would be 0. So, to make the x CCD have the same amount lost as the x array would require somehow increasing the charge transfer to One can see that eventually the size of the CCD will outstrip any attempts to make the efficiency higher.

In addition, the CCD is slow to read because it is discharged row by row. In making tiny cameras for cell phones, the CCD has two main limitations.

First, the CCD has to integrate onto a chip with other components. Second, the CCD requires large voltages, perhaps 10 to 15 volts, that can drain a cell phone battery. Oddly, the way forward for imaging devices is to, in a way, return to the x-y devices that lost out to the CCD in the s.

The early devices suffered from severe capacitive coupling that distorted the images recorded. These early devices were passive pixel sensors PPS. New chip-making methods allow production of x-y devices with a transistor built into every pixel. In this APS device, the transistor functions as an amplifier that increases the signal from a pixel, thus overcoming the noise from capacitance.

In addition, the transistor allows digital filtering techniques to be used to reduce noise, something that could not be done in the early PPS system. Boyle and George E. Smith for the invention of an imaging semiconductor circuit -- the CCD sensor. In a way, their work on the CCD was inspired by magnetic bubble memories, which was all the rage in at Bell Laboratories. These memories used tiny magnetized spots, called bubbles, moved about by currents to store information.

This worried Boyle. As executive director for the division of Bell Labs that worked on silicon -- the dominant medium for computer memory at the time -- he worried that these new bubbles might divert funding and support from silicon research. Boyle invited his friend and colleague George Smith to help him come up with a competitor to this new technology.

On a chalkboard, they devised a way to use silicon, silicon dioxide, and metal electrodes to store charge in specific areas on the surface of the silicon. The conversation took about an hour as they jotted down in their notebooks that the device could be used as an imaging device and a display device in addition to being used for computer memory. After reflecting on their chalkboard talk for a few weeks, they decided to build a prototype CCD.

Within a week, they had a working device that proved the concept of their idea. A great engineer, Tompsett carefully turned the brainstorm of a charge-coupled device into a reality. His name alone appears on the first patent for the CCD as an imaging device; the patent was titled, appropriately enough, Charge transfer image devices. While one might feel Tompsett was overlooked for the Nobel Prize, the prize is generally given for the invention or discovery of fundamental concepts in physics.

Boyle and Smith indeed laid down the idea of a CCD, but controversy arises because the only practical application of a CCD is as an imaging device. For instance, if you drop this book, gravity will accelerate it toward the center of the earth until it comes to rest on the ground. But how does a smartphone know which way the phone is rotated, so the screen is always right-side up?

To ensure that the screen on your smartphone always is pointed in the correct direction, engineers place tiny accelerometers inside the phone to orient it with respect to the earth.

An accelerometer is a device that measures gravitational pull. But how can these tiny accelerometers tell which way is up? Basics of an Accelerometer You can see the essential principles of an accelerometer in the simple device shown in the next figure. When that device is upright, gravity stretches the spring downward, as indicated by the mark labeled 1g, meaning one unit of gravitational acceleration.

One g is what you feel with little or no other acceleration on earth; for reference, when a roller coaster car takes off you feel about 2. On the device 0g occurs when the tube lays flat so the spring feels no gravitational pull, and the spring has no extension. This distance from 0g to 1g sets the scale for marking 2g, 3g, etc. We can use this accelerometer to measure the upward vertical acceleration experienced by the tube.

If we were to quickly jolt the tube upwards, we would see the weight drop inside the tube, possibly to 2 or 3gs. Three of these basic accelerometers can be used tell us the orientation of an object. A simple accelerometer: A glass tube with cork stoppers at each end makes up the housing. The seismic mass is a lead ball tethered to the housing by a spring. In an oblong box, align one accelerometer each along the x, y and z axes.

By measuring changes in the lengths of the springs, we can detect which edge points up relative to gravity.

In the first position, the xaxis accelerometer records 1g, while in the y and z direction the weights lie against the side of the tubes and the springs are not extended. Rotate the box so it sits on its long edge, and the y-axis accelerometer will register 1g, while the x and z accelerometers will read 0g.

Although the accelerometer inside a smartphone is a bit more complex, it works using these same principles. Three of these simple accelerometers can determine the orientation of a box.

Note the change in the x and z accelerometers. When the box lies on its z-axis, the ball in the accelerometer along that axis lies flat while the spring in the accelerometer on the x-axis is extended.

When the box is rotated, the ball in the x-axis accelerometer lies flat, while the ball stretches the spring in the accelerometer along the z-axis. As with all technologies, though, power comes with peril -- even with such a seemingly innocuous object as a smartphone accelerometer.

Researchers at the Georgia Institute of Technology showed that such an accelerometer could track the keystrokes of a computer user. They placed a phone on the table beside a computer keyboard. Since the accelerometer samples a phones vibration about times per second, it would jiggle slightly with each press of the neighboring keyboard. The keyboard moved the table slightly, and the ultra-sensitive accelerometer detected these small vibrations of the table.

They compared this to a preloaded dictionary of likely words to determine the most probable word made for these pairs of keystrokes. Small wonder, then, that Melvin Kranzberg, a historian, once observed technology is neither good nor bad; nor is it neutral. The Accelerometer Inside a Smartphone The figure below shows a typical smartphone accelerometer.

Its very small, only about microns long on each side. The housing, which is stationary, is the large block at the base, to which are attached several stationary polysilicon fingers.

The seismic mass is the roughly H-shaped object with the tongues extending from it; its tethered at the ends so it can jiggle left and right between the stationary fingers. Recall that in our simple accelerometer with the weight and spring arrangement, we measured the acceleration of the box by how much the weight moved relative to the tube.

This device measures acceleration by the degree to which one of the tongues hanging off the H-shaped section moves relative to the two stationary fingers.

We did this by eye for the weight and tube accelerometer, but here we use the electronic properties of silicon. The tongue and two stationary fingers form a differential capacitor, a device that stores charge. As the accelerometer moves, the charge stored within the differential capacitor changes, causing a flow of current.

Through careful calibration, engineers can link the magnitude of the current flow with the pull that the accelerometer feels from gravity. Using a Capacitor to Make an Accelerometer We can make the simplest capacitor from two metal plates with an air gap between them, as shown in the next figure. If we hook these capacitors to a battery, current will flow as charge builds up on the plates: positive on the top plate and negative on the bottom.

Once enough charge builds up, the current stops because the. For most well-made capacitors, this situation will persist until we change something in the circuit. For example, if we move the plates a little closer, then current will flow again as the charge is redistributed. You can picture how a capacitor would be useful in an accelerometer: Imagine one plate as the housing and the other as the seismic mass.

When we hold that accelerometer stationary, no current flows. But move the seismic mass, or the top plate, and a current now starts to flow. Just as we did with the weight and tube accelerometer, we can calibrate this: Subject the two-plate capacitor accelerometer to known accelerations and measure the currents that flow.

The leftmost image shows a two-plate capacitor before the circuit is closed. There are no charges on the two metal plates. When the circuit is closed center image a charge builds up on the plates and current stops flowing.

If the plates are moved closer together, as in the image on the left, current flows until the charge is redistributed on the plates. A smartphone accelerator doesnt quite work like this, but were getting close. In eight chapters, the EngineerGuy team exposes the magnificence of the innovation and engineering of digital camera imagers, tiny accelerometers, atomic clocks, enriching fissile material, batteries, anodizing metals, microwave ovens, and lasers.

To help readers of all backgrounds, the book also includes introductions to the scientific principles necessary for a deeper understanding of the material presented in the chapters. The reader will be delighted by primers on waves, nuclear structure, and electronic transitions.

Digital Cameras: How a CCD Works This chapter discusses how silicon-based pixels use the photoelectric effect to measure light intensity.

It covers these topics:. How a Smartphone Knows Up from Down Accelerometers inside many electronic devices - tablets and phones - re-orient the screen as a user moves the device. This chapter opens by using a simple ball and spring device to explain the general principle of an accelerometer. It then describes:.

How an Atomic Clock Works This chapter lays out the essential principles and operation of an atomic clock. Specifically, it includes:. Primer: Nuclear Structure This chapter gives a brief overview of nuclear structure. It describes:. The Hardest Step in Making a Nuclear Bomb The hardest step is obtaining isotope uranium, which must be separated from uranium The chapter includes:.

The Lead-Acid Battery: A Nineteenth Century Invention for the Twenty-first Century The lead-acid battery lies at the center of our technological world: The single largest use of batteries is for starting engines of cars and trucks. This chapter includes:. This chapter reveals how this process works. It includes:. Wizard but spin to the adult science enthusiast. The most resent season he calls it series 4 scratches the surface of the topics covered in his book Eight Amazing Engineering Stories , which was written with fellow authors [Patrick Ryan] and [Nick Ziech].

They provided us with a complimentary digital copy of the book to use for this review. The conversational style found in the videos translates perfectly to the book, but as with comparing a novel to a movie, the written word allows for much more depth. For instance, we loved learning about how Apple uses anodization to dye the aluminum used for iPod cases.

The same presentation style makes the topic easily understandable for anyone who took some chemistry and math in High School. But primers a sidebars offer an optional trip through the looking-glass, explaining the history behind the process, how it compares to natural materials, and what trade-offs are made in choosing this process. Some of the other topics included are how CCD camera sensors, lead-acid batteries, mems accelerometers, and atomic clocks work. As the book progresses through all eight topics general concepts the complexity of the items being explained advances quickly.

But we still enjoyed every page. The book would make a great pool-side read.